The Significance of Angiotensin Converting Enzyme Inhibitor or Angiotensin II Receptor Blocker Use in Sudden Cardiac Death

Objectives: To investigate the relationship between the use of angiotensin converting enzyme (ACE) inhibitor or angiotensin II receptor blocker (ARB) and hyperkalemia in patients diagnosed with sudden cardiac death. Methods: We examined oral ACE inhibitor or ARB use among cardiopulmonary arrest patients brought by ambulance to our emergency room during a 5-year period from January 2012 to December 2016. The cause of death was determined to be sudden cardiac death, despite temporary return of spontaneous circulation after starting cardiopulmonary resuscitation. Subjects were dichotomized into 2 groups, those taking and those not taking an ACE inhibitor or ARB. Variables determined retrospectively included serum potassium, estimated glomerular filtration rate as an index of kidney function and time from cardiopulmonary arrest to return of spontaneous circulation. The Mann-Whitney U-test was used to compare continuous data, and the chi-square test to compare categorical data between groups. The results are expressed as the median plus range. Statistical significance was assumed at p < 0.05. Results: Thirty-five patients met the inclusion criteria. The mean age was 77.1 years (range, 35 - 93 years), and there were 26 males and 9 females. Eleven subjects were ACE inhibitor or ARB users, and 24 were non-users. The serum potassium level was significantly higher in users than non-users (median, 6.2 mEq/L (range, 4.5 - 10.0) vs. 5.2 mEq/L (range, 3.6 - 8.3); p = 0.001). The estimated glomerular filtration rate was significantly lower in users than non-users (median, 25.1 mL/min/1.73 m2 (range, 4.6 - 60.3) vs. 46.9 mL/min/1.73 m2 (range, 19.8 - 97.1); p = 0.009). There was no significant difference in time from cardiopulmonary arrest to return of spontaneous circulation between the 2 groups (median, 24 minutes (range, 3 - 111) vs. 29 minutes (range, 10 - 54); p = 0.355). Conclusion: It is possible that hyperkalemia induced by ACE inhibitor or ARB use is a cause of sudden cardiac death, especially in patients with chronic kidney disease.