Hyperkalaemia in congestive heart failure patients using ACE inhibitors and spironolactone.
BACKGROUND
Recent studies have shown a fall in global mortality with minimal side effects in severe congestive heart failure (CHF) patients receiving angiotensin-converting enzyme inhibitors (ACEI) plus spironolactone (SLN). However, the risk of hyperkalaemia due to ACEI may be increased by the concomitant use of SLN.


METHODS
We conducted a retrospective cohort study by examining consecutive cases of severe decompensated CHF admitted to a university hospital in Brazil from March 1999 to March 2000, which had used ACEI with or without SLN. We reviewed charts for the 30 days following admission and assessed various therapeutic regimens used for heart failure as well as serum potassium and creatinine, before and after drug exposure. The primary end-point was the development of hyperkalaemia (K > or = 5.5 mEq/l). For analysis, the subjects were split into patients treated with ACEI/SLN (n = 49) and patients treated with ACEI (n = 51) by itself.


RESULTS
Although demographical and clinical features were comparable between the two groups, ACEI/SLN patients had a higher proportion of class IV CHF. We found 16 cases of hyperkalaemia in ACE/SLN patients, but only one case in ACEI subjects. The odds ratio for developing hyperkalaemia in ACEI/SLN patients was 24. When class III CHF subjects were excluded, the odds ratio was 14.6 (95% confidence interval: 1.8-119.6). The best predictors of hyperkalaemia were class IV CHF, increases in creatinine following treatment and diabetes.


CONCLUSIONS
Patients with severe decompensated CHF using ACEI with SLN are at major risk for developing hyperkalaemia.
Cruz
Constança S
CS
Curso de Pós-graduação e Extensão em Medicina Interna da Fundação para Desenvolvimento das Ciências, Fundação Instituto Osvaldo Cruz, Salvador - Bahia, Brazil. conscruz@ig.com.br
Cruz
Alvaro A
AA
Marcílio de Souza
Carlos A
CA
D000328:Adult; D000368:Aged; D000806:Angiotensin-Converting Enzyme Inhibitors / Q000009:adverse effects* / Q000627:therapeutic use; D015331:Cohort Studies; D004232:Diuretics / Q000009:adverse effects* / Q000627:therapeutic use; D005260:Female; D006333:Heart Failure / Q000150:complications / Q000188:drug therapy*; D006801:Humans; D006947:Hyperkalemia / Q000139:chemically induced* / Q000150:complications; D008297:Male; D008875:Middle Aged; D012189:Retrospective Studies; D012720:Severity of Illness Index; D013148:Spironolactone / Q000009:adverse effects* / Q000627:therapeutic use
D000806:Angiotensin-Converting Enzyme Inhibitors; D004232:Diuretics; D013148:Spironolactone