Incidence of and Risk Factors for Severe Adverse Events in Elderly Patients Taking Angiotensin-Converting Enzyme Inhibitors or Angiotensin II Receptor Blockers after an Acute Myocardial Infarction

Effects of angiotensin II receptor blockers on serum potassium level and hyperkalemia risk: retrospective single-centre analysis

OBJECTIVE

To examine the effect of angiotensin II receptor blocker (ARB) treatment on serum potassium level and hyperkalaemia risk in a clinical setting with inpatients and outpatients using calcium channel blockers (CCBs) as a reference standard.

METHODS

The increased risk of hyperkalaemia associated with ARB treatment is known, however only a few studies have used an active comparator to examine this risk. In this retrospective study at a 320-bed general hospital in Japan, the hospital information system was used to identify patients with at least one prescription for an ARB (819 patients) or a CCB (1015 patients) who were naive to these drugs before study initiation. Serum potassium levels before and after ARB treatment were compared. Additionally, the unadjusted and adjusted hazard ratios for the risk of hyperkalaemia in the ARB and CCB users were estimated.

RESULTS

The serum potassium level was higher in patients receiving ARB treatment (0.05 mEq/L, p=0.02) compared with those on CCB treatment. However, there was no significant association between ARB use and hyperkalaemia (adjusted HR 0.91, 95% CI 0.42 to 1.99, p=0.82).

CONCLUSION

The increase in serum potassium level after ARB initiation makes it necessary to monitor serum potassium levels continuously during ARB treatment; however, the risk of hyperkalaemia appeared to be similar for ARB and CCB treatments.

A comparative study assessing the incidence and degree of hyperkalemia in patients on angiotensin-converting enzyme inhibitors versus angiotensin-receptor blockers

OVERVIEW

Angiotensin-converting enzyme inhibitors (ACEI) and angiotensin-receptor blockers (ARB) are the most commonly prescribed anti-hypertensive medications in the United States, yet whether ACEI or ARB use is associated with a greater risk of hyperkalemia remains uncertain. Using real-world evidence from electronic health records, our study demonstrates that treatment with ACEI is associated with both a higher incidence and greater degree of hyperkalemia than treatment with ARB in adjusted models, especially in patients with chronic kidney disease. Providers should therefore consider this possible difference in hyperkalemia risk when choosing between ACEI and ARB therapy.

Disparities by sex in P2Y12 inhibitor therapy duration, or differences in the balance of ischaemic-benefit and bleeding-risk clinical outcomes in older women versus comparable men following acute myocardial infarction? A P2Y12 inhibitor new user retrospective cohort analysis of US Medicare claims data

OBJECTIVES

To determine if comparable older women and men received different durations of P2Y₁₂ inhibitor therapy following acute myocardial infarction (AMI) and if therapy duration differences were justified by differences in ischaemic benefits and/or bleeding risks.

DESIGN

Retrospective cohort.

SETTING

20% sample of 2007-2015 US Medicare fee-for-service administrative claims data.

PARTICIPANTS

≥66-year-old P2Y₁₂ inhibitor new users following 2008-2013 AMI hospitalisation (N=30 613). Older women compared to older men with similar predicted risks of study outcomes.

PRIMARY AND SECONDARY OUTCOME MEASURES

Primary outcome: P2Y₁₂ inhibitor duration (modelled as risk of therapy discontinuation).

SECONDARY OUTCOMES

clinical events while on P2Y₁₂ inhibitor therapy, including (1) death/hospice admission, (2) composite of ischaemic events (AMI/stroke/revascularisation) and (3) hospitalised bleeds. Cause-specific risks and relative risks (RRs) estimated using Aalen-Johansen cumulative incidence curves and bootstrapped 95% CIs.

