Heart-rate Corrected QT Interval and Statin use in the general population. The Polish Norwegian Study (PONS)

Abstract

<b>Abstract ID 55464</b> <b>Poster Board 309</b> <b>Introduction:</b> Prolonged QT interval is associated with cardiac arrhythmias and sudden death. The hERG potassium channel (IKr) plays a role in cardiac repolarization. Decreased IKr may lead to QT prolongation. Due to their structural similarity to Ikr blockers, statins have been suggested to prolong the QT interval in non-human models. <b>Purpose:</b> To compare the QT interval between statin users and non-users in a large community-based population. <b>Methods:</b> Cross-sectional data from an ongoing cohort study, following a standardized protocol. The QT intervals were obtained from digital standard 12-lead resting ECG. Heart rate correction (QTc) was performed with Bazett’s formula. We excluded individuals taking medication known to influence the QT interval (anti-arrhythmics, beta blockers, digoxin, anti-psychotics), as well as other conditions (coronary heart disease, atrial fibrillation, WPW syndrome, pacemakers). Generalized linear models were used for confounding control. <b>Results:</b> The analytic sample was 7439 participants, average age 54. 92 (SD 5.4) , 65.01 % women, 27.11% with hypertension, 4.27% with diabetes type 2. Mean (SD) QTc were 418.18 ms (45.58) for men and 426.41 ms ( 44.79) for women. Mean QTc was 399.5 ms (28.32) in statin users and 393.6 ms (28.88) in non-users. Compared to those not using statins, statin users had a longer mean QT interval by 3.20 ms (95%CI 0.79 - 5.62) after adjusting for age, sex, smoking, physical activity, hypertension, diabetes, and by 3.46 ms (95% CI 1.07 -5.84) after additional adjustment for left ventricular hypertrophy, T-wave inversion, presence of Q wave, ST segment elevation or depression and cardiac blocks. Pathologically abnormal QT prolongation (QTc &gt; 430 ms for men, &gt; 450 ms for women) was present in 9.61% of statin users and 9.10% of non-statin users (not statistically significant). Lipid lowering drugs other than statins were not associated with the QT interval duration. <b>Conclusion:</b> In a population free of diagnosed heart disease, we found a modest increase in the QTc interval among statin users compared to non-users, even after ample adjustment for additional clinical and electrocardiographic characteristics. <b>Implications:</b> While the overall cardioprotective effect of statins on cardiovascular risk is well-established, awareness of potential modest QT interval prolongation may be warranted, especially in a more complex clinical context of concomitant QT-prolonging medication. <b>FINANCIAL DISCLOSURE:</b> The data collection was supported by a grant from the Polish-Norwegian Research Fund (PNRF-228-AI-1/07)