Hemodialysis immediately after acute myocardial infarction

Abstract

Acute myocardial infarction (AMI) is common in patients who have end-stage renal disease. However, the prudent interval after AMI until resuming hemodialysis is unknown. Also incidence and severity of intradialytic morbid events during the initial dialysis treatment after AMI have not been determined. We conducted a retrospective analysis of the course of hemodialyses performed immediately after AMI in 13 maintenance hemodialysis patients (group 1) hospitalized with AMI over the 5-year period 1988-1992. For comparison, the incidence of intradialytic morbid events (hypotension--systolic blood pressure < 90 or diastolic blood pressure < 60 mm Hg or a fall in systolic or diastolic blood pressure of > 30 mm Hg--with and without symptoms, arrhythmias, and unplanned termination of hemodialysis was extracted from the charts of 9 maintenance hemodialysis patients (group 2) admitted during the same period with angina but no AMI, and in 13 stable ambulatory hemodialysis patients (group 3) dialyzed during the same period who had no evidence of heart disease. Patients in groups 1 and 2 were sorted by time interval from onset of chest pain to initiation of hemodialysis (< 12, 12-24, and > 24 h). In group 1, we examined the relationship of anatomic location of AMI, number of antihypertensive medications, predialysis left ventricular systolic ejection fraction, and various other clinical and laboratory parameters to the incidence intradialytic morbid events. The mean (+/- SD) age of the study subjects was 67 +/- 7.5 years in group 1, 57 +/- 3.7 in group 2, and 60 +/- 11 years in group 3 (p = 0.6). Arrhythmias and early termination of dialysis did not occur in any patient. Intradialytic hypotension (IDH) was recorded in 5 (38%) of 13 patients in group 1, in 3 (33%) of 9 in group 2, and in 2 (15%) of 13 patients in group 3 (p = 0.47). 4 (80%) of 5 patients in group 1 had multiple episodes of IDH. There were 0.92 +/- 1.4 episodes of IDH per patient in group 1 as compared with a rate of 0.44 +/- 0.68 per patient in group 2, and of 0.15 +/- 0.36 per patient in group 3 (p = 0.2). IDH responded to 0.9% normal saline replacement in all cases. Group 1 patients who had IDH (n = 5) were older (68 +/- 3 vs. 58 +/- 7 years, p = 0.01), had a lower diastolic blood pressure at the start of hemodialysis (59 +/- 13 vs. 83 +/- 13 mm Hg; p = 0.01), had a lower post-AMI left ventricular systolic ejection fraction (42 +/- 19 vs. 62 +/- 10%; p = 0.04), and also had a lower predialysis serum albumin level (3.6 +/- 0.4 vs. 4.1 +/- 0.4 g/dl; p = 0.09) than those who did not have IDH (n = 8). All 5 group 1 patients who had IDH (100%) had had prior AMI as compared with 2 (25%) of 8 of those who did not have IDH (p = 0.02). AMI involved the inferior myocardial wall in more (4 of 5; 80%) of the group 1 patients who had IDH as compared with those who did not have IDH (2 of 8; 25%; odds ratio = 9.5; p = 0.08; 95% confidence interval = 0.7-341.0). In group 1 patients, the time from onset of chest pain to hemodialysis did not affect the risk of IDH (p = 0.4). We conclude that a low diastolic blood pressure at onset of hemodialysis prior myocardial infarction, inferior myocardial wall involvement, advanced age, and a low predialysis serum albumin level are risk factors for the development of hypotension during the first hemodialysis session after AMI.