WASHINGTON – In patients with coronary artery disease, there is no increased risk of angina 1 year after percutaneous coronary intervention for bare metal stents relative to drug-eluting metal stents, according to data presented at Cardiovascular Research Technologies 2016.
“Angina pectoris in the first year after PCI [percutaneous coronary intervention] is remarkably common, affecting 32.3% of patients,” but “metallic stent type is not independently associated with the occurrence of angina,” reported Dr. Michael A. Gaglia Jr., an interventional cardiologist at MedStar Heart and Vascular Institute in Washington.
This conclusion was based on a study in which 8,804 patients who underwent PCI with metal stents were questioned about angina and its severity. The incidence of angina was compared for bare-metal stents relative to five drug-eluting metal stents: Cypher (sirolimus-eluting, Johnson & Johnson), Taxus Express2 (paclitaxel, Boston Scientific), Xience V (everolimus, Abbott Vascular), Promus Element (everolimus, Boston Scientific), and Resolute Integrity (zotarolimus, Medtronic).
For nearly 3 months, the cumulative incidence of angina remained tightly grouped at 5% or less across stent types. Incidence rates began climbing slowly through the first 9 months of follow-up and then more steeply at about 10 months. When depicted graphically, the incidence of angina appeared higher after placement of the Cypher stent, which was discontinued in 2011, but multivariate analysis found “no significant association between stent type and angina at 1 year after PCI,” Dr. Gaglia reported.
Although risk of angina was not correlated with type of metal stent, angina was highly correlated with risk of a major adverse cardiovascular event (MACE). When angina severity was stratified by the Canadian Cardiovascular Society system, MACE, defined as a composite of all-cause mortality, target vessel revascularization, and Q-wave myocardial infarction, occurred in 6.8% of those without angina, 10.0% of those with class 1 or 2 angina, and 19.7% of those with class 3 or 4 angina (P less than .001 for this trend) over the course of follow-up.
Independent of stent type, angina was more common in patients with a history of severe angina prior to PCI, a prior PCI, or prior coronary artery bypass grafting. A reduced likelihood of angina was independently associated with older age, male sex, a presentation of acute coronary syndrome, and a longer stented length.
Other studies have also shown that angina after PCI is associated with an increased risk of MACE relative to the absence of ischemia, but the contribution of this study is that it is the first set of data to suggest that drug eluting stents provide no advantage over bare metal stents for controlling angina, according to the authors. In the graphic representation of angina incidence for different stent types over 1-year of follow-up, four of the six lines, including the line representing bare metal stents, were essentially superimposable. In addition to the line representing angina incidence in those receiving the Cypher stent, the line representing angina incidence on the Promus Element stent climbed higher at 9 months relative to the remaining four stent types, but this line had rejoined the others at 12 months.
“Metallic coronary stents alter vessel geometry, shear stress, and hemodynamics. Stents also vary in design and architecture,” Dr. Gaglia observed. Although protection from angina is one of the major indications for the placement of stents, Dr. Gaglia emphasized that data comparing different metallic stents in regards to the incidence of angina pectoris at long-term follow-up have until this study “been lacking.”
The meeting was sponsored by the Cardiovascular Research Institute at Washington Hospital Center. Dr. Gaglia reports no relevant financial relationships. Abbott Vascular funded the study.