Getting beta-blockers after percutaneous coronary intervention (PCI) did not improve outcomes for older patients with stable angina, an observational study found.
At 3-year follow-up after coronary angioplasty — in patients with no prior myocardial infarction (MI), systolic heart failure, or left ventricular ejection fraction below 40% — adverse event rates were similar among those with and without beta-blocker prescriptions upon multivariable adjustment:
- Mortality (14.0% versus 13.3%, HR 1.00, 95% CI 0.96-1.03)
- MI (4.2% versus 3.9%, HR 1.00, 95% CI 0.93-1.07)
- Stroke (2.3% versus 2.0%, HR 1.08, 95% CI 0.98-1.18)
- Revascularization (18.2% versus 17.8%, HF 0.97, 95% CI 0.94-1.01)
“This lack of improvement in outcomes associated with beta-blocker use at discharge among a small subset of stable angina patients ≥65 years of age undergoing elective PCI are not surprising and remain broadly consistent with other recently reported analyses,” reported Valay Parikh, MD, of Staten Island University Hospital in New York, and colleagues online in JACC: Cardiovascular Interventions.
Meanwhile, heart failure readmission was more likely for those discharged on beta-blockers (8.0% versus 6.1%, HR 1.18, 95% CI 1.12-1.25).
The American College of Cardiology/American Heart Association guidelines strongly recommend beta-blockers in patients with prior MI or systolic heart failure. Ever since the COURAGE trial, patients with stable angina have been speculated to benefit from them as well, according to the authors.
“However, the evidence supporting the benefits of beta-blockers in stable coronary artery disease [CAD] patients without prior MI or systolic heart failure undergoing elective PCI, especially in the era of contemporary medical therapy, remains scarce. There are no randomized control trials addressing this issue directly, and previous nonrandomized observational studies are limited with smaller size and/or varied inclusion criteria.”
Even so, beta-blockers were increasingly prescribed over the course of Parikh’s study period, rising from 66% in the first quarter of 2005 to 74% in first quarter of 2013 (P<0.001).
During this time, “the treating physicians of this patient cohort would have felt more confident deferring PCI because the coronary stenoses were not hemodynamically significant by fractional flow reserve measurement,” suggested Anthony G. Nappi, MD, of Albany Medical College, N.Y., and William E. Boden, MD, of the VA New England Healthcare System in Boston.
“Theoretically, this might have resulted in more aggressive treatment and more beta-blocker prescriptions as part of the optimal medical therapy regimen for residual CAD,” they wrote in an accompanying editorial.
“This study along with others, raises questions about the continued role of beta-blocker usage in patients with CAD undergoing PCI,” the duo concluded, adding that it seems “increasingly difficult” to justify the strong recommendations for beta-blocker use in patients with stable ischemic heart disease.
For Parikh’s study, patient data came from linking the National Cardiovascular Data Registry (NCDR) CathPCI Registry with Medicare data. The 755,215 participants were at least 65 years of age and all underwent elective PCI between 2005 and 2013.
Short-term outcomes were similar to the 3-year findings: No difference in the frequency of adverse events was found between groups, with the exception of more rehospitalizations for heart failure among patients prescribed beta-blockers (0.9% versus 0.4%, HR 1.70, 95% CI 1.43-2.02).
That the study on older adults depended on linked Medicare data meant that only 16.7% of the NCDR population was actually included in the study. “Thus our outcomes data cannot be extrapolated to younger patients, or the majority of patients that did not have linkage to the CMS database for post-discharge outcomes,” Parikh’s group acknowledged.
Importantly, they also did not have access to drug claims data. “Our data could not account for lack of compliance, use of suboptimal dosing, type of beta-blocker, and changes in beta-blocker use pattern over time (along with the use of other post-discharge antianginals and other medications). This precludes us from ascertaining how actual treatment and compliance may have influenced the results.”
Limitations aside, the investigators found that 71.4% of their cohort received a prescription for beta-blockers. This group tended to be younger and have a history of hypertension, diabetes, high cholesterol, smoking, dialysis, and prior angioplasty. There were also more women among beta-blocker recipients.
These baseline imbalances meant that “beta-blockers may have provided relative benefit to these patients,” Parikh and colleagues noted after all.
“The patients prescribed with beta-blockers had higher prevalence of traditional risk factors for atherosclerotic cardiac events and despite that there was no significant increase in mortality and morbidity observed. There is a probability that these patients may have had higher event rates if they were not prescribed beta-blockers. It is possible that beta-blockers provide beneficial effects, but the magnitude may be less compared to following an acute coronary syndrome.”
“One may interpret these data from the perspective that the use of beta-blocker therapy was effective therapeutically, because the patients in that group did not have a higher incidence of ischemic events,” the editorialists agreed.
Parikh, Nappi, and Boden reported no relevant conflicts of interest.
Study co-authors disclosed relationships with Eli Lilly, Sanofi, Daiichi-Sankyo, the American College of Cardiology, the American Heart Association, the Familial Hypercholesterolemia Foundation, Elsevier Publishers, Janssen Pharmaceuticals, Amgen, Merck, AstraZeneca, and Gilead.
JACC: Cardiovascular Interventions
Motivala AA, et al “Predictors, trends, and outcomes (among older patients ≥65 years of age) associated with beta-blocker use in patients with stable angina undergoing elective percutaneous coronary intervention: insights from the NCDR registry” JACC Cardiovasc Interv 2016; 9: 1639-48.
JACC: Cardiovascular Interventions
Nappi AG and Boden WE “Should beta-blockers continue to be used in post-percutaneous coronary intervention patients without myocardial infarction” JACC Cardiovasc Interv 2016; 9 :1649-51.