The relationship between myocardial fibrosis detected by cardiac magnetic resonance and Tp-e interval, 5-year sudden cardiac death risk score in hypertrophic cardiomyopathy patients.

Background: The aim of this study was to investigate the relationship between QT (QTc) interval, Tp-e interval, Tp-e/QTc ratio, 5-year sudden cardiac death (SCD) risk score, and late gadolinium enhancement (LGE) detected by CMR in hypertrophic cardiomyopathy (HCM) patients.

Method: A total of 74 consecutive patients who underwent CMR with HCM diagnosis were included in the study. These patients were divided into two groups according to the presence of LGE on CMR. All patients underwent detailed echocardiography and QTc interval, Tp-e interval, and Tp-e/QTc ratios and 5-year SCD risk scores were calculated. These parameters were compared for two groups.

Results: CMR revealed LGE in 32 (43.2%) of 74 HCM patients. In the group with LGE, significantly higher QTc interval (p = 0.002), Tp-e interval (p < 0.001), Tp-e/QTc ratio (p = 0.004), and 5-year SCD risk score were detected. In addition, QTc interval, Tp-e interval, Tp-e/QTc ratio, maximum wall thickness, left ventricular mass index, 5-year SCD risk score, and cardiac fibrosis index were found to be correlated with various degrees in correlation analysis. Also, Tp-e interval is found to be an independent predictor of LGE detected by CMR in HCM patients (p = 0.017, OR [%95 CI] = 1.017 [1.001-1.034]). In addition, the Tp-e interval can detect the LGE with a sensitivity of 64.3% and a specificity of 84.2% at 99.4 ms. (p < 0.001, AUC [95% CI] = 0.790 [0.676-0.905]).

Conclusion: The Tp-e interval can be used to optimize SCD risk stratification in HCM patients and determine which patients will benefit from implantable cardioverter-defibrillator (ICD) treatment.