Coronary calcification and cardiac events after percutaneous intervention in dialysis patients.

BACKGROUND: Previous studies have described increased vascular calcification in renal dialysis patients. The clinical significance of this finding with respect to outcomes after percutaneous coronary intervention in this population is unknown. METHODS: We analysed a prospective interventional database at a single tertiary center and identified 41 dialysis patients who underwent coronary angioplasty. All studies were reviewed for the presence of coronary calcium in the target and reference vessels and compared with respect to baseline clinical factors and cardiovascular outcomes. RESULTS: The mean ages for those with and without coronary calcification were 63.6 +/- 11.0 and 67.3 +/- 11.0, respectively, P = 0.30. The groups were similar in years on dialysis, diabetes, hypertension, smoking, and measures of calcium and phosphate balance. The total cholesterol, LDL-C, HDL-C, and triglycerides were 162.5 +/- 42.3 and 202.0 +/- 54.5, P = 0.02; 94.9 +/- 39.6 and 121.2 +/- 48.1, P = 0.18; 39.3 +/- 12.4 and 47.3 +/- 12.2, P = 0.15; 157.4 +/- 100.4 and 181.3 +/- 187.4, P = 0.15, for those with and without calcification, respectively. The composite of target vessel revascularization, myocardial infarction, or death was 47.4% and 77.3% for those with and without calcification, respectively, P = 0.06. The Cox proportional hazards model, controlling for years on dialysis, showed a significant, event-free survival in those with coronary calcium seen fluoroscopically, P = 0.05. CONCLUSIONS: In dialysis patients, coronary calcification identified in the target or reference vessels is associated with lower total cholesterol and favourable interventional outcomes.

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.