Determinants of mortality after myocardial infarction in patients with advanced renal dysfunction.

Previous studies using administrative data have shown high mortality in patients with renal failure requiring dialysis after acute myocardial infarction (AMI). There has been little investigation into the mortality after AMI in those with advanced renal disease who are not on dialysis therapy. We analyzed a prospective coronary care unit registry of 1,724 patients with ST segment elevation myocardial infarction admitted over an 8-year period at a single tertiary-care center. Those not on chronic dialysis therapy were stratified into groups based on corrected creatinine clearance, with cutoff values of 46.2, 63.1, and 81.5 mL/min/72 kg. Dialysis patients (n = 47) were considered as a fifth comparison group. Older age, black race, diabetes, hypertension, previous coronary disease, and heart failure were incrementally more common across increasing renal dysfunction strata. There were also graded increases in the relative risk for atrial and ventricular arrhythmias, heart block, asystole, development of pulmonary congestion, acute mitral regurgitation, and cardiogenic shock. Primary angioplasty, thrombolysis, and beta-blockers were used less often across the risk strata (P < 0.0001 for all trends). There was an early mortality hazard (age-adjusted relative risk, 8.76; P < 0.0001) for those with renal dysfunction but not on dialysis therapy for the first 60 months, followed by graded decrements in survival across increasing renal dysfunction strata. The excess mortality in this population appears to be mediated through arrhythmias, adverse hemodynamic events, and the lower use of mortality-reducing therapy.

How safely and for how long can warfarin therapy be withheld in prosthetic heart valve patients hospitalized with a major hemorrhage?

STUDY OBJECTIVES: To identify the risk of thromboembolism after withholding or reversing the effect of warfarin therapy following a major hemorrhage. DESIGN: Retrospective medical record review. SETTING: Tertiary-care hospital. PATIENTS: Twenty-eight patients with prosthetic heart valves receiving warfarin were hospitalized for major hemorrhage from 1990 to 1997. The mean +/- SD age was 61 +/- 11 years (15 men and 13 women). Twenty patients had St. Jude valves, 4 patients had Carpentier-Edwards bioprosthetic valves, 2 patients had Starr Edwards valves, and 2 patients had Bjork-Shiley valves. Valves were in the mitral position in 12 patients, the aortic position in 12 patients, and both mitral and aortic positions in 4 patients. The average interval from valve surgery to index bleeding was 7 years. Twenty-five patients had GI or retroperitoneal hemorrhage, 2 patients had an intracranial hemorrhage, and 1 patient had a subdural hematoma. INTERVENTIONS: Vitamin K was administered to five patients and fresh frozen plasma was given to seven patients to reverse anticoagulation. The mean duration of anticoagulation withholding was 15 +/- 4 days. MEASUREMENTS AND RESULTS: None of the patients had thromboembolic complications. There were four in-hospital deaths. Twenty-two of the 24 hospital survivors resumed warfarin therapy at hospital discharge. At 6-month follow-up, 10 of 19 patients remaining on warfarin therapy had recurrent GI bleeding. CONCLUSIONS: Thromboembolic risk is low in prosthetic heart valve patients hospitalized with major hemorrhage when their warfarin therapy is reversed or withheld. Recurrent bleeding within 6 months of the resumption of anticoagulation is common, and aggressive treatment of the bleeding source and the risk-benefit ratio of continued anticoagulation need to be considered.