The additive prognostic value of restrictive pattern and dipyridamole‐induced contractile reserve in idiopathic dilated cardiomyopathy

Abstract

Diastolic dysfunction and lack of contractile reserve are unfavorable prognostic predictors in patients with dilated cardiomyopathy (DCM). This study aims to assess whether diastolic dysfunction and lack of dipyridamole-induced contractile reserve were additive predictors of poor outcome in patients with DCM. A total of 116 patients with DCM and ejection fraction (EF<35%) were studied by dipyridamole echo (0.84 mg/kg over 10 min). At rest, a restrictive filling pattern was defined as: E/A ratio >2 and an E-wave deceleration time of <140 ms on transmitral flow velocity profile. Rest wall motion score index (WMSI) was 2.2+/-0.3 and decreased to 1.9+/-0.41 after dipyridamole (p<0.001). During follow-up (median 26.5 months), 22 cardiac deaths occurred. At multivariate analysis, dipyridamole-induced contractile reserve yielded significant incremental prognostic value (RR=0.275, p<0.006) over NYHA class (RR=1.971, p<0.03), angiotensin-converting enzyme inhibitor therapy (RR=0.173, p<0.001), and left ventricular end-diastolic diameter (RR=1.131, p<0.001). The worst prognostic combination was the presence of restrictive pattern at rest and the absence of contractile reserve (deltaWMSI<0.15). In patients with DCM, the ominous combination of restrictive transmitral flow pattern and lack of contractile reserve during dipyridamole stress predicts an unfavourable outcome.