Randomized Intervention Treatment of Angina Trial - RITA

Description:

CABG vs. PTCA for mortality in multivessel coronary disease.

Hypothesis:

Either CABG or PTCA is a better treatment for coronary artery disease (CAD)

Study Design

Study Design:

Patients Screened: Not given
Patients Enrolled: 1,011
Mean Follow Up: 3 years

Patient Populations:

Men or women of any age.
Arteriographically proven CAD if myocardial revascularization was thought necessary on clinical grounds.
All treatment vessels must be judged to supply 20% or more of the left ventricular myocardium.

Exclusions:

>3 treatment vessels
Left-main-stem disease
Previous PTCA or CABG
Hemodynamically significant valve disease
Non-cardiac disease likely to limit long-term prognosis

Primary Endpoints:

Combined death or definite myocardial infarction (MI)

Secondary Endpoints:

Symptom and employment status, quality of life, exercise tolerance, left ventricular function

Drug/Procedures Used:

CABG, PTCA

Principal Findings:

After 2.5 years of follow-up:
There have been 34 deaths (18 CABG, 16 PTCA). The pre-defined combined primary event of death or definite myocardial infarction shows no evidence of a treatment difference (43 CABG, 50 PTCA; relative risk 0.88 [95% confidence interval 0.59-1.29]).

4% of PTCA patients required emergency CABG before discharge and a further 15% had CABG during follow-up.

Within 2 years of randomization 38% and 11% of the PTCA and CABG groups, respectively, required revascularization procedure(s) or had a primary event (p < 0.001) and repeat coronary arteriography during follow-up was four times more common in PTCA than in CABG patients (31% vs. 7%, p < 0.001).

The prevalence of angina during follow-up was higher in the PTCA group (e.g., 32% vs. 11% at 6 months) but this difference became less marked after 2 years (31% vs. 22%). Anti-anginal drugs were prescribed more frequently for PTCA patients. At 1 month CABG patients were less physically active, with greater coronary related unemployment and lower mean exercise times than the PTCA patients. Thereafter employment status, breathlessness, and physical activity improved, with no significant differences between the two treatment groups.

At 1 year mean exercise times had increased by 3 min for both groups.

Resting ejection fractions were studied in 47% of patients. At both 1 month and 6 months after randomization, there was no evidence of change in either treatment group. For instance, at 6 months the mean changes were -0.1% for the CABG group and +0.3% for the PTCA group.

The initial average cost of treating a patient randomized to PTCA was about 52% of that of CABG, but after 2 years this increased to about 80% because of the greater need for subsequent interventions.

After 3 years of follow-up:
Both PTCA and CABG produced marked improvement in all quality-of-life dimensions (energy, pain, emotional reactions, sleep, social isolation, and mobility) and aspects of daily living.

Patients with angina at two years had more quality-of-life impairment than angina-free patients, whose perceived health was similar to population norms. This reflects the close link at baseline between angina grade and quality of life. The slightly greater impairment of quality of life in PTCA compared with CABG patients is a result of their significantly higher chances of having angina, especially after 6 months.

Employment status was investigated mainly for men <60 years old. PTCA patients returned to work sooner (40% at 2 months compared with 10% of CABG patients), but the latter caught up by 5 months. After 2 years, 22% and 26% of CABG and PTCA patients, respectively, were not working for cardiac reasons. Patients with angina at 2 years were much more likely to be unemployed than those without.

Interpretation:

Recovery after CABG, the more invasive procedure, takes longer than after PTCA. However, CABG leads to less risk of angina and fewer additional diagnostic and therapeutic interventions in the first 2 years than PTCA. So far, there is no significant difference in risk of death or myocardial infarction. The impact of angina on quality of life and unemployment is greatly alleviated by PTCA or CABG. Angina is avoided more successfully with CABG, but PTCA offers a speedier return to work. Both intervention strategies then produce similar benefits for quality of life and employment over several years.

References:

1. Br Heart J 1989;62:411-4. Trial design
2. Lancet 1993;341:573-80. 2.5-year follow-up
3. Lancet 1994;344:927-30. Cost analysis
4. Circulation 1996;94:135-142. 3-year follow-up

Keywords: Coronary Artery Disease, Myocardial Infarction, Follow-Up Studies, Coronary Angiography, Quality of Life, Social Isolation, Motor Activity, Confidence Intervals, Coronary Artery Bypass


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