Objective: The aim of this study was to compare the predictive value of ECG abnormalities for atrial fibrillation in nonhypertensive versus hypertensive individuals.
Methods: We recorded ECG and measured conventional cardiovascular risk factors in a nationwide population-based sample of 5813 Finns. We divided the participants into nonhypertensive (n = 3148) and hypertensive (n = 2665) individuals and followed the participants for incident atrial fibrillation events. We evaluated the predictive ability of 12 ECG abnormalities for atrial fibrillation using multivariable-adjusted Fine-Gray models.
Results: During a follow-up of 11.9 ± 2.9 years, 111 nonhypertensive and 301 hypertensive participants developed atrial fibrillation. Negative T wave in lateral leads predicted atrial fibrillation in both nonhypertensive [hazard ratio (HR), 4.59; 95% confidence interval (95% CI) 1.84-11.44] and hypertensive participants (HR, 1.81; 95% CI 1.16-2.84). In nonhypertensive participants, 1-SD increments in corrected QT interval (HR, 1.42; 95% CI, 1.18-1.71) and T-wave amplitude in lead augmented vector R (aVR) (HR, 1.40; 95% CI, 1.10-1.80) were related to atrial fibrillation. In hypertensive participants, prolonged PR interval (HR, 1.59; 95% CI 1.05-2.41), prolonged P-wave duration (HR, 1.43; 95% CI 1.07-1.91), left ventricular hypertrophy by Sokolow-Lyon criteria (HR, 1.55; 95% CI, 1.12-2.14) and poor R-wave progression (HR, 1.59; 95% CI, 1.02-2.48) predicted atrial fibrillation. Corrected QT interval and T-wave amplitude in lead aVR were stronger predictors of atrial fibrillation in nonhypertensive than in hypertensive participants. ECG abnormalities improved risk prediction only marginally (delta area under receiver-operating-characteristic curve = 0.000-0.005).
Conclusion: Several ECG abnormalities associate with incident atrial fibrillation in hypertensive and nonhypertensive individuals but provide only marginal incremental predictive value. Corrected QT interval and T-wave amplitude in lead aVR may relate stronger to incident atrial fibrillation in nonhypertensive than in hypertensive individuals.