Evaluation of cardiomyopathy diagnosis in heart transplant recipients: comparison of echocardiographic and pathologic classification

The discrepancies between clinical and histopathological diagnoses of cardiomyopathies in patients with stage D heart failure undergoing heart transplantation

Background

This study aimed to determine the etiology of stage-D heart failure (HF) and the prevalence and prognosis of misdiagnosed cardiomyopathy in patients undergoing heart transplantation.

Methods and results

We retrospectively reviewed 127 consecutive patients (mean age, 42 years; 90 [71%], male) from February 1994 to September 2021 admitted for heart transplant in our tertiary center. Pre-transplant clinical diagnosis was compared with post-transplant pathological diagnosis. The most common misdiagnosed cardiomyopathy was nonischemic cardiomyopathy accounting for 6% (n = 8) of all patients. Histopathological examination of explanted hearts in misdiagnosed patients revealed 2 arrhythmogenic cardiomyopathy, 2 sarcoidosis, 1 hypertrophic cardiomyopathy, 1 hypersensitivity myocarditis, 1 noncompacted cardiomyopathy, and 1 ischemic cardiomyopathy. Pre-transplant cardiac MRI and endomyocardial biopsy (EMB) were performed in 33 (26%) and 6 (5%) patients, respectively, with both performed in 3 (3% of patients). None of the patients undergoing both cardiac tests were misdiagnosed. During the 5-years follow-up period, 2 (25%) and 44 (37%) patients with and without pretransplant misdiagnosed cardiomyopathy died. There was no difference in survival rate between the groups (hazard ratio: 0.52; 95% CI:0.11–2.93; P = 0.314).

Conclusions

The prevalence of misdiagnosed cardiomyopathy was 6% of patients with stage-D HF undergoing heart transplantation, the misdiagnosis mostly occurred in nonischemic/dilated cardiomyopathy. An accurate diagnosis of newly detected cardiomyopathy gives an opportunity for potentially reversing cardiomyopathy, including sarcoidosis or myocarditis. This strategy may minimize the need for advanced HF therapy or heart transplantation. With advances in cardiac imaging, improvements in diagnostic accuracy of the etiology of HF can improve targeting of treatment.