Routine angiography and revascularization procedures, if indicated, appear to offer better quality of life than conservative medical treatment for patients with chest pain and evidence of coronary artery disease, according to a new study (PDF file) in the Jan. 18, 2005 issue of the Journal of the American College of Cardiology.
“Our bottom line message is that, overall, an early interventional strategy provides small improvements in health-related quality of life without an apparent increase in risk of heart attack or death. Most of these gains appeared to have been due to improvements in angina grade,” said Joseph Kim, Ph.D., at the London School of Hygiene and Tropical Medicine.
While patients with severe angina (chest pain) or coronary artery disease routinely receive angiography, followed by angioplasty, stenting or bypass surgery if appropriate, it has not been clear how such intervention compares to drug treatment for patients with less severe disease.
“The controversy was about whether patients with a moderate risk of heart attack do better with an early interventional strategy or a more conservative strategy. Results of previous studies seemed to be inconclusive, while current American Heart Association guidelines recommend either an invasive or a conservative strategy. The RITA-3 trial was designed to assess whether patients on an interventional strategy perform better than those placed on a more conservative strategy with regard to clinical outcomes, as well as health-related quality of life.”
Patients were recruited from 45 centers across England and Scotland from Nov. 12, 1997, to Oct. 2, 2001. Patients were eligible for the study if they experienced chest pain at rest and had documented electrocardiographic or previous arteriographic evidence of coronary artery disease. Patients were randomized either to an early intervention (895 patients received maximal medical therapy plus early coronary arteriography with possible myocardial revascularization) or to a more conservative strategy (915 patients were given maximal medical therapy unless symptoms were severe enough to prompt angiography and revascularization).
Using four different measures of health status and quality of life, the researchers found that patients who were in the early intervention group generally reported better outcomes after four months. After one year, the intervention group still scored higher, but the differences had narrowed and were not all statistically or clinically significant.
Dr. Kim said the decreasing differences between the two groups were probably due to the fact that many patients in the conservative treatment group were ultimately referred to angiography and possible intervention if their symptoms were not adequately managed by drugs alone. Thus, over time, the differences between the groups became blurred. Just over 10 percent of the patients randomized to the conservative therapy group underwent a revascularization procedure during their initial hospitalization. Within one year, revascularizations had been performed in 28 percent of the patients in the conservative therapy group compared to 57 percent of the patients in the early intervention group.
“What is remarkable is that despite this crossover of patients, we observed statistically significant improvements in health-related quality of life at 4-months follow-up and to a lesser extent at 1-year follow-up,” Dr. Kim said.
The researchers wrote that these results appear to strengthen the case for early intervention.
“The public policy implications of this study are that an early intervention strategy should be recommended to reduce the occurrence of refractory angina and possibly to improve angina-related health related quality of life in patients with non–ST-segment elevation acute coronary syndrome. However, this benefit must be balanced against economic cost and clinical risk of performing an early intervention on all patients,” they wrote.
Dr. Kim noted that the researchers had to make some assumptions about the quality of life of patients at the beginning of the study, because they did not have baseline scores for all the measures. Also, he said there is some uncertainty about what some of the differences in the measured quality of life scores mean in the daily lives of patients. For instance, according to one of the questionnaires used in this study, the Seattle Angina Questionnaire, the differences between the groups after one year were too small to be considered clinically significant, based on the guideline used by the questionnaire’s developer, Dr. John Spertus.
“If one were to apply Spertus’ guideline strictly, I would have to agree with that interpretation. However, we should keep in mind that an individual’s quality of life is difficult to measure, while quality of life scores in general are difficult to interpret. I would be less inclined to place such a strict interpretation on quality of life scores,” Dr. Kim said.
Dr. Spertus, at the Mid America Heart Institute in Kansas City, Mo., who was not connected with this study, called it a “very thorough and well-conducted study” that amplifies earlier results on the clinical benefits of early intervention compared to conservative therapy for these patients with chest pain and coronary artery disease.
“It is particularly important because patients are likely to be at least concerned about their health status – their symptoms, function and quality of life – as about the longevity of their survival. Since the original report found no differences in survival or myocardial infarction, these health status data dominate the clinical decision process with respect to optimal therapy; namely that an invasive strategy appears superior,” Dr. Spertus said.
Dr. Spertus also noted that chest pain was the strongest factor in determining how patients rated their health status. He said the study design and other factors may have delayed referral to angiography for some patients who were suffering chest pain despite drug treatment. He said that choice of early intervention or conservative therapy may depend on what sort of ongoing care and options patients have to manage their chest pain.
“Thus, I believe that if patients are unlikely to have access to good medical care and close follow-up, then a routine, early invasive strategy is preferable. However, if they will have frequent, careful assessments of their angina control after discharge, then a more conservative strategy is likely to be equally effective in optimizing patients’ outcomes,” Dr. Spertus said.