RESULTS

10 486 women matched to 10 486 men with comparable predicted risks of all 4 study outcomes. No difference in treatment discontinuation was observed at 12 months (women 31.2% risk; men 30.9% risk; RR 1.01; 95% CI 0.97 to 1.05), but women were more likely than men to discontinue therapy at 24 months (54.4% and 52.9% risk, respectively; RR 1.03; 95% CI 1.00 to 1.05). Among patients who did not discontinue P2Y₁₂ inhibitor therapy, women had lower 24-month risks of ischaemic outcomes than men (13.1% and 14.7%, respectively; RR 0.90; 95% CI 0.84 to 0.96), potentially lower 24-month risks of death/hospice admission (5.0% and 5.5%, respectively; RR 0.91; 95% CI 0.82 to 1.02), but women and men both had 2.5% 24-month bleeding risks (RR 0.98; 95% CI 0.82 to 1.14).

CONCLUSIONS

Risks for death/hospice and ischaemic events were lower among women still taking a P2Y₁₂ inhibitor than comparable men, with no difference in bleeding risks. Shorter P2Y₁₂ inhibitor durations in older women than comparable men observed between 12 and 24 months post-AMI may reflect a disparity that is not justified by differences in clinical need.

Renin-angiotensin-aldosterone system inhibitors and major cardiovascular events and acute kidney injury in patients with coronary artery disease

BACKGROUND

Renin-angiotensin-aldosterone system inhibitors (RAASIs) are recommended for most patients with coronary artery disease (CAD). However, there is debate across guidelines as to which patients with CAD benefit the most from these agents. This study investigated the association between RAASIs and cardiovascular outcomes and acute kidney injury in a contemporary cohort of patients with CAD.

METHODS

Patients ≥65 years of age with CAD alive on April 1, 2012 in Ontario, Canada were included. Outcomes included major adverse cardiovascular events (MACE: cardiovascular death, myocardial infarction (MI), unstable angina, stroke, or coronary revascularization), and acute kidney injury (AKI) hospitalizations at 4 years. Inverse probability of treatment-weighted Cox proportional hazards regression models was used to compare the rates of each outcome in patients treated with and without RAASIs (angiotensin-converting enzyme inhibitors or angiotensin II receptor blockers).

RESULTS

There were 165,058 patients with CAD identified (mean age 75 years, 65.5% male, 64.7% prescribed RAASIs). After inverse-probability weighting, treatment with RAASIs was associated with a lower rate of MACE compared with treatment without RAASIs (17.6% vs 18.2%, hazard ratio [HR]: 0.96, 95% CI: 0.93-0.99, respectively). However, treatment with RAASIs was associated with a higher rate of AKI compared with treatment without RAASIs (1.7% vs 1.5%, HR: 1.14, 95% CI: 1.02-1.29, respectively). The reduction in MACE was greater in patients with prior MI (HR: 0.87, 95% CI: 0.82-0.92) compared with patients without prior MI (HR: 1.00, 95% CI: 0.97-1.04, interaction p < 0.01). The increase in AKI was lower in patients with prior MI (HR: 0.82, 95% CI: 0.66-1.00) compared with patients without prior MI (HR: 1.37, 95% CI: 1.19-1.57, interaction p < 0.01).

CONCLUSIONS

This study supports the continued use of RAASIs in patients with CAD, although the benefit appears smaller in magnitude than observed in prior trials. High-risk patients, particularly those with prior MI, appear to benefit the most from RAASIs.

Applying machine learning to predict real-world individual treatment effects: insights from a virtual patient cohort

OBJECTIVE

We aimed to investigate bias in applying machine learning to predict real-world individual treatment effects.

MATERIALS AND METHODS

Using a virtual patient cohort, we simulated real-world healthcare data and applied random forest and gradient boosting classifiers to develop prediction models. Treatment effect was estimated as the difference between the predicted outcomes of a treatment and a control. We evaluated the impact of predictors (ie, treatment predictors [X1], confounders [X2], treatment effects modifiers [X3], and other outcome risk factors [X4]) with known effects on treatment and outcome using real-world data, and outcome imbalance on predicting individual outcome. Using counterfactuals, we evaluated percentage of patients with biased predicted individual treatment effects.

RESULTS

The X4 had relatively more impact on model performance than X2 and X3 did. No effects were observed from X1. Moderate-to-severe outcome imbalance had a significantly negative impact on model performance, particularly among subgroups in which an outcome occurred. Bias in predicting individual treatment effects was significant and persisted even when the models had a 100% accuracy in predicting health outcome.

