Abstract P278: Safety of Symptom-Limited Cardiopulmonary Exercise Testing in Asymptomatic Patients With Aortic Stenosis
Authors: Dhoble Abhijeet , Kopecky Stephen L , Thomas Randal J , Squires Ray W , Gau Gerald T , Sarano Maurice E , Allison Thomas G 
Published: July 2021

Background:
We conducted this study to assess the safety of symptom-limited cardiopulmonary exercise testing (CPX) in patients with varying severity of aortic stenosis (AS). We hypothesized that exercise testing would be safe, as defined by a rates for all-cause death of <0.01% and rate of nonfatal major cardiovascular (CV) events <0.1% within 24 hours of CPX. Secondary purpose of this study was to determine the frequency of complications during CPX.

Methods:
This cohort study was carried out with 308 consecutive patients with varying degree of AS (as determined by standard echocardiographic criteria) with no or equivocal symptoms who were referred for clinically indicated cardiopulmonary testing between 1994 and 2009. We did not include patients with pending or completed heart transplant, or ventricular assist device implantation. These patients underwent standard symptom limited CPX, and continuous monitoring of heart rate, blood pressure, and electrocardiogram was performed. Complications recorded included death, non-fatal major CV events (cardiac arrest, symptomatic and sustained ventricular or atrial tachycardia, and syncope), and minor events such as hypotension, non-sustained atrial and ventricular arrhythmias, positive exercise ECG and anginal pain.

Results:
The mean age of patients was 66 ± 14 years, and 252 (82%) were males. The number of patients with mild, moderate and severe AS were 44 (14%), 138 (49%), and 126 (41%) respectively. No death or major CV event occurred during or within 24 hours of CPX. Eleven patients developed supraventricular arrhythmias without compromising hemodynamic status, and one had asymptomatic non-sustained ventricular tachycardia. Detailed description of complications is presented in the
Table 1
.

Conclusion:
Our results show that symptom-limited CPX is safe among AS patients with no or equivocal symptoms based on no deaths or major CV events in our cohort. Minor complications occurred in 110 patients (36%).

Table 1

Mild AS (n=44)
Moderate AS (n=138)
Severe AS (n=126)

Age
61.7 ± 15.3
66.5 ± 13.86
67.89 ± 12.74

Males
36 (81%)
128 (83%)
96 (85%)

Test protocol
O2 protocol
39 (86%)
123 (89%)
104 (82%)

Other
5
15
22

Reason for termination
Symptom-limited
41 (93%)
114 (82%)
96 (76%)

Other
3
24
30

Chest pain
None
41 (93%)
122 (88%)
117 (93%)

Non-cardiac
0
2
0

Non-anginal
0
2
0

Anginal
2
14
9

Treadmill ECG interpretation
Negative
27 (61%)
67 (49%)
45 (37%)

Non-diagnostic
14
48
58

Positive
3
23
23

Ventricular arrhythmia
None
42 (95%)
134 (97%)
122 (97%)

3-5 beats VT
2
3
4

NSVT
0
1
0

Supraventricular arrhythmia
None
42 (95%)
135 (97%)
120 (95%)

SVT ≤ 30 sec
2
3
4

SVT > 30 sec
0
0
1

Afib
0
0
1

BP response
Normal
41 (93%)
117 (85%)
93 (74%)

Hypotensive
3
21
33

AS = Aortic Stenosis, ECG = Electrocardiogram, VT = Ventricular tachycardia, NSVT = Non-sustained ventricular tachycardia, SVT = Supraventricular tachycardia, Afib = Atrial fibrillation, BP = Blood pressure