A hybrid coronary revascularization procedure that combines off-pump left internal mammary artery (LIMA) grafting with percutaneous coronary intervention (PCI) showed good results at 1 year after surgery, but nonetheless showed a rate of adverse events that may raise questions about the procedure.
In a study published in the November issue of the Journal of Thoracic and Cardiovascular Surgery, a team of investigators from Aarhus University Hospital in Denmark reported high rates of graft patency and low rates of death and stroke with the procedure 1 year after a series of 100 operations (J Thorac Cardiovasc Surg. 2015;150:1181-6).
“The high left internal mammary artery graft patency rate and low risk of death and stroke at 1 year seem promising for the long-term outcome of this revascularization strategy,” said Dr. Ivy Susanne Modrau and colleagues.
The single-center study evaluated 1-year clinical and angiographic results of 100 consecutive trial patients with multivessel disease who had the hybrid procedure between October 2010 and February 2012. “The rationale of hybrid coronary revascularization is to achieve the survival benefits of the LIMA to LAD (left anterior descending artery) graft with reduced invasiveness to minimize postprocedural discomfort and morbidity, in particular the risk of stroke,” Dr. Modrau and colleagues said.
The study used the LIMA to LAD graft performed off-pump through a reversed J-hemisternotomy “We chose this technique because of its excellent exposure of the heart, technical ease, low risk of complicating chronic pain, and applicability in virtually all patients,” Dr. Modrau said. Eighty-nine patients had surgery prior to PCI and 11 had PCI prior to surgery.
The primary endpoint was rate of major adverse cardiac or cerebrovascular events (MACCE), the composite of all-cause death, stroke, myocardial infarction, and repeat revascularization by PCI or coronary artery bypass grafting at 1 year. Secondary endpoints included individual components and status of stent and graft patency on angiography.
Overall, 20 patients met the 1-year primary endpoint of MACCE. One patient died, one other had a stroke, and three had heart attacks. Sixteen patients had repeat revascularization procedures, eight performed during the index hospitalization. Graft patency was 98% after 1 year.
Dr. Modrau and coauthors noted the MACCE rate of 20% “was higher than expected,” and certainly higher than results in the SYNTAX study (17.8% in the PCI group and 12.4% in the coronary artery bypass grafting [CABG] group) (Euro. Intervention. 2015;10:e1-e6). One possible reason the Danish investigators cited for higher than expected MACCE rates was that they may be attributed to the learning curve involved with LIMA grafting and the use of early angiography possibly revealing “clinically silent LIMA graft dysfunction due to technical errors.”
The number of repeat revascularizations in the study was more in line with the SYNTAX study: 7% in the Aarhus University study and 6% in the SYNTAX CABG group. However, a meta-analysis of six studies with 1,190 patients reported 1-year repeat revascularization rates of 3.8% after a hybrid procedure and 1.4% after CABG (Am Heart J. 2014;167:585-92).
Ultimately, the safety and efficacy of the hybrid revascularization approach will require long-term follow-up data and head-to-head comparison with conventional CABG and PCI in clinical trials. “Meanwhile, LIMA patency, the cornerstone of surgical revascularization, may be used as a surrogate endpoint for long-term survival after HCR,” Dr. Modrau and coauthors said.
They reported having no disclosures.