DISCUSSION

Inadequate inclusion of the X2, X3, and X4 and moderate-to-severe outcome imbalance may affect model performance in predicting individual outcome and subsequently bias in predicting individual treatment effects. Machine learning models with all features and high performance for predicting individual outcome still yielded biased individual treatment effects.

CONCLUSIONS

Direct application of machine learning might not adequately address bias in predicting individual treatment effects. Further method development is needed to advance machine learning to support individualized treatment selection.

Association between serum 25-hydroxyvitamin D and the effects of Angiotensin II receptor blocker on renal function among African Americans: A post hoc analysis of a randomized placebo-controlled trial

We tested the hypothesis that vitamin D status may modify the effect of Angiotensin II receptor blocker (ARB) on renal function among African Americans. Sixty-four participants were included in this ancillary study from a randomized, double-blind, placebo-controlled, crossover trial among normotensive African Americans to test the effect of ARB on stress response of blood pressure and renal sodium handling. The participants were randomly assigned to receive either ARB or placebo for one week, washed out for one week and then cross-overed to receive the other intervention for one week. On the final day of each intervention, the participant underwent a mental stress test. Baseline serum 25-hydroxyvitamin D [25(OH)D] level was measured in this ancillary study. Sixty-four participants were included, aged 26.5 ± 10.2 years and 47% were female. Among the participants with the serum 25(OH)D concentrations in the low tertile, ARB treatment was associated with 2.58 mg/dL higher blood urea nitrogen (BUN) (P < .001) and was not associated with serum creatinine (SCr) or estimated glomerular filtration rate (eGFR) (Ps > .05). Among the participants in the high 25(OH)D tertile, ARB was associated with 1.59 mg/dL lower BUN (P < .001), 0.08 mg/dL lower SCr (P = .001), and 8.59 mL/min/1.73 m² higher eGFR (P = .001). The interactions between vitamin D and ARB on renal function were more significant during stress and recovery than at rest. The effects of ARB treatment on renal function are modified by the vitamin D status among African Americans. ARB may improve renal function only among the ones with optimal vitamin D status.

Low body mass index is a risk factor for hyperkalaemia associated with angiotensin converting enzyme inhibitors and angiotensin II receptor blockers treatments

WHAT IS KNOWN AND OBJECTIVE

Angiotensin converting enzyme inhibitors (ACEI) and angiotensin II receptor blockers (ARB) represent the cornerstones of hypertension and congestive heart failure treatment. Risk factors for hyperkalaemia associated with ACEI and ARB are chronic kidney disease and concomitant medications which increase serum potassium level. Body mass index (BMI) also affects pharmacokinetics of ACEI and ARB and potassium disposition. We evaluated the relationship between BMI and hyperkalaemia associated with ACEI and ARB treatments.

METHODS

Study design is a retrospective case-control analysis. Patients who had been prescribed ACEI or ARB between June 2015 and June 2017 at Tokyo Women's Medical University, Medical Center East, were included. Patient clinical background was collected from medical records. Hyperkalaemia was defined as serum potassium above 5.5 meq/L. The concomitant use of ACEI and ARB, aldosterone antagonists, direct renin inhibitor, sulfamethoxazole-trimethoprim and non-steroidal anti-inflammatory drugs (NSAIDs) was regarded as hyperkalaemia-inducing medications. The relationship between BMI and hyperkalaemia associated with ACEI and ARB treatments was assessed using multivariable logistic regression analysis.

RESULTS AND DISCUSSION

The study included 2987 patients aged 70.1 ± 12.9 years, 61.0% were men, and BMI was 23.8 ± 4.4 kg/m² . The incidence of hyperkalaemia was 7.8%. Multivariable logistic regression analysis revealed that age >65 years, low BMI, diabetes, history of treatment for hyperkalaemia, serum sodium <135 meq/L, eGFR <30 mL/min/1.73m² and the concomitant use of hyperkalaemia-inducing medications were independent risk factors for hyperkalaemia associated with ACEI and ARB.

WHAT IS NEW AND CONCLUSION

This study demonstrated that BMI provides useful information for the identification of potential risk for hyperkalaemia associated with ACEI and ARB treatments.