Coronary microvascular dysfunction was present in 57% of ATTRwt-CM patients, with IMR correlating significantly with BNP and troponin T only in ATTRwt-CM cases.
What is the prevalence and pathophysiological pattern of coronary microvascular dysfunction in patients with ATTRwt-CM compared to non-ATTR-CM?
Coronary microvascular dysfunction is highly prevalent in ATTRwt-CM and is characterized predominantly by elevated microvascular resistance, which correlates with biomarkers of myocardial injury.
Absolute Event Rate: 0% vs 0%
Abstract Background Wild-type amyloid transthyretin cardiomyopathy (ATTRwt-CM) is an infiltrative disease caused by the progressive deposits of transthyretin amyloid in the myocardium by aging and thus currently considered a more common cause of heart failure in the elderly. Amyloid fibril accumulation increases resistance in coronary microcirculation and results in the high prevalence of coronary microvascular dysfunction (CMD) in cardiac amyloidosis. However, the prevalence and determinants of CMD among patients with ATTRwt-CM using invasive modality remains unknown. Purpose We aimed to investigate the prevalence and determinants of CMD in patients with ATTRwt-CM using intracoronary temperature-pressure wire. Methods Patients with cardiac hypertrophy, defined as interventricular septum thickness ≥12 mm, undergoing invasive CMD assessment were prospectively enrolled. Patients with renal failure (eGFR30), decompensated heart failure, or significant coronary artery disease (visual stenosis 90%) were excluded. ATTRwt-CM was diagnosed by endomyocardial biopsy and genetic testing. CMD was invasively assessed by bolus intracoronary thermodilution using PressureWire X and Coroventis CoroFlow Cardiovascular System and was defined as coronary flow reserve (CFR) 2.0 or index of microvascular resistance (IMR) ≥25. Results A total of 50 patients (ATTRwt-CM: n=21, non-ATTR-CM: n=29 hypertrophic cardiomyopathy: n=16, hypertensive heart disease: n=13) were analyzed. Among patients with ATTRwt-CM, the mean age was 79 years and 86% were male. Overall, 62% of the study population had CMD, with a similar prevalence between the 2 groups (57% in ATTRwt-CM and 66% in non-ATTR-CM, P=0.547) (Abstract Picture 1). Among 31 patients with CMD, IMR ≥25 was more dominant in the ATTRwt-CM group (91.7%, n=11/12), whereas CFR 2.0 was more common in the non-ATTR-CM group (78.9%, n=15/19). In patients with ATTRwt-CM, IMR was significantly correlated with BNP (r=0.479, p=0.028) and troponin T (r=0.460, p=0.041), while there were no significant correlations between IMR and brain natriuretic peptide (BNP) (r=0.095, p=0.630), and IMR and troponin T (r=-0.180, p=0.390) in patients with non-ATTR-CM (Abstract Picture 2). Conclusions CMD was highly prevalent in patients with ATTRwt-CM. Significant association between IMR and cardiac biomarkers such as troponin T and BNP observed only in patients with ATTRwt-CM may suggest the pathophysiological role of CMD in myocardial injury among patients with ATTRwt-CM.
Sunohara et al. (Sat,) reported a other. Coronary microvascular dysfunction was present in 57% of ATTRwt-CM patients, with IMR correlating significantly with BNP and troponin T only in ATTRwt-CM cases.