Background The identification of responders remains challenging in cardiac resynchronization therapy (CRT). Pressure-volume relationship (PVR) is a method to evaluate left ventricular myocardial contractility during stress. The aim of the study was to assess the role of PVR to identify responders to CRT. Methods Seventy-two patients (57% with ischemic etiology) referred to CRT: ejection fraction <= 35%, New York Heart Association >= III and QRS duration >= 120 milliseconds, underwent dobutamine stress echocardiography (up to 40 mu g/kg per minute). PVR was defined as systolic cuff pressure/end-systolic volume index difference between rest-peak dobutamine stress echocardiography. Responders were identified by clinical and/or echocardiographic (end-systolic volume decrease >= 15%) follow-up criteria. We divided retrospectively the patient population into 2 groups, accordingly to the presence of myocardial contractile reserve that was set at the value of PVR (0.72 mm Hg/mL per square meter) obtained by a receiver operating characteristic analysis. Results During a median follow-up of 12 months, 8 patients (11%) died. Patients with lower PVR, showed higher brain natriuretic peptide levels (853 +/- 1211 vs 342 +/- 239, P=.044) larger left ventricular end-diastolic (196 +/- 82 mL vs 152 +/- 39 mL, P=.005) and end-systolic (147 +/- 66 vs 112 +/- 30 mL, P=.006) volumes. Intraventricular dyssynchrony was similar in the 2 groups (88 +/- 45 vs 70 +/- 32 milliseconds, P=.175). Patients with higher PVR presented a larger incidence of clinical (86% vs 46% P<.001), and echocardiographic responders to CRT (79% vs 40%, P=.002). Event-free survival was significantly better in patients with higher PVR (log rank = 5.78, P=.01). Conclusion Patients with preserved contractility, assessed by PVR during stress echocardiography show a favor clinical outcome and left ventricular reverse remodeling after CRT. In particular, PVR may have a significant clinical role in patients undergoing CRT, providing critical information for risk stratification. (Am Heart J 2010;160:906-14.)
Clinical and prognostic role of pressure-volume relationship in the identification of responders to cardiac resynchronization therapy
Citro R;
2010-01-01
Abstract
Background The identification of responders remains challenging in cardiac resynchronization therapy (CRT). Pressure-volume relationship (PVR) is a method to evaluate left ventricular myocardial contractility during stress. The aim of the study was to assess the role of PVR to identify responders to CRT. Methods Seventy-two patients (57% with ischemic etiology) referred to CRT: ejection fraction <= 35%, New York Heart Association >= III and QRS duration >= 120 milliseconds, underwent dobutamine stress echocardiography (up to 40 mu g/kg per minute). PVR was defined as systolic cuff pressure/end-systolic volume index difference between rest-peak dobutamine stress echocardiography. Responders were identified by clinical and/or echocardiographic (end-systolic volume decrease >= 15%) follow-up criteria. We divided retrospectively the patient population into 2 groups, accordingly to the presence of myocardial contractile reserve that was set at the value of PVR (0.72 mm Hg/mL per square meter) obtained by a receiver operating characteristic analysis. Results During a median follow-up of 12 months, 8 patients (11%) died. Patients with lower PVR, showed higher brain natriuretic peptide levels (853 +/- 1211 vs 342 +/- 239, P=.044) larger left ventricular end-diastolic (196 +/- 82 mL vs 152 +/- 39 mL, P=.005) and end-systolic (147 +/- 66 vs 112 +/- 30 mL, P=.006) volumes. Intraventricular dyssynchrony was similar in the 2 groups (88 +/- 45 vs 70 +/- 32 milliseconds, P=.175). Patients with higher PVR presented a larger incidence of clinical (86% vs 46% P<.001), and echocardiographic responders to CRT (79% vs 40%, P=.002). Event-free survival was significantly better in patients with higher PVR (log rank = 5.78, P=.01). Conclusion Patients with preserved contractility, assessed by PVR during stress echocardiography show a favor clinical outcome and left ventricular reverse remodeling after CRT. In particular, PVR may have a significant clinical role in patients undergoing CRT, providing critical information for risk stratification. (Am Heart J 2010;160:906-14.)I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
