Abnormal left ventricular subendocardial perfusion and diastolic function in women with obesity and heart failure and preserved ejection fraction

Abstract

Purpose – Coronary microvascular dysfunction (CMD) is common in patients with heart failure with preserved ejection fraction (HFpEF) and obesity. Stress cardiovascular magnetic resonance (CMR) has been proposed as a non-invasive tool for detection of CMD. The aim of this study was to determine relationship between CMD and diastolic function in patients with HFpEF using a novel CMR technique. Methods – Patients with obesity and HFpEF without epicardial coronary artery disease (CAD) underwent Doppler echocardiography to measure diastolic function, followed by vasodilator stress CMR, using a single bolus, dual sequence, quantitative myocardial perfusion mapping to measure myocardial blood flow (MBF) at rest and at peak hyperemia. With this, myocardial perfusion reserve (MPR), global stress endocardial-to-epicardial (endo:epi) perfusion ratio, and total ischemic burden (IB, defined as myocardial segments with MBF < 1.94 mL/min/g) were calculated. Results are reported as median and interquartile range. Results – Nineteen subjects were enrolled (100% female, 42% Black). Median age was 64 [56–72] years. Global stress MBF was 2.43 ml/min/g [2.16–2.78] and global myocardial perfusion reserve (MPR) was 2.34 [2.07–2.88]. All had an abnormal subendocardial perfusion with an endo:epi of less than 1 (0.87 [0.81–0.90]). Regional myocardial hypoperfusion was detected in 14 (74%) patients with an IB of 6% [0-34.4]. Endo:epi ratio significantly correlated with IB (R=-0.510, p = 0.026) and measures of diastolic function (R = 0.531, p = 0.019 and R=-0.544, p = 0.014 for e’ and E/e’ respectively). Conclusion – Using a novel quantitative stress CMR myocardial perfusion mapping technique, women with obesity and HFpEF were found to have patterns of abnormal subendocardial perfusion which significantly correlated with measures of diastolic dysfunction.

Cardiac remodeling in moderate aortic stenosis

“…The perfusion dynamics of the epicardial and endocardial layers differ in severe AS, with preferential flow shifting from the endocardium to epicardium 13 . Automated in-line myocardial perfusion quantification using CMR also provides a comprehensive assessment of the endocardium and epicardium perfusion 14 . Moreover, 31 phosphorus magnetic resonance spectroscopy ( 31 P-MRS) allows non-invasive assessment of the myocardial energetic state 15 .…”

Obesity, Preserved Ejection Fraction Heart Failure, and Left Ventricular Remodeling

“…Further, in addition to functional microvascular derangements, coronary microvascular rarefaction reduces myocardial O 2 delivery in HFpEF [131]. Stress CMR shows that abnormal subendocardial perfusion correlates with LVDD in women with obesity and HFpEF [132]. Myocardial ischemia due to CMD may increase cardiac afterload and thereby contribute to the pathogenesis of HFpEF [132,133].…”

“…Stress CMR shows that abnormal subendocardial perfusion correlates with LVDD in women with obesity and HFpEF [132]. Myocardial ischemia due to CMD may increase cardiac afterload and thereby contribute to the pathogenesis of HFpEF [132,133]. Although HFpEF and microvascular/endothelial dysfunction are unequivocally associated, a causal relationship has not been established [134].…”

Assessment of Microvascular Disease in Heart and Brain by MRI: Application in Heart Failure with Preserved Ejection Fraction and Cerebral Small Vessel Disease

“…Accurate assessment of diastolic function is crucial for the diagnosis of HFpEF, with increasing evidence that it is associated with microvascular disease [ 69 , 70 , 71 ]. Transmitral flow velocities generating E (passive diastolic flow) and A waves (active diastolic flow) can be determined using phase-contrast CMR and correlate fairly with reference standard echocardiography [ 72 ].…”

“…The above studies have examined global values for MBF and MPR; however, the latest iteration of quantitative perfusion sequences [ 78 , 79 ] utilises CMRs superior spatial resolution to automatically segment the heart into not just the regional 16-segment model but further subdivide each segment into an endocardial and epicardial component. This allows the quantification of an endocardial/epicardial ratio that can quantify the degree of inducible subendocardial ischaemia, which has long been suggested as a risk factor for HF and MACE, not just in HFpEF but across cardiovascular diseases [ 71 ].…”