Comparative-Effectiveness of Revascularization Versus Routine Medical Therapy for Stable Ischemic Heart Disease: A Population-Based Study
- First Online:
- 337 Downloads
Randomized studies have shown optimal medical therapy to be as efficacious as revascularization in stable ischemic heart disease (IHD). It is not known if these efficacy results are reflected by real-world effectiveness.
To evaluate the comparative effectiveness of routine medical therapy versus revascularization with percutaneous coronary intervention (PCI) or coronary artery bypass grafting (CABG) in stable IHD.
Observational cohort study.
Stable IHD patients from 1 October 2008 to 30 September 2011, identified using a Registry of all angiography patients in Ontario, Canada.
Revascularization, defined as PCI/CABG within 90 days after index angiography.
Death, myocardial infarction (MI) or repeat PCI/CABG. Revascularization was compared to medical therapy using a) multivariable Cox-proportional hazard models with therapy strategy treated as a time-varying covariate; and b) a propensity score matched analysis. Post-angiography medication use was determined.
We identified 39,131 stable IHD patients, of whom 15,139 were treated medically, and 23,992 were revascularized (PCI = 15,604; CABG = 8,388). Mean follow-up was 2.5 years. Revascularization was associated with fewer deaths (HR 0.76; 95 % CI 0.68–0.84; p < 0.001) ,MIs (HR 0.78; 95 % CI 0.72–0.85; p < 0.001) and repeat PCI/CABG (HR 0.59; 95 % CI 0.50–0.70; p < 0.001) than medical therapy. In the propensity-matched analysis of 12,362 well–matched pairs of revascularized and medical therapy patients, fewer deaths (8.6 % vs 12.7 %; HR 0.75; 95 % CI 0.69–0.81; p < 0.001) , MIs (11.7 % vs 14.4 %; HR 0.84; 95 % CI 0.77–0.93 p < 0.001) and repeat PCI/CABG ( 17.4 % vs 24.1 %;HR 0.67; 95 % 0.63–0.71; p < 0.001) occurred in revascularized patients, over the 4.1 years of follow-up.
The revascularization patients had higher uptake of clopidogrel (70.3 % vs 27.2 %; p < 0.001), β-blockers (78.2 % vs 76.7 %; p = 0.010), and statins (94.7 % vs 91.5 %, p < 0.001) in the 1-year post-angiogram.
Stable IHD patients treated with revascularization had improved risk-adjusted outcomes in clinical practice, potentially due to under-treatment of medical therapy patients.
KEY WORDSstable ischemic heart disease angioplasty medical therapy coronary artery bypass grafting comparative effectiveness
- 1.Fraker TD Jr, Fihn SD, Gibbons RJ, Abrams J, Chatterjee K, Daley J, et al. 2007 chronic angina focused update of the ACC/AHA 2002 guidelines for the management of patients with chronic stable angina: a report of the American College of Cardiology/American Heart Association Task Force on Practice Guidelines Writing Group to develop the focused update of the 2002 guidelines for the management of patients with chronic stable angina. J Am Coll Cardiol. 2007;50(23):2264–74.PubMedCrossRefGoogle Scholar
- 6.Cardiac Care Network of Ontario. [http://www.ccn.on.ca/index.php]. Accessed 6 February 2013.
- 7.Cardiac Care Network (CCN) Annual Report 2010/2011. 2011.Google Scholar
- 8.Tu JV, Ko DT, Guo H, Richards JA, Walton N, Natarajan MK, et al. Determinants of variations in coronary revascularization practices. CMAJ. 2011.Google Scholar
- 13.Austin PC. Optimal caliper widths for propensity-score matching when estimating differences in means and differences in proportions in observational studies. Pharm Stat. 2010.Google Scholar
- 22.Steinberg BA, Steg PG, Bhatt DL, Fonarow GC, Zeymer U, Cannon CP, et al. Comparisons of guideline-recommended therapies in patients with documented coronary artery disease having percutaneous coronary intervention versus coronary artery bypass grafting versus medical therapy only (from the REACH International Registry). Am J Cardiol. 2007;99(9):1212–5.PubMedCrossRefGoogle Scholar
- 23.American College of Cardiology, American Heart Association, Physician Consortium for Performance ImprovementClinical Performance Measures: Chronic Stable Coronary Artery Disease. . 2003.Google Scholar