Cardiovasc Interv and Ther (2018) 33:46–54
https://doi.org/10.1007/s12928-016-0434-9

ORIGINAL ARTICLE

Impact of preprocedural atrial fibrillation on immediate and longterm outcomes after successful percutaneous mitral valvuloplastyof significant mitral stenosis
Shiro Miura1 • Takeshi Arita2 • Takenori Domei3 • Kyohei Yamaji3 •Yoshimitsu Soga3 • Makoto Hyodo3 • Shinichi Shirai3 • Kenji Ando3

Received: 7 March 2016 / Accepted: 23 September 2016 / Published online: 5 October 2016 The Author(s) 2016. This article is published with open access at Springerlink.com

Abstract Optimal time to perform percutaneous mitralvalvuloplasty (PMV) for patients with significant mitral
stenosis (MS) and atrial fibrillation (AF) remains controversial. We sought to identify prognostic factors andevaluate long-term clinical outcomes after PMV of 77
consecutive patients with MS with a mitral valve area
(MVA) \1.5 cm2. According to baseline heart rhythm,
these patients were divided into sinus rhythm (SR; n = 24)
and AF (n = 53) groups. The study endpoint was defined
as a composite of all-cause mortality, admission for heart
failure, mitral valve surgery, repeated PMV, and major
cerebral vascular accident during follow-up. After successful PMV, there was no significant difference between
the two groups in post-MVA and post-mitral mean pressure
gradient. However, the New York Heart Association
Functional Classification post-procedure was worse in the
AF group (p \ 0.01). In the AF group, event-free survival
during follow-up was significantly lower compared withthat of the SR group (p = 0.016). Independent predictorsof clinical events were AF [hazard ratio (HR), 2.73; 95 %confidence interval (CI), 1.04–9.36; p = 0.03] and pulmonary artery systolic pressure (HR 2.57; 95 % CI
1.18–5.47; p = 0.017). Patients with AF at baseline weresignificantly associated with worse symptoms and higher& Shiro Miura
shirotan1027m@yahoo.co.jp
1

Department of Social, Human and Mathematical Sciences,
University of Southampton, Highfield, Southampton,
Hampshire SO17 1BJ, UK

2

Department of Medicine and Biosystemic Science, Kyushu
University Graduate School of Medicine, Fukuoka, Japan3

Department of Cardiology, Kokura Memorial Hospital,
Kitakyushu, Japan

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event rates after successful PMV compared with those with
SR. The clinical benefit of PMV may be considered forpatients with MVA \1.5 cm2 before the onset of AF.
Keywords Mitral stenosis  Percutaneous mitralvalvuloplasty  Atrial fibrillation  Long-term outcome

Introduction
Since its introduction in 1984 by Inoue [1], percutaneous
mitral valvuloplasty (PMV), which is also well known aspercutaneous transluminal mitral commissurotomy(PTMC), has been established as a safe and effective procedure for the treatment of symptomatic mitral stenosis(MS) [2–4]. The decrease in the incidence of acute rheumatic fever in developed countries led to a sharp decreasein the incidence of MS [5]. This decrease modifies clinicalpresentation, and MS is now encountered in patients withthe characteristics as follows: advanced age, atrial fibrillation (AF), history of surgical commissurotomy, repeated
PMV, and severe impairment of valve anatomy. Previous
studies have demonstrated that valve morphology predicts
event-free survival [6, 7]. Therefore, mitral valve replacement (MVR) is the ideal therapeutic option for patientswith remarkable mitral valve degeneration.
The development of AF is a common condition and an
essential sequela in patients with MS that is associated withhemodynamic and clinical deterioration. AF may affectsymptoms and clinical outcomes in patients with MS and
AF. For example, AF is associated with suboptimal
immediate results and midterm outcome after PMV [8–10].
However, it remains controversial whether AF is an
essential independent predictor of long-term outcomes
after successful PMV for predominantly pliable MS.

Impact of preprocedural atrial fibrillation on immediate and long-term outcomes after…

Therefore, we sought to identify prognostic factors andevaluate long-term clinical outcomes after PMV in patientswith MS with sinus rhythm (SR) and AF.

