Cumulative Adherence to Secondary Prevention Guidelines and Mortality After Acute Myocardial Infarction.

Background The survival benefit associated with cumulative adherence to multiple clinical and lifestyle-related guideline recommendations for secondary prevention after acute myocardial infarction (AMI) is not well established. Methods and Results We examined adults with AMI (mean age 68 years; 64% men) surviving at least 30 (N=25 778) or 90  (N=24 200) days after discharge in a large integrated healthcare system in Northern California from 2008 to 2014. The association between all-cause death and adherence to 6 or 7 secondary prevention guideline recommendations including medical treatment (prescriptions for ß-blockers, renin-angiotensin-aldosterone system inhibitors, lipid medications, and antiplatelet medications), risk factor control (blood pressure <140/90 mm Hg and low-density lipoprotein cholesterol <100 mg/dL), and lifestyle approaches (not smoking) at 30 or 90 days after AMI was evaluated with Cox proportional hazard models. To allow patients time to achieve low-density lipoprotein cholesterol <100 mg/dL, this metric was examined only among those alive 90 days after AMI. Overall guideline adherence was high (35% and 34% met 5 or 6 guidelines at 30 days; and 31% and 23% met 6 or 7 at 90 days, respectively). Greater guideline adherence was independently associated with lower mortality (hazard ratio, 0.57 [95% CI, 0.49-0.66] for those meeting 7 and hazard ratio, 0.69 [95% CI, 0.61-0.78] for those meeting 6 guidelines versus 0 to 3 guidelines in 90-day models, with similar results in the 30-day models), with significantly lower mortality per each additional guideline recommendation achieved. Conclusions In a large community-based population, cumulative adherence to guideline-recommended medical therapy, risk factor control, and lifestyle changes after AMI was associated with improved long-term survival. Full adherence was associated with the greatest survival benefit.

Multimorbidity is strongly associated with long-term but not short-term mortality after cardiac valve replacement.

BACKGROUND: The presence of multimorbidity is known to be related to adverse clinical outcomes. However, its association with mortality in patients undergoing cardiac valve replacement is not known. METHODS: Multimorbidity (as a continuous variable) was characterized in adults receiving cardiac valve replacement surgery between 2008 and 2012 within Kaiser Permanente Northern California based on information from health plan electronic health records. Our primary outcome was 3-year all-cause mortality after surgery. We used Cox proportional hazards regression to evaluate the independent association of each additional comorbidity with mortality. RESULTS: Among 3686 eligible patients, mean age was 67.9±13.5years and median comorbidity burden was 3 (IQR: 2). The presence of most individual comorbidities except hypertension and hyperlipidemia did not occur in isolation. The unadjusted annual incidence (per 100 person-years) of death increased with higher comorbidity burden: ≤1: 4.61 (95% CI: 3.29-6.45), 2-3: 13.7 (95% CI: 11.9-15.8), 4-5: 23.6 (95% CI: 20.6-26.9), and ≥6: 43.4(95% CI: 34.6-54.4). Advancing age, diabetes mellitus, cerebrovascular accident, heart failure, lung disease, urgent status and use of aldosterone-receptor antagonists were independently associated with an increased risk of mortality. In multivariable analyses, each additional comorbidity was significantly associated with an increased risk of long-term (adjusted hazard ratio (HR) 1.30, 95% CI: 1.22-1.39) but not short-term mortality (HR 0.92, 95% CI: 0.80-1.07). CONCLUSIONS: Our study demonstrated that multimorbidity in patients undergoing cardiac valve replacement is significantly associated with long-term but not short-term mortality.

Association of Age to Mortality and Repeat Revascularization in End-Stage Renal Disease Patients: Implications for Clinicians and Future Health Policies.

