Prevalence and Prognosis of Hyperkalemia in Patients with Acute Myocardial Infarction

Abstract

Background Hyperkalemia is common and potentially dangerous in hospitalized patients; its contemporary prevalence and prognostic importance following acute myocardial infarction are not well described. Methods In 38,689 consecutive acute myocardial infarction patients from the Cerner Health Facts database, we evaluated the association between maximum in-hospital potassium levels (max K) and in-hospital mortality. Patients were stratified by dialysis status, and grouped by max K as follows: <5 mEq/L, 5–<5.5 mEq/L, 5.5–<6.0 mEq/L, 6.0–<6.5 mEq/L, and ≥ 6.5 mEq/L. Multivariable logistic regression was used to adjust for multiple patient and site characteristics. The relationship between number of hyperkalemic values and in-hospital mortality was also evaluated. Results Of 38,689 acute myocardial infarction patients, 886 were on dialysis. The rate of hyperkalemia (max K ≥ 5.0 mEq/L) was 22.6% in non-dialysis and 66.8% in dialysis patients. Moderate-severe hyperkalemia (max K ≥ 5.5 mEq/L) occurred in 9.8% of patients. There was a steep increase in mortality with higher max K levels. In-hospital mortality exceeded 15% once max K ≥5.5 mEq/L regardless of dialysis status. The relationship between higher max K and increased mortality risk persisted after multivariable adjustment. In addition, patients with greater number of hyperkalemic values (vs. a single value) experienced higher in-hospital mortality. Conclusions Hyperkalemia is common in patients hospitalized with acute myocardial infarction. Higher max K levels and number of hyperkalemic events are associated with a steep mortality increase; with higher risks for adverse outcomes observed even at mild levels of hyperkalemia. Whether more intensive management of hyperkalemia may improve outcomes in acute myocardial infarction patients merits further study.

How Dangerous Is Hyperkalemia?

“…Furthermore, An et al 31 showed a graded decrease in risk of death among patients with extreme levels of hyperkalemia (.6.5 meq/L) as CKD stage increased (OR for death with stage 2, 3, 4, and 5 CKD, 0.52; 95% CI, 0.35 to 0.78, 0.31; 95% CI, 0.21 to 0.46, 0.13; 95% CI, 0.06 to 0.26, and 0.17; 95% CI, 0.11 to 0.27). Similar results were observed among dialysis versus non-CKD patients with hyperkalemia and AMI in the studies performed by Goyal et al 37 and Grodzinsky et al 38 One prospective observational analysis of sustained hyperkalemia and outcomes in patients with creatinine clearance ,50 ml/min demonstrated that hyperkalemia in the ranges of 5.0-6.0 meq/L (using an average of six measurements per patient) appeared to be well tolerated. 47 Adaptive increases in circulating catecholamines, aldosterone, and augmentation of renal and gastrointestinal (GI) potassium elimination are thought to blunt hyperkalemia development in CKD and could partially explain this apparent disconnect in mortality relative to non-CKD patients.…”

“….0, 5.0-5.5, 5.5-6.0, 6.0-6.5, and .6.5 meq/L, respectively). 38 Another retrospective trial analyzing 90-day mortality in 2596 Danish patients with heart failure post-AMI also supports that a serum potassium .5.1 meq/L is associated with higher risk of death (HR, 2.3; 95% CI, 1.4 to 3.6). 39 The studies by Goyal et al 37 and Grodzinsky et al 38 are strengthened by use of robust adjustment models that control for baseline risk, medications, PCI use, and other pertinent factors.…”

“…38 Another retrospective trial analyzing 90-day mortality in 2596 Danish patients with heart failure post-AMI also supports that a serum potassium .5.1 meq/L is associated with higher risk of death (HR, 2.3; 95% CI, 1.4 to 3.6). 39 The studies by Goyal et al 37 and Grodzinsky et al 38 are strengthened by use of robust adjustment models that control for baseline risk, medications, PCI use, and other pertinent factors. Nevertheless, residual confounding in very ill patients is common in retrospective analyses, and outcomes in patients with serum potassium .4.5 meq/L in the study by Goyal et al 37 were ultimately driven by a small number of individuals (11%, 2%, and 0.6% of the entire cohort had potassium levels 4.5-5.0, 5.1-5.5, and .5.5 meq/L, respectively).…”

Real World Evidence for Treatment of Hyperkalemia in the Emergency Department (REVEAL–ED): A Multicenter, Prospective, Observational Study

“…With the ethical conflict of not treating a potentially fatal pathology, no randomized interventional hyperkalemia treatment trials have been published. Observational data suggest that lowering potassium levels in patients with hyperkalemia is associated with lower mortality (10)(11)(12).…”

Evaluation of prognostic role of serum potassium in patients with Acute Myocardial Infarction: A cross-sectional study from a tertiary hospital in northern India

“…Our results were found to be in correlation with the results obtained by previous authors who have reported a male preponderance in AMI groups of their respective studies. 14,15 Hypokalemia was found in 24% cases, hyperkalemia in 6% and 70% were normokalemic. Our results were in correlation with the results obtained by studies of past literature, which have reported that prevalence of hypokalemia in AMI patients varies from 9 % to 25 %.…”