Prognostic Role of Myocardial Blood Flow Impairment in Idiopathic Left Ventricular Dysfunction

Abstract

Background-Depressed myocardial blood flow (MBF) has been reported in dilated cardiomyopathy. The aim of this study was to investigate whether MBF impairment is an independent predictor of prognosis in patients with idiopathic left ventricular (LV) dysfunction. Methods and Results-Sixty-seven patients (52 male, mean age 52Ϯ12 years) with different degrees of idiopathic LV systolic dysfunction (average LV ejection fraction, 0.34Ϯ0.10; range, 0.07 to 0.49) were prospectively enrolled. Thirty-four subjects (51%) had no history of heart failure symptoms at enrollment (NYHA class I). All patients underwent clinical and functional evaluation and a PET study to measure absolute MBF at rest and after intravenous dipyridamole. During a mean follow-up of 45Ϯ37 months, 24 patients had major cardiac events, including cardiac death in 8 and development or progression of heart failure in 16 patients. Multivariate regression analysis (Cox proportional hazards model) revealed heart rate ( 2 11.06, PϽ0.001), LV end-diastolic dimension ( 2 11.73, PϽ0.001), and dipyridamole MBF ( 2 11.04, PϽ0.001) as independent predictors of subsequent cardiac events. Dipyridamole MBF Յ1.36 mL ⅐ min Ϫ1 ⅐ g Ϫ1 was associated with an increase in the relative risk of death, development, or progression of heart failure of 3.5 times over other more common clinical and functional variables. Conclusions-The present study demonstrates that severely depressed MBF is a predictor of poor prognosis in patients with idiopathic LV dysfunction independently of the degree of LV functional impairment and of the presence of overt heart failure.

Myocardial Perfusion Is Impaired and Relates to Cardiac Dysfunction in Patients With Atrial Fibrillation Both Before and After Successful Catheter Ablation

“…This is not surprising as in patients with hypertrophic or dilated cardiomyopathy (and no epicardial coronary artery disease),20, 21 stress MBF has been shown to be superior to perfusion reserve for uncovering coronary microvascular dysfunction and predicting adverse cardiac events 22…”

Serum markers of angiogenesis and myocardial ultrasonic tissue characterization in patients with dilated cardiomyopathy

“…Tissue ischemia occurs within the myocardium in DCM, possibly due to a decreased supply caused by microvascular structural and functional abnormalities. Indeed, recent studies have shown that the reduction in myocardial blood flow and volume have been observed in patients with DCM [29,30]. Therefore, it is very likely that the increased serum activity of VEGF in patients with DCM is involved in myocardial perfusion abnormalities.…”

“…CV-IB can be of value in quantifying regional differences in myocardial contractile performance in DCM. Moreover, it is known that the reduction in myocardial blood flow influences attenuation and scattering of myocardial tissue, and could be associated with the deterioration of LV systolic function [29,30]. Accordingly, the increase in serum VEGF may be closely associated with the impaired intrinsic myocardial contractile performance caused by myocardial microvascular abnormalities and myocardial interstitial fibrosis in DCM.…”

The imbalance between coronary reserve and wall stress explains the severity of ventricular dysfunction in hypertension

“…The development of impaired coronary reserve has been well recognized in patients with idiopathic dilated cardiomyopathy and implies a poorer prognosis in the long term. 32 In HTN, microvessel disease might be a marker of concurrent idiopathic dilated cardiomyopathy.…”