Prognostic implications of structural heart disease and premature ventricular contractions in recovery of exercise

Abstract

Background: Premature ventricular contractions (PVCs) during the recovery of exercise stress testing are associated with increased cardiovascular mortality, but the cause remains unknown. We aimed to evaluate the association of PVCs during recovery with abnormalities on echocardiography, and to evaluate their combined prognostic performance. Methods: Echocardiographic abnormalities (reduced left ventricular (LV) ejection fraction, valvular heart disease, LV dilatation, LV hypertrophy, or increased filling pressures) and the presence of PVCs during recovery (≥1/min) were identified among patients having undergone resting echocardiography within median [interquartile range] 0 [0-2] days of an exercise stress test. The association between such changes and cardiovascular mortality was analyzed using Cox regression adjusted for age, sex, clinical and exercise variables. Results: Among included patients (n=3,106, 219 events, 7.9 [5.4-11.1] years follow-up), PVCs during recovery was found in 1,327 (43%) patients, among which prevalence of echocardiographic abnormalities was increased (58% vs. 43%, p<0.001). Overall, PVCs during recovery was associated with increased cardiovascular mortality (adjusted hazard ratio (HR) [95% confidence interval] 1.6 [1.2-2.1], p<0.001). When combined with echocardiographic abnormalities, PVCs during recovery was only associated with increased risk when such were present (adjusted HR 3.3 [2.0-5.4], p<0.001), and not when absent (adjusted HR 1.4 [0.7-2.6], p=0.26), in reference to those with neither. Conclusion: PVCs during recovery was associated with increased prevalence of echocardiographic abnormalities. Increased risk of cardiovascular mortality was observed only for subjects with PVCs if concomitant echocardiographic abnormalities were present. This provides a structural explanation for the increased long-term cardiovascular risk among patients with PVCs during recovery.