Magnetic resonance assessment of left ventricular diastolic dysfunction for detecting cardiac allograft vasculopathy in recipients of heart transplants

Abstract

Cardiac allograft vasculopathy (CAV) is a major late complication in heart transplant recipients, graded based on intravascular ultrasound (IVUS), and accelerates left ventricular (LV) diastolic dysfunction. We investigated the clinical feasibility of using magnetic resonance (MR) to assess LV diastolic dysfunction noninvasively in transplant recipients. Thirty-eight asymptomatic recipients (25 men, 37.2 ± 14.9 years) underwent both IVUS and cardiac MR. Based on IVUS, we divided the individuals into 2 groups using Stanford classification to categorize CAV development as either nonsignificant or advanced. We measured LV peak filling rate (PFR) and systolic function parameters, including LV ejection fraction (EF), stroke volume (SV), and cardiac output (CO) using cine MR; compared those values between groups; calculated receiver operating characteristic curve in the relationship between PFR value and CAV; and assessed myocardial late gadolinium enhancement (LGE) on contrast-enhanced MR. We classified CAV as advanced in 20 patients (53%) and nonsignificant in 18 (47%). LV EF, SV, and CO values were not significantly different. PFR was significantly lower in the advanced (3.63 ± 0.90 EDV/s) than nonsignificant group (4.43 ± 0.84 EDV/s, P = 0.01). The area under the curve was 0.76. We observed no myocardial LGE. MR measurement of PFR may permit noninvasive assessment of diastolic dysfunction associated with CAV before LV systolic dysfunction and myocardial infarction or scar formation develop.

The role of non-invasive imaging modalities in cardiac allograft vasculopathy: an updated focus on current evidences

“…ICA, invasive coronary angiography; LAD, left anterior descending artery; LCx, left circumflex artery; LM, left main artery; LV, left ventricle; LVEF, left ventricular ejection fraction; MBF, myocardial blood flow; OM, obtuse marginal; RV, right ventricle. Adapted from Bravo PE et al, 2018 (10.1093/eurheartj/ehx683) [ 87 76 ] …”

“…First encouraging data derive from the analysis of the peak filling rate, which is an estimate of diastolic function, whose values were lower in advanced CAV rather than in earlier stages. Indeed, early diastolic strain rate impairment was successively associated to microvascular dysfunction [ 86 ], while LVEF, stroke volume and cardiac output may be found normal either in early and late stages [ 87 ]. These results might hint that diastolic dysfunction in this population might be more sensitive than indexes of systolic function for the precocious detection of CAV.…”

Factors associated with cardiac allograft vasculopathy after heart transplantation

“…Furthermore, the CAV2/3 group had a significantly larger LV dimension than the CAV1 group. Previous studies have shown that LV function is an important prognostic factor in patients after HT, and the presence of CAV is associated with diastolic and systolic dysfunction of the LV [ 32 – 36 ]. Another study also showed a significant increase in LV end systolic volume and end diastolic volume in patients with moderate and severe CAV [ 36 ].…”

Cardiac allograft vasculopathy: A review

“…Other than measuring myocardial perfusion, diastolic strain evaluation has also been shown to be a valuable parameter in the determination of CAV . Assessing other parameters, such as peak filling rate may allow for the evaluation of diastolic dysfunction that is associated with CAV before left ventricular systolic dysfunction and myocardial infarction or scar come to fruition . Diastolic dysfunction as assessed by MR has additionally been found to precede impairment in CFR, which is associated with CAV in asymptomatic OHT recipients .…”