Methods
Study population
We retrospectively enrolled 84 consecutive patients with
MS who underwent PMV in our institution between March
2000 and March 2009. Following 7 patients were excluded:
5 patients with cardiac tamponade and 2 patients withsevere mitral regurgitation (MR). Finally, 77 patients whoachieved immediate procedural success (defined as mitralvalve area (MVA) C1.5 cm2 and MR B) were analyzed.
Patients were divided according to baseline heart rhythm
into a SR group (n = 24) and AF group (n = 53) (Fig. 1).
After PMV, they were effectively treated with warfarin.
Further, those who converted from SR into AF during
clinical follow-up after PMV were also administered warfarin. This study was approved by our Institutional Review
Board.
Percutaneous mitral valvuloplasty
PMV was performed using the Inoue balloon technique[11]. Briefly, the procedure was performed by experienced
interventional cardiologists, and conventional hemodynamic parameters were monitored during the procedure.
Initial balloon size was selected according to body surface
area and mitral annular size measured using echocardiography. Left ventriculography was performed before andafter the last balloon inflation. Written informed consent
was obtained from all patients prior to PMV.

47

Echocardiographic evaluation
All patients underwent comprehensive two-dimensionaland color Doppler echocardiographic evaluations on the
day before and 24 h after undergoing PMV. The morphological features of the mitral valve were assessed, and thetotal echocardiographic score (Wilkins scores) was calculated by adding the scores for leaflet mobility, thickness,
calcification, and subvalvular lesions [12]. MVA was calculated from the Doppler study using the pressure half-time
method and was measured using direct planimetry at theparasternal short-axis view. The mean pressure gradient(MPG) across the mitral valve was assessed using thecontinuous-wave Doppler method. In patients with AF,
measurements were repeated 5 times during different cardiac cycles, and the mean value was used for data analysis.
Pulmonary artery systolic pressure (PASP) was estimatedas the sum of right atrial pressure and the pressure gradient
between the right ventricle and right atrium during systole,
which was calculated using the modified Bernoulli equation. As per the recommendations of the American Societyof Echocardiography [13], right atrial pressure was estimated according to the echocardiographic characteristics of
the inferior cava. After PMV, the extent of the commissurotomy or separation of the commissures, primarily at theparasternal short-axis and the apical two-chamber views,
were assessed along with the development of MR. Color
Doppler flow imaging was performed with multiple
orthogonal parasternal and apical views for diagnosis andquantification of MR after PMV. The severities of MR andtricuspid regurgitation were judged according to theAmerican College of Cardiology/American Heart Association guidelines [14].
Study endpoint and definition of clinical events
Clinical follow-up data were obtained from interviews withpatients, relatives, or attending physicians. The study
endpoint was the cumulative incidence of major cardiovascular adverse events, defined as a composite of all-cause
mortality, hospitalization required for heart failure (HF),
repeated PMV, MVR, and major cerebral vascular accident(CVA) that included ischemic stroke and hemorrhagic
stroke.
Statistical analysis

Fig. 1 Description of the patient population. MS mitral stenosis, MR
mitral regurgitation, PMV percutaneous mitral valvuloplasty, AF
atrial fibrillation, SR sinus rhythm

Continuous data are presented as mean ± standard deviation (SD). Categorical variables were compared between
groups using the Chi-square test or Fisher’s exact test, as
appropriate. Continuous variables were compared between
groups using the Student unpaired t test or the Mann–
Whitney test, according to the distribution. The Kruskal–

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S. Miura et al.

Wallis test was used to compare more than two groups.
Kaplan–Meier analysis was used to determine the eventfree survival rate, and log-rank test was used to analyze
differences in survival rates between the SR and AF
groups. A two-sided probability (p) value \0.05 was considered statistically significant.
The effect of significant clinical factors on clinicalevents was assessed using univariate and multivariate Cox
proportional hazards models. In the predictive analysis,continuous variables were categorized into two subgroups
according to median values. A Cox multivariate analysis
including all variables with p values \0.1 derived from theCox univariate analysis, and proportional assumptions thatwere generally fair, were used to determine the predictive
factors of clinical events. All statistical analyses were
performed using JMP, version 8.0.2 (SAS Institute Inc,
Cary, NC).