BACKGROUND: The clinical effects of age occur over an age continuum, yet age as a primary predictor is often analyzed using arbitrary age cut-points. OBJECTIVE: To assess whether transformation of a continuous variable such as age using a spline function can uncover nonlinear associations between age and cardiovascular outcomes. DESIGN: Observational retrospective cohort study in 1015 Kaiser Permanente Northern California patients with end-stage renal disease after index coronary revascularization. Age, the primary predictor, was modeled by 5 different techniques: 1) dichotomized at 65 years or older; 2) at 80 years or older (as a sensitivity analysis); 3) categorized as younger than 55 years (reference), 55 to 64, 65 to 74, and 75 years or older; 4) linear (every 5 years) variable; and 5) nonlinear by transformation into a cubic spline. Age categories were changed in a sensitivity analysis. MAIN OUTCOME MEASURES: Primary and secondary outcomes were all-cause mortality and repeat revascularization, respectively. RESULTS: Graphical assessment demonstrated that age dichotomized at either 65 years and older or 80 years and older led to loss of information. Categorized age underestimated or overestimated risk at the extremes of age. A sensitivity analysis demonstrated that an arbitrary change in the age category led to a different conclusion. Age modeled linearly adequately represented mortality risk but was suboptimal with repeat revascularization. Only the cubic spline demonstrated the nonlinear association between age and repeat revascularization. CONCLUSION: Employing the continuous variable age as a case study, we have demonstrated that the use of flexible transformations, such as spline functions, can unearth clinically meaningful associations that would not have been possible otherwise. Future research should determine whether incorporation of these methods can improve decision making at a population level.

Coronary artery bypass grafting and percutaneous coronary intervention in patients with end-stage renal disease.

OBJECTIVES: To determine the relative risks of long-term mortality between coronary artery bypass grafting (CABG) and percutaneous coronary intervention (PCI) among patients with end-stage renal disease (ESRD). METHODS: We identified 1015 patients with ESRD who underwent coronary revascularization between 1996 and 2008 within Kaiser Permanente Northern California. We obtained clinical variables from health plan databases, state death certificates and social security administration files. Our primary and secondary outcomes, respectively, were all-cause mortality and repeat revascularization. Our primary predictor was CABG compared with PCI. We used a Cox proportional hazards model for multivariable analyses. RESULTS: The mean age of CABG and PCI patients was similar (64.7 ± 10.6 and 63.4 ± 9.3, respectively, P = 0.06). The CABG group had a higher proportion of diabetics (P = 0.045), and higher nitrate use (P = 0.01). Adjusted for age, gender, race, year of index revascularization, number of vessels intervened, duration of dialysis and baseline comorbidities, patients referred for CABG during the first year had a hazard ratio (HR) of 1.16 [95% confidence interval (CI), 0.80-1.67] for mortality compared with PCI. During Years 1-5, the HR was 0.91 (95% CI, 0.63-1.33) with an overall HR of 0.73 (95% CI, 0.43-1.22). The sub-HR as calculated by the Fine-Gray competing risk model was 0.51 (95% CI, 0.31-0.85). CONCLUSIONS: As there are no randomized clinical trials in this area, our observational study adds to the growing body of literature that suggests a significant decrease in repeat revascularization with CABG and at least equivalency in long-term mortality with CABG when compared with PCI in ESRD patients.

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.

Temporal trends in mortality after coronary artery revascularization in patients with end-stage renal disease.

BACKGROUND: Recent studies that have assessed the comparative effectiveness between coronary artery bypass grafting (CABG) and percutaneous coronary intervention (PCI) in patients with end-stage renal disease (ESRD) that have included analyses of temporal trends in mortality have noted mixed results. METHODS: We conducted an observational longitudinal cohort study of all adults with ESRD undergoing CABG or PCI within Kaiser Permanente Northern California. The primary predictor, index period of revascularization, was categorized into 3 periods: 1996-1999 (reference), 2000-2003, and 2004-2008, with the primary outcome being 3-year all-cause mortality. A multivariable Cox regression model with the assumption of independent censoring was used to determine the adjusted relative risk of the primary predictor. RESULTS: Among 1015 ESRD patients, 3-year mortality showed no significant change in the 2000-2003 period but was lower during the 2004-2008 period with an adjusted hazard ratio of 0.66 (95% confidence interval: 0.49-0.88; trend test p = 0.01). No change in 30-day mortality was noted. Further adjustment for receipt of medications at baseline and after revascularization did not materially affect risk estimates. No significant interactions were observed between the type of revascularization (CABG or PCI) and the period of the index revascularization. CONCLUSIONS: Among a high-risk cohort of patients with ESRD and coronary artery disease within Kaiser Permanente Northern California who were referred for coronary revascularization by either CABG or PCI, the relative risk of mortality in the 2004-2008 period decreased by 34% compared with the 1996-1999 period, with the benefit primarily in the decrease in late mortality.

