Markedly prolonged QTc interval in end-stage liver disease and risk of 30-day cardiovascular event after liver transplant

Abstract

Background and Aim: The proportional increase of corrected QT interval (QTc) along end-stage liver disease (ESLD) severity may lead to inconsistent outcome reporting if based on conventional threshold of prolonged QTc. We investigated the comprehensive QTc distribution among ESLD patients and assessed the association between QTc?>?500?ms, a criterion for diagnosing severe long-QT syndrome, and the 30-day major adverse cardiovascular event (MACE) after liver transplantation (LT) and identified the risk factors for developing QTc?>?500?ms. Methods: Data were collected prospectively from the Asan LT Registry between 2011 and 2018, and outcomes were retrospectively reviewed. Multivariable analysis and propensity score-weighted adjusted odds ratios (ORs) were calculated. Thirty-day MACEs were defined as the composite of cardiovascular mortality, arrhythmias, myocardial infarction, pulmonary thromboembolism, and/or stroke. Results: Of 2579 patients, 194 (7.5%) had QTc?>?500?ms (QTc500_Group), and 1105 (42.8%) had prolonged QTc (QTcP_Group), defined as QTc?>?470?ms for women and >450?ms for men. The 30-day MACE occurred in 336 (13%) patients. QTc500_Group showed higher 30-day MACE than did those without (20.1% vs 12.5%, P?=?0.003), with corresponding adjusted OR of 1.24 (95% CI: 1.06?1.46, P?=?0.007). However, QTcP_Group showed comparable 30-day MACE (13.3% vs 12.8% without prolonged QTc, P?=?0.764). Significant risk factors for QTc?>?500?ms development were advanced liver disease, female sex, hypokalemia, hypocalcemia, high left ventricular end-diastolic volume, and tachycardia. Conclusion: Our results revealed that, among ESLD patients, a novel threshold of QTc?>?500?ms was associated with post-LT 30-day MACE but not with conventional threshold, indicating that a longer QTc threshold should be considered for this unique patient population.