Results
Patient characteristics and immediate results
Patients’ baseline characteristics and initial results areshown in Table 1. The average Inoue balloon diameter was
24.6 ± 1.8 mm. The two groups had similar baselinecharacteristics, including age, sex, risk factors foratherosclerosis, and histories of mitral valve intervention
and hospitalization because of HF. Previous major embolic
events were significantly higher in the AF group. The
frequencies of New York Association functional classes(NYHA class) III and IV at baseline were significantly
higher in the AF group compared with those of the SR
Table 1 Comparison ofpatients’ baseline clinicalcharacteristics

group (34 vs. 0 %, p \ 0.01). The immediate hemodynamic and echocardiographic changes are shown in
Table 2. All patients who underwent PMV had an
echocardiographically suitable mitral valve for intervention(echocardiographic score B9). The only significant differences between the groups were observed in left atrium sizeand echocardiographic score. There was no significant
difference between the two groups in post-MVA and postmean mitral MPG, whereas NYHA class post-procedure
was worse in the AF group (p \ 0.01) (Fig. 2).
Long-term outcome of all patients and predictive
factors
All patients completed clinical follow-up with a medianfollow-up of 73 months [interquartile range (IQR):
41–94 months]. The 1, 3, and 6-year rates of event-freesurvival of all patients were 93, 83, and 70 %, respectively.
The 1, 3, and 6-year rates of survival of all patients were 96,
96, and 94 %, respectively (Fig. 3). The univariate predictors of clinical events at follow-up after successful PMV aredetailed in Table 3. Age, sex, heart rhythm, and echocardiographic parameters were tested as a potential predictor of
event-free survival using univariate Cox analysis and significant variables were categorized. None of the procedurerelated variables was predictive. Multivariate analysis
revealed that AF and PASP had an independent value.
Comparison of long-term outcomes between AF
and SR
During the median follow-up period, there were no allcause mortalities in the SR group, whereas 7 patients died
Total (n = 77)

SR (n = 24)

AF (n = 53)

p valueAge (years)

62 ± 961 ± 962 ± 90.64

Sex (female)

54 (71)

19

35

0.25

I–II

59 (77)

24

35

\0.01

III–IV
Previous PMV

18 (23)9 (12)

0
4

18
5

\0.01
0.29

Previous OMC

12 (16)

1

11

0.63

Previous CVA

11 (14)

0

11

0.02

HTN

13 (17)

2

11

0.18

DM

14 (18)

3

11

0.43

CKD

9 (12)

2

7

0.58

History of HF admission

11 (14)

3

8

0.77

NYHA class

Values represent the mean ± SD or n (%)
SR sinus rhythm, AF atrial fibrillation, NYHA class New York Heart Association Functional Class, PMV
percutaneous mitral valvuloplasty, OMC open mitral commissurotomy, CVA cerebral vascular accident,
HTN hypertension, DM diabetes mellitus, CKD chronic kidney disease, HF heart failure

123Impact of preprocedural atrial fibrillation on immediate and long-term outcomes after…
Table 2 Comparison of
echocardiographic
characteristics and immediate
results

Total (n = 77)

49

SR (n = 24)

AF (n = 53)

p value

LVEF (%)

61 ± 1362 ± 1261 ± 14

0.63

LVDD (mm)47 ± 646 ± 648 ± 60.22

LAD (mm)

53 ± 848 ± 655 ± 8\0.001Pre-procedure

1.1 ± 0.2

1.1 ± 0.2

1.1 ± 0.2

0.70

Post-procedure

1.6 ± 0.3

1.6 ± 0.3

1.6 ± 0.2

0.84

MVA (cm2)