Comparative effectiveness of coronary artery bypass grafting and percutaneous coronary intervention for multivessel coronary disease in a community-based population with chronic kidney disease.

BACKGROUND: Randomized clinical trials comparing coronary artery bypass grafting (CABG) with percutaneous coronary intervention (PCI) have largely excluded patients with chronic kidney disease (CKD), leading to uncertainty about the optimal coronary revascularization strategy. We sought to test the hypothesis that an initial strategy of CABG would be associated with lower risks of long-term mortality and cardiovascular morbidity compared with PCI for the treatment of multivessel coronary heart disease in the setting of CKD. METHODS: We created a propensity score-matched cohort of patients aged ≥30 years with no prior dialysis or renal transplant who received multivessel coronary revascularization between 1996 and 2008 within a large integrated health care delivery system in northern California. We used extended Cox regression to examine death from any cause, acute coronary syndrome, and repeat revascularization. RESULTS: Coronary artery bypass grafting was associated with a significantly lower adjusted rate of death than PCI across all strata of estimated glomerular filtration rate (eGFR) (in mL/min per 1.73 m(2)): the adjusted hazard ratio (HR) was 0.81, 95% CI 0.68 to 1.00 for patients with eGFR ≥60; HR 0.73 (CI 0.56-0.95) for eGFR of 45 to 59; and HR 0.87 (CI 0.67-1.14) for eGFR <45. Coronary artery bypass grafting was also associated with significantly lower rates of acute coronary syndrome and repeat revascularization at all levels of eGFR compared with PCI. CONCLUSIONS: Among adults with and without CKD, multivessel CABG was associated with lower risks of death and coronary events compared with multivessel PCI.

Use of medications for secondary prevention after coronary bypass surgery compared with percutaneous coronary intervention.

OBJECTIVES: This study sought to compare use of evidence-based secondary preventive medications after coronary bypass surgery (CABG) and percutaneous coronary intervention (PCI). BACKGROUND: Use of cardioprotective medication after coronary revascularization has been inconsistent and relatively low in older studies. METHODS: We studied patients in a large integrated healthcare delivery system who underwent CABG or PCI for new onset coronary disease. We used data from health plan databases about prescriptions dispensed during the first year after initial coronary revascularization to identify patients who never filled a prescription and to calculate the medication possession ratio among patients who filled at least 1 prescription. We focused on angiotensin-converting enzyme inhibitors (ACEI), angiotensin receptor blockers (ARBs), beta-blockers, and statins. RESULTS: Between 2000 and 2007, 8,837 patients with new onset coronary disease underwent initial CABG, and 14,516 underwent initial PCI. Patients receiving CABG were more likely than patients receiving PCI to not fill a prescription for a statin (7.1% vs. 4.8%, p < 0.0001) or for an ACEI/ARB (29.1% vs. 22.4%, p < 0.0001), but similar proportions never filled a prescription for a beta-blocker (6.4% vs. 6.1%). Among those who filled at least 1 prescription post-revascularization, patients receiving CABG had lower medication possession ratios than patients receiving PCI for ACEI/ARBs (69.4% vs. 77.8%, p < 0.0001), beta-blockers (76.1% vs. 80.6%, p < 0.0001), and statins (82.7% vs. 84.2%, p < 0.001). CONCLUSIONS: Patients who received CABG were generally less likely than patients who received PCI to fill prescriptions for secondary preventive medications and to use those medications consistently in the first year after the procedure.