ramipril and Hypokalemia

In the Ongoing Telmisartan Alone and in Combination with Ramipril Trial (ONTARGET), dual agent renin-angiotensin-aldosterone system (RAAS) blockade with angiotensin-converting-enzyme inhibitors (ACEIs) and angiotensin receptor blockers (ARBs) did not reduce the risk of renal and cardiovascular outcomes compared with the single use of either agent. Dual therapy however increased the incidence of hyperkalemia. We examined risk factors for hyper- and hyokalemia and hypothesized that both would be associated with worse cardiovascular and renal outcomes.. A post-hoc analysis of the ONTARGET trial comparing dual therapy (ramipril and telmisartan) vs monotherapy (ramipril or telmisartan) was performed. The association between serum potassium at week 6 on cardiovascular and renal outcomes during the 56 months follow-up was assessed by multivariate Cox analysis. The main cardiovascular outcome was the composite of cardiovascular death, myocardial infarction, stroke, or hospitalization for heart failure. The renal outcome was defined as the composite of a doubling of serum creatinine or chronic dialysis.. Six weeks after randomization, hyperkalemia developed in 210 (2.7%) patients on dual therapy vs. 264 (1.6%) patients on monotherapy (p < 0.001 vs. dual therapy). Hypokalemia developed in 87 (1.1%) patients on dual therapy vs. 200 (1.2%)patients on monotherapy. Serum potassium was nonlinearly associated with cardiovascular and renal events with a nadir between 4.0-5.0 mmol/l for cardiovascular and 4.0-4.5 mmol/l for renal events such that subjects above or below these values exhibited higher risks. This association was independent of age, gender, diabetes, estimated glomerular filtration rate, systolic blood pressure and diuretic use.. With the precautions stipulated by the protocol of the ONTARGET trial, hypokalemia and hyperkalemia were infrequent events. Nevertheless, both high and low serum potassium were associated with an increased risk of cardiovascular and renal disease.

Topics: Aged; Angiotensin II Type 1 Receptor Blockers; Angiotensin-Converting Enzyme Inhibitors; Antihypertensive Agents; Benzimidazoles; Benzoates; Blood Pressure; Creatinine; Drug Therapy, Combination; Female; Heart Failure; Hospitalization; Humans; Hyperkalemia; Hypertension; Hypokalemia; Kidney; Kidney Diseases; Logistic Models; Male; Middle Aged; Multivariate Analysis; Myocardial Infarction; Nonlinear Dynamics; Odds Ratio; Potassium; Proportional Hazards Models; Ramipril; Renal Dialysis; Renin-Angiotensin System; Risk Assessment; Risk Factors; Stroke; Telmisartan; Time Factors; Treatment Outcome

Both hyper- and hypokalemia increase cardiovascular risk. Modest hyperkalemia is common with angiotensin-converting enzyme inhibition. We studied post-hoc the association of an initial, on-treatment serum potassium measurement with subsequent cardiovascular outcomes over 4.5 years in 9297 individuals at high cardiovascular risk, randomized to an ACE inhibitor or to placebo.. Post-hoc analysis of cardiovascular outcomes, as related to serum potassium levels, in the HOPE (Heart Outcomes and Prevention Evaluation) study which compared ramipril to placebo, and included 692 patients with a serum potassium level >5.0 mM and 137 with a serum potassium level <3.5 mM, defined as hyper- and hypokalemia, respectively. Serum potassium was measured 1 month after start of randomized treatment.. With hyperkalemia, the primary event rate was unchanged compared to normokalemia (15.5 vs 15.7%, p > 0.4, respectively), with hypokalemia, the primary event rate was higher (22.6% vs 15.5%, respectively, p = 0.023). The hazard ratio for the primary outcome associated with this initial hypokalemia was 1.44 (1.00-2.06) on multivariate analysis. The combined primary outcome (myocardial infarction, cardiovascular death, stroke) was not different throughout deciles of serum potassium but the lowest and highest deciles included many with normokalemia. Randomized treatment was withheld because of hyperkalemia in 8 and 6 people allocated to ramipril and placebo, respectively. The benefit of ramipril on cardiovascular outcomes was independent of serum potassium, but ramipril reduced hypokalemia in the entire cohort (1.15 vs 1.86% with placebo, p = 0.005), particularly in those participants on diuretics (3.8% vs 6.5%, p = 0.07).. In patients at high cardiovascular risk, modest hypokalemia predicts a less favorable outcome while modest hyperkalemia does not. Ramipril reduces hypokalemia and decreases risk.

Topics: Aged; Angiotensin-Converting Enzyme Inhibitors; Cardiovascular Diseases; Female; Humans; Hyperkalemia; Hypokalemia; Male; Middle Aged; Potassium; Ramipril; Risk Factors; Treatment Outcome