Mitral MPG (mmHg)
Pre-procedure

9.0 ± 4.4

8.8 ± 5.8

9.2 ± 4.0

0.78

Post-procedure

5.3 ± 2.6

3.9 ± 1.7

5.7 ± 2.8

0.13

Echocardiographic score

6.6 ± 1.0

6.0 ± 1.4

6.8 ± 0.8

0.01

Baseline MR (III or IV)

1 (1)

0

1

0.68

Baseline TR (III or IV)

8 (10)

2

6

0.99

Baseline PASP (mmHg)

41 ± 1041 ± 1541 ± 80.84

Values represent the mean ± SD or n (%)
SR sinus rhythm, AF atrial fibrillation, LVEF left ventricular ejection fraction, LVDD left ventricular
diastolic dimension, LAD left atrial dimension, MVA mitral valve area, MPG mean pressure gradient, MR
mitral regurgitation, TR tricuspid regurgitation, PASP pulmonary artery systolic pressure

Fig. 2 Functional capacity according to NYHA classes before andafter PMV. NYHA class New York Heart Association functional class,
PMV percutaneous mitral valvuloplasty, AF atrial fibrillation, SR
sinus rhythm *p \ 0.01

occurred in both the groups during the median follow-up
period are listed in Table 4. There were more mortalities
and more interventions in the AF group, although the difference was not statistically significant, except for mitralvalve surgery. In the present study, we added major CVA
as a clinical event. The estimated actuarial 6-year rates of
CVA-free survival were 95 % in the SR group and 89 % in
the AF group. The incidence of major CVA tended to be
more frequent in the AF group, although the difference was
not statistically significant (p = 0.51). In addition, 9 out of
24 patients in the SR group newly developed chronic or
persistent AF within the follow-up period, but there was no
significant difference in both the survival and event-freesurvival rates between the new-onset AF group (n = 9) andthe rest of the SR group (n = 15) (p = 1.0; p = 0.25,
respectively).

Discussion
in the AF group due to the following reasons: HF (2), acute
myocardial infarction (1), bacterial pneumonia (1), gastrointestinal bleeding (1), liver cirrhosis (1), and sudden
death (1). Survival rates in the AF group were 94, 94, and
92 % at 1, 3, and 6 years. AF group in comparison with SR
group demonstrated a trend toward a higher survival rate
(p = 0.099) that was not statistically significant. These
results are shown in the Kaplan–Meier plots in Fig. 4a. The
1-, 3-, and 6-year rates of event-free survival between thetwo groups were (SR vs. AF) 100 vs. 91 %, 100 vs. 76 %,and 95 vs. 59 %, respectively. The event rate was significantly higher in the AF group compared with that of the SR
group (p = 0.016) (Fig. 4b). The clinical events that

AF adversely affects immediate and long-term results of
PMV for significant MS [15, 16]. A major feature of thepresent study is that patients with a history of PMV andopen mitral commissurotomy were included and patientswith unfavorable mitral valve morphology for PMV(echocardiographic score C10) were excluded. Adverse
clinical events included HF requiring hospitalization, major
CVA, mortality, and repeated PMV and MVR. In such aclinical setting, our present study provides beneficial
information related to daily clinical practice, because
between the two groups with similar baseline MS, patientsin preprocedural AF had similar immediate optimal results

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S. Miura et al.

Fig. 3 Kaplan–Meier curves of survival and event-free survival after
successful PMV (n = 77). The clinical events were defined as allcause mortality, hospitalization for HF, repeated PMV, MVR, andTable 3 Univariate andmultivariate Cox regression
analysis predicting clinicalevents after successful PMV

major CVA. HF heart failure, PMV percutaneous mitral valvuloplasty, MVR mitral valve replacement, CVA cerebral vascular
accident

Variables

Univariate

Age (C62 years)a

Multivariate

HR

95 % CIp valueHR

95 % CIp value

2.11

1.03–4.59

0.041

1.81

0.87–3.96

0.109

1.04–9.36

0.039

1.18–5.47

0.017

Women

0.77

0.37–1.73

0.514

–

NYHA class (III–IV)

