Prediabetes and incident heart failure in hypertensive patients: Results from the Swedish Primary Care Cardiovascular Database

Backgrounds and aimsThe cardiovascular risk conferred by concomitant prediabetes in hypertension is unclear. We aimed to examine the impact of prediabetes on incident heart failure (HF) and all-cause mortality, and to describe time in therapeutic blood pressure range (TTR) in a hypertensive real-world primary care population.Methods and resultsIn this retrospective cohort study, 9628 hypertensive individuals with a fasting plasma glucose (FPG) in 2006–2010 but no diabetes, cardiovascular or renal disease were followed to 2016; median follow-up was 9 years. Prediabetes was defined as FPG 5.6–6.9 mmol/L, and in a secondary analysis as 6.1–6.9 mmol/L. Study outcomes were HF and all-cause mortality. Hazard ratios (HR) were compared for prediabetes with normoglycemia using Cox regression. All blood pressure values from 2001 to the index date (first FPG in 2006–2010) were used to calculate TTR. At baseline, 51.4% had prediabetes. The multivariable-adjusted HR (95% confidence intervals) was 0.86 (0.67–1.09) for HF and 1.06 (0.90–1.26) for all-cause mortality. For FPG defined as 6.1–6.9 mmol/L, the multivariable-adjusted HR were 1.05 (0.80–1.39) and 1.42 (1.19–1.70), respectively. The prediabetic group had a lower TTR (p < 0.05).ConclusionsPrediabetes was not independently associated with incident HF in hypertensive patients without diabetes, cardiovascular or renal disease. However, prediabetes was associated with all-cause mortality when defined as FPG 6.1–6.9 mmol/L (but not as 5.6–6.9 mmol/L). TTR was lower in the prediabetic group, suggesting room for improved blood pressure to reduce incident heart failure in prediabetes.