Independent association of ECG abnormalities with microalbuminuria and renal damage in hypertensive patients without overt cardiovascular disease: data from Italy-Developing Education and awareness on MicroAlbuminuria in patients with hypertensive Disease study.

Objectives: Renal abnormalities are strongly associated with cardiac damage in essential hypertension. Detection of preclinical cardiac and renal abnormalities is a key clinical step in hypertension management. This study investigated the relationship between ECG abnormalities and microalbuminuria (MAU) in hypertensive patients without overt cardiovascular disease. This relationship, in fact, has never been extensively studied.

Methods: The study population was that of Italy-Developing Education and awareness on MicroAlbuminuria in patients with hypertensive Disease, a large observational study including 4121 hypertensive patients in Italy. Patients with overt cardiovascular diseases were excluded from the present analysis. ECGs were centrally read and urinary albumin/creatinine ratio was carefully assessed. Chronic kidney disease was defined by the presence of albuminuria or by a reduction of glomerular filtration rate.

Results: The presence of ECG abnormalities was significantly and directly associated with chronic kidney disease [odds ratio (OR) 1.66, 95% confidence interval (CI) 1.32-2.07, P<0.001], particularly with MAU (OR 1.81, 95% CI 1.39-2.36, P<0.001). Main selected ECG abnormalities were also significantly associated with MAU [rhythm abnormalities (OR 2.94, 95% CI 1.77-4.88, P<0.001), intraventricular conduction defects (OR 1.95, 95% CI 1.32- 2.87, P<0.01), ventricular repolarization alterations (OR 1.84, 95% CI 1.26-2.70, P<0.01) and left-axis deviation (OR 1.87, 95% CI 1.26-2.79, P<0.01)]. After adjustment for confounders, an abnormal ECG and all the main ECG abnormalities remained significantly associated with MAU.

Conclusion: This is the first large and systematic analysis of the relationship between detailed ECG abnormalities and MAU/chronic kidney disease in hypertensive patients without overt cardiovascular diseases. We report a significant and independent relationship between the presence of ECG abnormalities and renal damage in a preclinical stage of hypertension. Identification of ECG abnormalities in hypertension should prompt physicians to careful detection for renal damage, also in order to achieve an accurate risk stratification.