1.34

0.58–2.90

0.489

–

Atrial fibrillation

3.33

1.29–11.27

0.010

2.73

LAD (C52 mm)a1.50

0.73–3.07

0.267

–

Pre-procedural MVA (B1.1 cm2)a0.84

0.39–1.73

0.647

–

2 a

Post-procedural MVA (B1.6 cm )1.09

0.53–2.22

0.815

–

PASP (C39 mmHg)a3.05

1.42–6.42

0.004

2.57

Echocardiographic score (C8 points)

3.21

0.50–11.44

0.181

PMV percutaneous mitral valvuloplasty, NYHA class New York Heart Association Functional Class, LAD
left atrial diameter, MVA mitral valve area, PASP pulmonary artery systolic pressure, HR hazard ratio, CI
confidence intervalaContinuous variables were categorized into two subgroups according to median values

compared with those in SR. However, AF was associatedwith shorter long-term and event-free survival.
During clinical follow-up after PMV, the actuarial
6-year rates of survival without any-cause mortality, any
subsequent intervention on the mitral valve, and any CVA
were 70 % after successful PMV. Interestingly, the survival rate of all patients during the follow-up period was[90 %, which seems acceptable relative to those reported
by others [17, 18]. However, approximately 40 % of all
patients developed some clinical event within 7 years after

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successful PMV (Fig. 3). In our population, clinical outcome was strongly related to the baseline characteristics ofthe patients, particularly preprocedural AF and PASP,
rather than post-procedural immediate results or baseline
severity of MS. These data suggest that development of aclinical event was not always related to progression ofseverity of MS.
The incidence of AF in patients with MS is approximately 40 % [19]. AF associated with rheumatic heartdisease differs in pathophysiology from that of AF in non-Impact of preprocedural atrial fibrillation on immediate and long-term outcomes after…

51

Fig. 4 Kaplan–Meier survival
curves free from a all-cause
mortality, b clinical events in
SR (n = 24) and AF (n = 53)
groups after successful PMV.
PMV percutaneous mitralvalvuloplasty, SR sinus rhythm,
AF atrial fibrillation

Table 4 Clinical events at themedian follow-up

Clinical events

Total (n = 77)

SR (n = 24)

AF (n = 53)

p valueAll-cause mortality

7 (9 %)

0 (0 %)

7 (13 %)

0.06

HF for admission
Mitral valve replacement

9 (12 %)
14 (18 %)

1 (4 %)
1 (4 %)

8 (15 %)
13 (25 %)

0.16
0.03

Repeated PMV

5 (6 %)

1 (4 %)

4 (8 %)

0.50

Major CVA

7 (9 %)

1 (4 %)

6 (11 %)

0.29

Data are n (%)
SR sinus rhythm, AF atrial fibrillation, HF heart failure, PMV percutaneous mitral valvuloplasty, CVA
cerebral vascular accident

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rheumatic disease. Age is a predominant factor in thedevelopment of AF, and left atrial enlargement may be theresult, rather than the cause, of AF. The severity of MS is
not invariably related to the incidence of AF [20], which isconsistent with our finding that there was no difference
between the two groups in MVA and MPG at baseline andafter the procedure. Fawzy et al. reported that PMV inpatients with AF achieved an inferior immediate result thatwas reflected by a lower success rate and a smaller postPMV MVA [15, 16]. These different results may be
explained by our selection of patients with valve morphology suitable for PMV. In the studies cited, echocardiographic scores of patients with AF were worse
compared with their population selected by Fawzy et al. atbaseline. Further, it is still unclear that AF has an adverse
effect on the technical success of PMV. Therefore, 7
patients with major complications after PMV were excluded from our population.
The AF group showed higher preprocedural NYHA
class, larger left atrial size, and higher echocardiographic
score compared with those of the SR group. These findings
indicate that left atrial remodeling progressed in the AF
group compared with the SR group, even in those withsimilar severities of MS. Other study supports this idea,
demonstrating that left atrial diameter independently predicted incidents of cardiovascular events [21]. According
to the report investigated by Bouleti et al. [22], significant
interaction between rhythm and NYHA class was observed
only in patients with AF. Such patients with ‘‘advanced’’MS may be significantly associated with a higher NYHA
class and higher incidence of clinical events. Peter et al.
[20] showed that hemodynamic measurements are notsignificantly different between patients with SR and thosewith chronic AF, with the single exception of lower cardiac
outputs of patients with established AF. A low output state
may be related to worse symptoms and functional capacityin patients with MS accompanied by AF compared withpatients with SR.
Here, we demonstrate that the survival of patients withpreprocedural AF was shorter compared with those withpreprocedural SR. No patient with SR died after successful
PMV during our study. These results are somewhat better
compared with those of a previous report with survival
rates of 89 % for the SR group and 68 % for the AF groupwith a mean follow-up of 5 years [16]. This difference is
may be explained by the suitability of our population forPMV (echocardiographic score B9), as only those patients
who achieved primary success were enrolled in our study.
In our institute, almost all patients with echocardiographically unfavorable mitral valve for PMV and major complications after PMV were referred to surgical options. The
incidences of MVR and repeated PMV were higher in the
AF group compared with those of the SR group. Therefore,

