Severe microvascular dysfunction (Dip-MBF <1.1 ml/min/g) independently predicted long-term left ventricular systolic dysfunction in hypertrophic cardiomyopathy (relative hazard 7.5; p=0.038).
Cohort (n=51)
Does severe coronary microvascular dysfunction predict the development of left ventricular remodeling and systolic dysfunction in patients with hypertrophic cardiomyopathy?
Severe coronary microvascular dysfunction assessed by PET is a strong independent predictor of long-term adverse left ventricular remodeling and systolic dysfunction in patients with hypertrophic cardiomyopathy.
Effect estimate: relative hazard 7.5
p-value: p=0.038
OBJECTIVES: This study sought to evaluate whether the entity of microvascular dysfunction, assessed by positron emission tomography (PET), predicts the long-term development of left ventricular (LV) remodeling and systolic dysfunction in hypertrophic cardiomyopathy (HCM). BACKGROUND: A subgroup of patients with HCM developed LV dilation and systolic impairment. A causal role of coronary microvascular dysfunction has been suggested as the underlying pathophysiological mechanism. METHODS: Fifty-one patients (New York Heart Association functional class I to II) were followed up for 8.1 +/- 2.1 years after measurement of resting and dipyridamole (Dip) myocardial blood flow (MBF). Left ventricular systolic dysfunction was defined as an ejection fraction (LVEF) 5 mm) during follow-up. These 11 patients showed lower Dip-MBF than the 40 with preserved LV function (1.04 +/- 0.38 ml/min/g vs. 1.63 +/- 0.71 ml/min/g, respectively; p = 0.001); Dip-MBF was particularly blunted in five patients with clinical progression to severe heart failure symptoms or death (Dip-MBF 0.89 +/- 0.15 ml/min/g). At multivariate analysis, the two independent predictors of systolic dysfunction were Dip-MBF in the lowest tertile (45 mm; relative hazard, 12.3; p = 0.031). CONCLUSIONS: Severe microvascular dysfunction is a potent long-term predictor of adverse LV remodeling and systolic dysfunction in HCM. Our findings indicate microvascular dysfunction as a potential target for prevention of disease progression and heart failure in HCM.
Olivotto et al. (2006) conducted a cohort in Hypertrophic cardiomyopathy (n=51). Dipyridamole myocardial blood flow (Dip-MBF) was evaluated on Left ventricular systolic dysfunction (LVEF <50%) (relative hazard 7.5, p=0.038). Severe microvascular dysfunction (Dip-MBF <1.1 ml/min/g) independently predicted long-term left ventricular systolic dysfunction in hypertrophic cardiomyopathy (relative hazard 7.5; p=0.038).