**2.3. Techniques of HCR**

along with the adoption of minimally invasive surgical approaches make hybrid procedures an attractive alternative to conventional surgical or interventional techniques for a wide variety of cardiovascular diseases [1–3]. Angelini et al. reported the first case series of hybrid coronary artery revascularization in 1996 [4]. Since then, along with technological advancement, hybrid procedures are currently applied not only for coronary artery disease, but also for valvular heart disease, arrhythmia, congenital heart disease, aortic diseases, and peripheral vascular

As a result of rapid evolution of transcatheter techniques, interventional cardiologists are playing a central role in the management of cardiovascular diseases. For a success of hybrid approach, a formulation of Heart Team combined with good collaboration between interventional cardiologists and cardiac surgeons is encouraged to facilitate patient management. The indications and patient selection for hybrid procedures need to be well discussed in Heart Team.

Despite the increasing use of percutaneous coronary intervention (PCI) for coronary artery disease during the past decade [5], coronary artery bypass grafting (CABG) remains the gold standard for multivessel coronary artery disease or left main disease [6]. A number of major trials such as SYNTAX [7], ASCERT [8], and FREEDOM [9] reported superior long-term sur-

The main factor of the superiority of CABG over PCI is the use of left internal mammary artery (LIMA) to left anterior descending (LAD) artery [10, 11]. The excellent long-term patency of LIMA to LAD graft has been established [12–14], whereas the long-term outcomes of other conduits such as saphenous vein graft and radial artery have been reported to be poorer than those of LIMA. The patency rates of saphenous vein grafts were 71–87% at 1-year after sur-

On the other hand, newer generation of drug-eluted stents are associated with fewer restenosis and repeat revascularization compared to conventional bare metal stents [20], and are associated with similar or even better long-term patency rates than saphenous vein grafts [11, 17, 21–23]. Thus, the combination of LIMA-LAD bypass and PCI using new generation of drug-eluting stents to non-LAD lesions takes the advantage of both procedures. The rationale of HCR is to combine the survival benefit and high patency rates of LIMA graft with the lower restenosis rates of new generation drug-eluting stents for non-LAD lesions [11, 24, 25].

HCR is applicable in patients having multivessel coronary artery disease with CABG-suitable LAD disease and PCI-suitable non-LAD disease [1, 11, 26–28]. HCR takes the most advantage in patients with comorbidities such as diabetes mellitus, obesity, chronic kidney disease, chronic occlusive pulmonary disease, and advanced age [11, 28], because these comorbidities

**2. Hybrid coronary revascularization (HCR)**

gery in previous studies [15–17], and up to 50% at 10-years [15–19].

are known to increase the risk of conventional CABG.

vival rates of CABG compared with PCI.

disease.

258 Interventional Cardiology

**2.1. Rationale of HCR**

**2.2. Indications of HCR**

Several techniques have been reported for achieving minimally invasive CABG [1]. Thoracoscopic endoscopic CABG; LIMA graft is harvested with the use of thoracoscopy through a port-access approach. The LIMA-to-LAD anastomosis is then performed by hand on the beating heart using specially designed stabilizers and retractors [2]. Robotically assisted CABG; LIMA graft is harvested with an assistance of robot followed by a hand-sewn LIMA-to-LAD anastomosis on the beating heart [3]. Totally endoscopic CABG, LIMA harvest and the anastomosis are performed endoscopically with the robot. The anastomosis can be performed on the beating heart or on cardiopulmonary bypass on an arrested heart.

HCR can be performed either as a one-staged or a two-staged procedure. A two-staged procedure is defined as a PCI and CABG performed separately by hours or days. A one-staged HCR is defined as PCI and CABG performed in a hybrid-operating room in one operative setting. The advantages of one-staged HCR include complete revascularization with minimal patient discomfort, intraoperative confirmation of LIMA-to-LAD anastomosis, and easy conversion to conventional CABG if needed [29]. However, bleeding concerns due to dual antiplatelet therapy and incomplete heparin reversal, as well as acute stent thrombosis possibility are disadvantages of one-staged HCR [11].

In a two-staged approach, there is a concern of adverse coronary events between the procedures because patients are incompletely revascularized. When PCI is preceded, CABG needs to be performed under the effect of dual antiplatelet therapy, which leads to significant bleeding risk. On the other hand, when CABG is preceded, PCI can be performed under the protection of the LIMA-to-LAD graft and the ability to verify the patency of the LIMA-to-LAD graft while avoiding the risk of bleeding due to dual antiplatelet therapy. Therefore, CABG-first strategy for two-staged HCR is preferable.

#### **2.4. Outcomes of HCR**

The surgical outcomes of previous studies regarding HCR are summarized in **Table 1**. The 30-day mortality after HCR ranged from 0 to 2.4%. LIMA patency is reported to be over 90%. The event-free survival rate ranged from 83 to 100%, whereas the incidence of major adverse cardiac and cerebrovascular events (MACCEs) ranged from 0 to 12.2%. However, the sample size of each study was relatively small.


*Note*: MACCE; major adverse cardiac and cerebrovascular events.

**Table 1.** Outcomes of hybrid coronary revascularization.

Zhu et al. performed a meta-analysis to compare the short-term outcomes of HCR with those of CABG for multivessel coronary artery disease. They found that HCR was noninferior to CABG in terms of the incidence of death, myocardial infarction, stroke, and renal failure, whereas HCR was associated with less blood transfusion and shorter length of stay in hospital [30]. Halkos et al. compared the outcomes of 147 HCR cases with matched off-pump CABG cases. They reported 5-year survival rate and the incidence of MACCE were similar between HCR and offpump CABG, whereas the need for repeated revascularization was higher in HCR group [31].