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S. Miura et al.

these data suggest that the recurrence rate of MS was
higher in the AF group, even if the immediate results weresimilar to those of the SR group.
Advanced age, baseline NYHA class IV, high echocardiographic score (C9), history of surgical commissurotomy, and mitral valve calcification are associated withimproved suboptimal immediate outcomes and fewer longterm clinical events after PMV [23]. However, theseparameters were not statistically significant in our study.
The strong association between age and AF in MS suggeststhat the structural changes in the atrial myocardium thatpredispose to AF are time-dependent. Maatouk et al.
showed that AF was an independent predictor of overallmortality and combined events. Their study population is
worth noting, because patients with AF were much older
compared with those with SR (44 ± 12 vs. 30 ± 13 years)[18]. On the contrary, Leon et al. reached at a conclusionthat the presence of AF alone does not influence the longterm outcome, although there were significant differences
at baseline in both groups (62 ± 12 years for AF vs.
48 ± 14 years for SR) [16]. Notably, the mean age of ourpatients in both groups was 62 years, and 67 % still had AF
at baseline. A simple comparison between these studies isobviously not possible due to differences in patient characteristics. However, we speculate that AF may have amore adverse effect on long-term outcome of older
patients. Further studies are required to clarify the effect of
PMV on long-term outcomes according to age.
Early PMV has not been shown to be universally successful in preventing AF. In the present study, nearly 40 %of the SR group presented with AF at their final visit after
successful PMV, which may be explained by the complex
nature of AF in MS. Therefore, the optimal timing of PMV
remains controversial for asymptomatic patients with significant MS and SR. Nonetheless, our data indicate thepossibility that performing PMV before the onset of AF
provides long-term clinical benefit through a complex
mechanism other than maintaining SR. Moreover, patientswith SR are associated with fewer symptoms comparedwith those with AF, as demonstrated in our data.
However, early intervention should be considered for
SR patients with moderate MS and minimal symptoms,
instead of watchful waiting for worsening of symptoms ordeveloping a new-onset AF. A study that supports theserecommendations found that in asymptomatic patientswith moderate MS and favorable valve morphology, theestimated actuarial 11-year event-free survival rate was
89 % in the PMV group and 69 % in the conventional
management group (p \ 0.001), suggesting that the clinical benefits of early PMV may outweigh the risk associated with early intervention [24]. Prospective
randomized trials are required to confirm the efficacy ofearly PMV.

Impact of preprocedural atrial fibrillation on immediate and long-term outcomes after…

Study limitations
There were a few limitations in this study. First, this is aretrospective study of the records of a small number ofpatients from a single institution. Similar to otherdeveloped countries, the number of patients in Japan
with MS requiring PMV is decreasing, along with the
decline of the incidence of rheumatic heart disease [25].
In contrast, there are an increasing number of patients
who require repeat treatment after undergoing PMV or
surgical mitral commissurotomy. Therefore, we did not
exclude such patients from our study. Second, we
demonstrated that 59 % of the SR group had AF at the
final visit after successful PMV. Further, we did notconduct a systematic study of the differences between
persistent SR patients and those with new-onset postprocedural patients with AF, although the latter havesome associations with prognosis or clinical events.
However, defining patients with consistent SR is nottrivial, because they can present with subclinical, transient AF. Further prospective randomized studies are
required to confirm our results.

