Journal of General Internal Medicine

, Volume 29, Issue 7, pp 1031–1039

Comparative-Effectiveness of Revascularization Versus Routine Medical Therapy for Stable Ischemic Heart Disease: A Population-Based Study

  • Harindra C. Wijeysundera
  • Maria C. Bennell
  • Feng Qiu
  • Dennis T. Ko
  • Jack V. Tu
  • Duminda N. Wijeysundera
  • Peter C. Austin
Original Research

ABSTRACT

BACKGROUND

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.

OBJECTIVE

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.

DESIGN

Observational cohort study.

PATIENTS

Stable IHD patients from 1 October 2008 to 30 September 2011, identified using a Registry of all angiography patients in Ontario, Canada.

INTERVENTION

Revascularization, defined as PCI/CABG within 90 days after index angiography.

MAIN MEASURES

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.

KEY RESULTS

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.

CONCLUSIONS

Stable IHD patients treated with revascularization had improved risk-adjusted outcomes in clinical practice, potentially due to under-treatment of medical therapy patients.

KEY WORDS

stable ischemic heart disease angioplasty medical therapy coronary artery bypass grafting comparative effectiveness 

Supplementary material

11606_2014_2813_MOESM1_ESM.pdf (513 kb)
ESM 1(PDF 513 kb)

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Copyright information

© Society of General Internal Medicine 2014

Authors and Affiliations

  • Harindra C. Wijeysundera
    • 1
    • 2
    • 3
    • 4
  • Maria C. Bennell
    • 1
  • Feng Qiu
    • 3
  • Dennis T. Ko
    • 1
    • 2
    • 3
  • Jack V. Tu
    • 1
    • 2
    • 3
  • Duminda N. Wijeysundera
    • 2
    • 3
    • 4
    • 5
  • Peter C. Austin
    • 3
  1. 1.Schulich Heart Centre, Division of Cardiology, Sunnybrook Health Sciences CentreUniversity of TorontoTorontoCanada
  2. 2.Institute of Health Policy, Management and EvaluationUniversity of TorontoTorontoCanada
  3. 3.Institute for Clinical Evaluative Sciences (ICES)TorontoCanada
  4. 4.Li Ka Shing Knowledge Institute of St. Michael’s HospitalTorontoCanada
  5. 5.Department of AnesthesiaToronto General Hospital and University of TorontoTorontoCanada

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