A revascularization strategy of minimally invasive bypass grafting followed by PCI is feasible and safe for selected patients with multivessel disease, according to results of a small randomized trial published in the November 2014 issue of JACC: Cardiovascular Interventions.

“[By] combining the lesser invasiveness of PCI to non-LAD lesions with the durability and longevity of minimally invasive [left internal mammary artery (LIMA)] grafting to the LAD, [hybrid revascularization] may be the procedure of choice for many,” suggests an accompanying editorial.

Findings from the POL-MIDES (HYBRID) study were originally presented at the Transcatheter Cardiovascular Therapeutics scientific symposium in October 2013.

Mateusz Tajstra, MD, PhD, and colleagues from the Medical University of Silesia (Zabrze, Poland), randomized 200 patients with an obstructed LAD and a critical lesion (> 70%) in at least 1 other major epicardial vessel who were amenable to CABG and PCI to conventional surgical revascularization (n = 102) or hybrid revascularization consisting of minimally invasive direct coronary bypass of the LAD followed by PCI (n = 98). In all cases, the LAD artery was grafted using the LIMA.

Demographic, clinical, angiographic, and procedural characteristics were well balanced between the groups. About 4 clinically significant lesions were treated per patient in each group. The mean SYNTAX scores were also similar between the hybrid and CABG groups (23.4 and 22.8; P = .48). In the hybrid arm, mean time between bypass and PCI was 21 hours; dual antiplatelet therapy was recommended for at least 1 year.

Vast Majority Received Planned Procedures

In terms of feasibility (primary endpoint), 93.9% of patients in the hybrid group underwent complete procedures. Six patients were converted to full sternotomy, and 2 cases were emergent: 1 involved hemodynamic instability and ventricular tachycardia and the other significant bleeding that was difficult to manage endoscopically. In both instances, the early and late outcomes were unaffected, the authors say.

There were no differences between the groups in in-hospital outcomes. At 12 months, Kaplan-Meier estimates of MACE (death, MI, stroke, TVR, and major bleeding)-free survival were similar between the CABG and hybrid arms (92.2% and 89.8%; log-rank P = .54). Nor were there differences in cumulative rates of MACE or the individual endpoints (table 1).

At 12-month angiographic follow-up, there was no difference between the CABG and hybrid groups in LAD graft patency (93% and 94%; P = .74) or stenosis ≥ 70% (5% and 1%; P = .36). Other grafts in the CABG arm showed 79% patency and 2% stenosis, while in the hybrid arm rates of in-stent occlusion and stenosis ≥ 50% were 5.1% and 7.5%, respectively. The HYBRID patency score—the ratio of grafted or stented arteries free of stenosis and/or occlusion to the total number of treated arteries—was higher in those treated with hybrid revascularization compared with CABG (90% vs 81%; P = .01).

The authors say this first randomized trial of hybrid revascularization shows that the strategy is feasible in select patients with multivessel disease, and that minimally invasive direct CABG using the LIMA to treat the LAD as the first stage is not associated with an increase in adverse events.

Need Grows With Aging Population

Moreover, the need for a safer, less invasive approach to multivessel disease is increasing as the population referred for CABG grows older and accumulates comorbidities, Dr. Tajstra and colleagues observe. Hybrid revascularization combines the long-term durability of a LIMA-to-LAD graft with the lower rates of stenosis in other lesions that comes with DES implantation rather than saphenous vein grafting.

However, the investigators note, uptake of this approach has been hampered by several concerns:

• Need for close cooperation between surgeons and interventionalists

• Complicated logistics of timing and sequencing the procedures

• Potential complications from aggressive antiplatelet/anticoagulant therapy for PCI

• High risk at the surgical stage, especially in unstable patients with multivessel disease and critical stenoses in non-LAD segments

• Difficult endoscopic technique required to harvest the LIMA

Advantages of a CABG-First Strategy

In their editorial, John D. Puskas, MD, MSc, Amit Pawale, MD, and Samin K. Sharma, MD, all of the Icahn School of Medicine at Mount Sinai (New York, NY), note that the study’s bypass-first approach allows for the assessment of LAD patency to be followed by revision or reintervention if necessary. It also gives time for perioperative bleeding to be stopped before administration of high-dose antiplatelet agents for PCI, which can then be performed with the benefit of a revascularized LAD territory, they add.

Moreover, hybrid revascularization lends itself to a surgical technique that avoids manipulation of the ascending aorta, thereby minimizing stroke risk, which is “‘the Achilles’ heel of CABG historically,” the editorialists observe.

Research on hybrid revascularization may best be targeted to “patients with less extensive, hybrid-eligible coronary anatomy referred for either multivessel PCI or surgical coronary revascularization,” Dr. Puskas and colleagues write. These patients, who fall into the “ambiguous zone” in terms of SYNTAX score risk, may have better outcomes with CABG yet often choose PCI to avoid the rigors of sternotomy, they add.

“We look forward to [the authors’] report of the quality of life assessment and longer-term clinical follow-up as well as the cost-effectiveness from this important trial,” the editorialists conclude.

Sources:

1. Gąsior M, Zembala MO, Tajstra M, et al. Hybrid revascularization for multivessel coronary artery disease. J Am Coll Cardiol Intv. 2014;7:1277-1283.

2. Puskas JD, Pawale A, Sharma SK. Hybrid coronary revascularization: a new treatment paradigm for selected patients with multivessel coronary artery disease [editorial]. J Am Coll Cardiol Intv. 2014;7:1284-1286.

• Drs. Tajstra, Pawale, and Sharma report no relevant conflicts of interest.

• Dr. Puskas reports serving as a national principal investigator of a National Heart, Lung, and Blood Institute-funded study of hybrid coronary revascularization.

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