Prognostic relevance of electrocardiographic abnormalities according to EGFR categories

Electrocardiogram (ECG) abnormalities are associated with adverse cardiovascular outcomes in patients with chronic kidney disease (CKD), but their prognostic relevance according to estimated glomerular filtration rate (eGFR) categories remains unexplored. This study investigated the associations between no, minor, and major ECG abnormalities and fatal cardiovascular disease (CVD) according to different strata of renal function.This was a retrospective cohort study including 310.060 individuals aged ≥16 years from the Copenhagen General Practitioners' Laboratory that had an available digital ECG and creatinine measurement within 7 days from 2001–2015. eGFR was calculated using The Chronic Kidney Disease Epidemiology Collaboration equation, and data were cross-linked with Danish nation-wide healthcare registries to gain information on medication, comorbidity, and fatal CVD. ECG abnormalities were categorized as either no abnormalities, minor (first‐degree atrioventricular block, incomplete bundle branch block or corrected QT prolongation) or major (left ventricular hypertrophy, atrial fibrillation/flutter, bundle branch block, Q waves, or ST‐T deviations), as done previously [1]. Patients with both minor and major ECG abnormalities were assigned as major ECG abnormalities. ECG abnormalities and their association with fatal CVD were compared across strata of renal function [eGFR (ml/min/1.73m2) \gt;90, 61–90, 46–60, 31–45, 16–30 and ≤15] based on multivariable Cox-regression analysis adjusted for age, sex, and comorbidities. Counterfactual G-estimation of Hazard Ratios (HRs) standardized to age and sex was performed to estimate 5-year absolute risk of fatal CVD.The median age was 55 [IQR, 41-69] years and 46\up time was 10.3 [IQR, 6.7-14.4] years. A total of 47,249 (17.9\ of the included patients had an eGFR \lt;60. The rate of fatal CVD according to ECG abnormalities and their adjusted HRs is shown in Fig. 1, while 5-year standardized risk of fatal CVD is depicted in Fig. 2. Generally, having minor or major ECG abnormalities, conferred a worse prognosis across all eGFR strata, with the highest 5-year absolute risk of fatal CVD being observed among patients with major ECG abnormalities and an eGFR between 31–45 [19\95\ 18–20\], eGFR 16–30 [25\95\ 24–26\] or an eGFR ≤15 [27.5\95\ 24–31\], Fig. 1–2.Figure 1:Multivariable Cox-regression of the association between fatal cardiovascular disease and eGFR categories across no, minor and major ECG abnormalities. Adjusted for age, sex, heart failure, coronary artery disease, atrial fibrillation/flutter, hypertension, hyperlipidemia, diabetes, chronic obstructive pulmonary disease and QT-prolonging medications.Figure 2:Standardized 5-year absolute risk of fatal cardiovascular disease across no, minor and major ECG abnormalities. Absolute risks are depicted with error bars representing ± standard error.In a population-based setting, having minor or major ECG abnormalities were associated with an increased risk of fatal CVD across all strata of renal function. Patients with an eGFR ≤45 and major ECG abnormalities represent a high-risk population, that might benefit from careful monitoring and cardiovascular risk management.