Acute kidney injury after CABG versus PCI: an observational study using 2 cohorts.

BACKGROUND: Acute kidney injury (AKI) is a known complication after coronary revascularization, but few studies have directly compared the incidence of AKI after coronary artery bypass surgery (CABG) or after percutaneous coronary intervention (PCI) in similar patients. OBJECTIVES: The aim of this study was to investigate whether multivessel CABG compared with PCI as an initial revascularization strategy is associated with a higher risk for AKI. METHODS: A retrospective analysis of patients undergoing first documented coronary revascularization was conducted using 2 complementary cohorts: 1) Kaiser Permanente Northern California, a diverse, integrated health care delivery system; and 2) Medicare beneficiaries, a large, nationally representative older cohort. AKI was defined in the Kaiser Permanente Northern California cohort by an increase in serum creatinine of ≥0.3 mg/dl or ≥150% above baseline and in the Medicare cohort by discharge diagnosis codes and the use of dialysis. RESULTS: The incidence of AKI was 20.4% in the Kaiser Permanente Northern California cohort and 6.2% in the Medicare cohort. The incidence of AKI requiring dialysis was <1%. CABG was associated with a 2- to 3-fold significantly higher adjusted odds for developing AKI compared with PCI in both cohorts. CONCLUSIONS: AKI is common after multivessel coronary revascularization and is more likely after CABG than after PCI. The risk for AKI should be considered when choosing a coronary revascularization strategy, and ways to prevent AKI after coronary revascularization are needed.

ß-blocker therapy and cardiac events among patients with newly diagnosed coronary heart disease.

BACKGROUND: The effectiveness of beta-blockers for preventing cardiac events has been questioned for patients who have coronary heart disease (CHD) without a prior myocardial infarction (MI). OBJECTIVES: The purpose of this study was to assess the association of beta-blockers with outcomes among patients with new-onset CHD. METHODS: We studied consecutive patients discharged after the first CHD event (acute coronary syndrome or coronary revascularization) between 2000 and 2008 in an integrated healthcare delivery system who did not use beta-blockers in the year before entry. We used time-varying Cox regression models to determine the hazard ratio (HR) associated with beta-blocker treatment and used treatment-by-covariate interaction tests (p(int)) to determine whether the association differed for patients with or without a recent MI. RESULTS: A total of 26,793 patients were included, 19,843 of whom initiated beta-blocker treatment within 7 days of discharge from their initial CHD event. Over an average of 3.7 years of follow-up, 6,968 patients had an MI or died. Use of beta-blockers was associated with an adjusted HR for mortality of 0.90 (95% confidence limits [CL]: 0.84 to 0.96), and an adjusted HR for death or MI of 0.92 (CL: 0.87 to 0.97). The association between beta-blockers and outcomes differed significantly between patients with and without a recent MI (HR for death: 0.85 vs. 1.02, p(int) = 0.007; and HR for death or MI: 0.87 vs. 1.03, p(int) = 0.005). CONCLUSIONS: Use of beta-blockers among patients with new-onset CHD was associated with a lower risk of cardiac events only among patients with a recent MI.

Incremental prognostic information from kidney function in patients with new onset coronary heart disease.

BACKGROUND: Prognostic factors are usually evaluated by their statistical significance rather than by their clinical utility. Risk reclassification measures the extent to which a novel marker adds useful information to a prognostic model. The extent to which estimated glomerular filtration rate (eGFR) adds information about prognosis among patients with coronary heart disease is uncertain. METHODS: We studied patients in an integrated health care delivery system with newly diagnosed coronary heart disease. We developed a model of the risk of death over 2 years of follow-up and then added eGFR to the model and measured changes in C-index, net reclassification improvement, and integrated discrimination improvement. RESULTS: Almost half of the 31,533 study patients had reduced eGFR (<60 mL/min per 1.73 m(2)). Mortality was significantly higher among patients who had lower levels of eGFR, even after adjustment for baseline characteristics (P < .0001). The addition of eGFR to the prognostic model increased the C-index from 0.837 to 0.843, the net reclassification improvement by 3.2% (P < .0001), and integrated discrimination improvement by 1.3% (P = .007). CONCLUSION: Estimated glomerular filtration rate is an informative prognostic factor among patients with incident coronary heart disease, independent of other clinical characteristics.

Matrix metalloproteinase circulating levels, genetic polymorphisms, and susceptibility to acute myocardial infarction among patients with coronary artery disease.

OBJECTIVE: The aim of this study was to assess systematic differences between patients with acute myocardial infarction (MI) and patients with stable angina in matrix metalloproteinase (MMP) circulating levels and genetic polymorphisms. METHODS: We identified adults in a large integrated health care delivery system whose initial clinical presentation of coronary disease was either an acute MI or stable exertional angina. A total of 909 patients with acute MI, 466 patients with stable angina, and 1023 healthy older control subjects were genotyped. Serum levels of pro-MMP1, MMP2, MMP3, MMP9, and MMP10 were measured in 199 randomly selected patients from each group. RESULTS: At a median of 15 weeks after initial clinical presentation, higher circulating levels of MMP2 and MMP9 were independently associated with acute MI after statistical adjustment for conventional risk factors, hs-CRP levels, and cardiac medications. By contrast, none of the polymorphisms in MMP1, MMP2, MMP3, MMP9, or MMP10 was significantly associated with either acute MI compared with angina, or with coronary disease compared with controls. CONCLUSIONS: Circulating levels of MMP2 and MMP9 are independently associated with development of an acute MI rather than stable angina as the initial clinical presentation of coronary artery disease.