Watchful Waiting Prevails for Most With Stable Angina

Stable angina symptoms disappeared over time for many medically-treated patients without requiring medication changes or a revascularization procedure, according to CLARIFY registry data.

Among patients who had stable coronary artery disease (CAD) and angina, 39.6% had symptoms resolve at 1 year without coronary revascularization. By 5 years, 45.8% of patients were alive, event-free, and angina-free, reported Philippe Gabriel Steg, MD, of Hôpital Bichat in Paris, and colleagues.

The vast majority (84.4%) of individuals who had baseline angina controlled at 5-year follow-up had no changes in medication or revascularization. Only 11% had received increased antianginal treatment, and 4.5% had coronary revascularization.

“As most patients with angina are likely to experience resolution of symptoms, and as there is no demonstrated outcome benefit to routine revascularization, this study emphasizes the value of conservative management of stable CAD,” the authors concluded in their paper published online in Circulation.

“This is an important study and will help us evaluate and treat these patients with optimal medical therapy, and reserve revascularization for those with ongoing persistent angina,” commented Roxana Mehran, MD, of Icahn School of Medicine at Mount Sinai in New York City, who was not involved with the research.

The CLARIFY registry comprised 32,691 stable CAD patients, 22.1% of whom reported angina at baseline. Use of secondary prevention drugs was high in this population.

Angina was linked to clinical outcomes, as independent predictors of cardiovascular death or MI at 5 years included persistence of baseline angina (adjusted HR 1.32, 95% CI 1.12-1.55) and incidental occurrence of angina (adjusted HR 1.37, 95% CI 1.11-1.70) after 1 year of conservative management.

The good news for people who had angina resolve within a 1 year on conservative management: they were not at higher risk of cardiovascular death or MI than those who never experienced angina (adjusted HR 0.97, 95% CI 0.82-1.15).

“Hopefully, the results will reassure physicians and patients that, in general, there is no need to rush to revascularization in patients with stable angina, and in fact, it would make sense in the majority of cases to wait and see if the symptoms go away on their own (assuming there is excellent background medical therapy being utilized) or get better with anti-anginal medications,” according to Deepak Bhatt, MD, MPH, of Brigham and Women’s Hospital and Harvard Medical School, in an email to MedPage Today.

“Most patients will do fine with that approach. For those who do not, they are higher risk patients and revascularization would be appropriate. These findings really are in keeping with what contemporary guidelines would tell us to do,” said Bhatt, who was also not involved with the study.

Regression of symptoms over time in stable angina has been documented in past trials, including the ISCHEMIA trial that showed symptom improvement to be the principal benefit of routine invasive management versus optimal medical therapy alone in stable CAD.

“The frequency of resolution of angina in the first year suggests that trials testing antianginal drugs may need to incorporate a longer run-in period than the short 1- to 4-week duration frequently used,” the CLARIFY group wrote.

“Furthermore, it shows that medical treatment and disease-modifying interventions may take some time to be effective and relieve symptoms, and the relatively low event rate of patients with stable CAD allows a period of watchful waiting before failure of medical management is declared,” the authors added.

CLARIFY participants were enrolled in 2009-2010 in 45 countries. The relatively low-risk population averaged 64.2 years of age, and the group with angina at baseline had disproportionately more women (28.5% vs 20.7% of peers with no angina, P<0.001).

Among those who did opt for coronary revascularization, angina was more likely to be resolved after surgery than after percutaneous coronary intervention (74.6% vs 44.6%, P<0.001).

The retrospective, observational analysis was inherently subject to potential biases and confounding.

“Resolution of angina may reflect limitation of physical activity in some patients,” the investigators cautioned. “However, the association of angina resolution with improvement in outcomes suggests that the former is not entirely explained by self-restriction of the patients.”

Moreover, outcomes were not adjudicated, Steg’s team acknowledged.

A lot more work needs to be done around angina, Bhatt commented. “Several trials and registries have now taught us that there are several different causes of angina (epicardial, microvascular, non-cardiac, etc.), and that we need to figure out how to target the right therapies (such as revascularization) to the patients most likely to benefit and not use a shotgun approach.”

Steg and colleagues highlighted their finding that 33.9% of patients with angina at baseline still had anginal symptoms at 5 years, “reflecting the unmet need for new more effective antianginal therapy.”