Conclusions
PMV is a useful palliative procedure with excellent longterm results. Patients with AF were significantly associatedwith worse symptoms and higher event rates after undergoing successful PMV compared with those with SR.
Patients with AF should be followed carefully for an
extended time after successful PMV. Moreover, appropriate management of AF in patients undergoing PMV for MS
may represent an important next step to alleviate symptoms
or improve clinical outcomes.
Compliance with ethical standards
This study was approved by our Institutional Review Board. Written
informed consent was obtained from all patients prior to PMV.
Conflict of interest None.
Open Access This article is distributed under the terms of theCreative Commons Attribution 4.0 International License (http://crea
tivecommons.org/licenses/by/4.0/), which permits unrestricted use,
distribution, and reproduction in any medium, provided you give
appropriate credit to the original author(s) and the source, provide alink to the Creative Commons license, and indicate if changes were
made.

References
1. Inoue K, Owaki T, Nakamura T, Kitamura F, Miyamoto N.
Clinical application of transvenous mitral commissurotomy by a53

new balloon catheter. J Thorac Cardiovasc Surg.
1984;87:394–402.
2. Lock JE, Khalilullah M, Shrivastava S, Bahl V, Keane JF. Percutaneous catheter commissurotomy in rheumatic mitral stenosis.
N Engl J Med. 1985;313:1515–8.
3. Nobuyoshi M, Hamasaki N, Kimura T, Nosaka H, Yokoi H,
Yasumoto H, et al. Indications, complications, and short-termclinical outcome of percutaneous transvenous mitral commissurotomy. Circulation. 1989;80:782–92.
4. Dean LS, Mickel M, Bonan R, Holmes DR Jr, O’Neill WW,
Palacios IF, et al. Four-year follow-up of patients undergoing
percutaneous balloon mitral commissurotomy. A report from the
National Heart, Lung, and Blood Institute Balloon Valvuloplasty
Registry. J Am Coll Cardiol. 1996;28:1452–7.
5. Olivier C. Rheumatic fever–is it still a problem? J Antimicrob
Chemother. 2000;45(Suppl):13–21.
6. Fawzy ME, Shoukri M, Al Buraiki J, Hassan W, El Widaal H,
Kharabsheh S, et al. Seventeen years’ clinical and echocardiographic follow up of mitral balloon valvuloplasty in 520 patients,
and predictors of long-term outcome. J Heart Valve Dis.
2007;16:454–60.
7. Fawzy ME, Shoukri M, Hassan W, Nambiar V, Stefadouros M,
Canver CC. The impact of mitral valve morphology on the longterm outcome of mitral balloon valvuloplasty. Catheter Cardiovasc Interv. 2007;69:40–6.
8. Zhang HP, Allen JW, Lau FY, Ruiz CE. Immediate and lateoutcome of percutaneous balloon mitral valvotomy in patientswith significantly calcified valves. Am Heart J. 1995;129:501–6.
9. Post JR, Feldman T, Isner J, Herrmann HC. Inoue balloon mitralvalvotomy in patients with severe valvular and subvalvular
deformity. J Am Coll Cardiol. 1995;25:1129–36.
10. Hildick-Smith DJ, Taylor GJ, Shapiro LM. Inoue balloon mitralvalvuloplasty: long-term clinical and echocardiographic followup of a predominantly unfavourable population. Eur Heart J.
2000;21:1690–7.
11. Pavlides GS, Nahhas GT, London J, Gangadharan C, Troszak E,
Barth-Jones D, et al. Predictors of long-term event-free survival
after percutaneous balloon mitral valvuloplasty. Am J Cardiol.
1997;79:1370–4.
12. Wilkins GT, Weyman AE, Abascal VM, Block PC, Palacios IF.
Percutaneous balloon dilatation of the mitral valve: an analysis ofechocardiographic variables related to outcome and the mechanism of dilatation. Br Heart J. 1988;60:299–308.
13. Rudski LG, Lai WW, Afilalo J, Hua L, Handschumacher MD,
Chandrasekaran K, et al. Guidelines for the echocardiographic
assessment of the right heart in adults: a report from the American Society of Echocardiography endorsed by the European
Association of Echocardiography, a registered branch of theEuropean Society of Cardiology, and the Canadian Society of
Echocardiography. J Am Soc Echocardiogr. 2010;23:685–713(quiz 86–8).
14. Bonow RO, Carabello BA, Kanu C, de Leon AC Jr, Faxon DP,
Freed MD, et al. ACC/AHA 2006 guidelines for the managementof patients with valvular heart disease: a report of the American
College of Cardiology/American Heart Association Task Forceon Practice Guidelines (writing committee to revise the 1998
Guidelines for the Management of Patients With Valvular Heart
Disease): developed in collaboration with the Society of Cardiovascular Anesthesiologists: endorsed by the Society for Cardiovascular Angiography and Interventions and the Society ofThoracic Surgeons. Circulation. 2006;114:e84–231.
15. Fawzy ME, Shoukri M, Osman A, El Amraoui S, Shah S,
Nowayhed O, et al. Impact of atrial fibrillation on immediate andlong-term results of mitral balloon valvuloplasty in 531 consecutive patients. J Heart Valve Dis. 2008;17:141–8.

