Long-term prognosis of tachycardiomyopathy without underlying heart disease
Authors: Stronati G , Urbinati A , Principi S , Silenzi M , Ciliberti G , Barbarossa A , Compagnucci P , Casella M , Dello Russo A , Guerra F 
Published: October 2021

Abstract

Background
Tachycardiomyopathy (TCM) is a reversible cause of left ventricular dysfunction, secondary to rapid and/or asynchronous, irregular myocardial contraction. Two categories of the disease have been described: arrhythmia-induced TCM (pure TCM), where the arrhythmia is the sole reason for the dysfunction, and arrhythmia-mediated TCM (impure TCM), where the arrhythmia can exacerbate or worsen heart failure (HF) or an underlying heart disease. Pure TCM has already been described as affecting almost 1 out of 10 patients admitted for acute HF-like symptoms. On the other side, acute HF leads to a chronic irreversible condition which tends to worsen over time and is burdened by a high rate of complications.

Purpose
The aim of our study was to compare pure TCM and de novo acute HF patients (including all forms of structural heart disease) in terms of mortality and cardiovascular (CV)-related hospitalizations.

Methods
Prospective, observational study enrolling all consecutive patients with a confirmed diagnosis of TCM and all patients admitted for de novo acute HF. The TCM diagnosis was suspected in all patients admitted for HF-related symptoms, an ejection fraction &lt;50% with concomitant persistent atrial or ventricular arrhythmia, and confirmed after clinical and echocardiographic recovery. Acute HF diagnosis was made in all patients with an ejection fraction &lt;50%, new HF-like symptoms, diagnosis of structural heart disease and no evidence of clinical or echocardiographic recovery. For each patient, all-cause death and CV-related hospitalizations were recorded. Propensity score matching was used in order to compare the two populations through sensitivity analysis.

Results
One-hundred-and-ten patients with TCM (61.8% males, 68±13 years old) were propensity matched with a control population of patients with HF and structural heart disease (76.6% males, 71±15 years old, 75% ischemic heart disease). After a median follow-up of 5.1 years (1st-3rd quartile 2.6–7.0 years) TCM patients showed an overall higher estimate of survival when compared to HF patients (78% vs. 58%; p=0.031; figure 1A) but a lower estimate of time free from CV-related hospitalization (31% vs. 57%, p=0.014; figure 1B). TCM patients got most often readmitted for AF-related elective procedures (60.8% of all hospitalizations), TCM recurrence (13.7%) and elective coronary angiography (5.9%). On the other hand, HF patients got readmitted for HF worsening (40.9%), cardiac or vascular surgery (22.7%) and elective coronary angiography (9.1%). Propensity-score matched analysis confirmed the results for all-cause death (81% vs. 49%; p=0.006) and CV-related hospitalizations (29% vs. 54%; p=0.007).

Conclusions
TCM is associated with a better survival when compared to de novo acute HF, even after propensity score adjustment. On the other hand, patients with TCM got readmitted more frequently, requiring more often elective procedures in order to control the triggering arrhythmia.

Funding Acknowledgement
Type of funding sources: None.