123

54
16. Leon MN, Harrell LC, Simosa HF, Mahdi NA, Pathan A, LopezCuellar J, et al. Mitral balloon valvotomy for patients with mitral
stenosis in atrial fibrillation: immediate and long-term results.
J Am Coll Cardiol. 1999;34:1145–52.
17. Iung B, Garbarz E, Michaud P, Helou S, Farah B, Berdah P, et al.
Late results of percutaneous mitral commissurotomy in a series of1024 patients. Analysis of late clinical deterioration: frequency,
anatomic findings, and predictive factors. Circulation.
1999;99:3272–8.
18. Maatouk F, Betbout F, Ben-Farhat M, Addad F, Gamra H, BenHamda K, et al. Balloon mitral commissurotomy for patients withmitral stenosis in atrial fibrillation: ten-year clinical andechocardiographic actuarial results. J Heart Valve Dis.
2005;14:727–34.
19. Nobuyoshi M, Arita T, Shirai S, Hamasaki N, Yokoi H, Iwabuchi
M, et al. Percutaneous balloon mitral valvuloplasty: a review.
Circulation. 2009;119:e211–9.
20. Probst P, Goldschlager N, Selzer A. Left atrial size and atrial
fibrillation in mitral stenosis. Factors influencing their relationship. Circulation. 1973;48:1282–7.

123

S. Miura et al.
21. Kizer JR, Bella JN, Palmieri V, Liu JE, Best LG, Lee ET, et al.
Left atrial diameter as an independent predictor of first clinicalcardiovascular events in middle-aged and elderly adults: theStrong Heart Study (SHS). Am Heart J. 2006;151:412–8.
22. Bouleti C, Iung B, Laouenan C, Himbert D, Brochet E, MessikaZeitoun D, et al. Late results of percutaneous mitral commissurotomy up to 20 years: development and validation of a risk
score predicting late functional results from a series of 912
patients. Circulation. 2012;125:2119–27.
23. Palacios IF. Percutaneous mitral balloon valvotomy for patientswith mitral stenosis. Curr Opin Cardiol. 1994;9:164–75.
24. Kang DH, Lee CH, Kim DH, Yun SC, Song JM, Lee CW, et al.
Early percutaneous mitral commissurotomy vs. conventional
management in asymptomatic moderate mitral stenosis. Eur
Heart J. 2012;33:1511–7.
25. Leiner S. Surveillance for rheumatic fever. N Engl J Med.
1996;334:273–4.