Drug-eluting stents versus bilateral internal thoracic grafting for multivessel coronary disease

Coronary Artery Bypass With Multiarterial Grafting vs Percutaneous Coronary Intervention

BACKGROUND

Data comparing patients who undergo multiarterial grafting during coronary artery bypass grafting (CABG) vs percutaneous coronary intervention (PCI) in patients with multivessel coronary disease are scarce. This study addresses the relevance of using multiple arterial conduits vs PCI for appropriate patients.

METHODS

This retrospective study included all patients with coronary artery disease who underwent CABG with multiple arterial conduits or PCI. Propensity score matching was performed for baseline characteristics. Kaplan-Meier estimates, cumulative incidence, and freedom from major adverse cardiac and cerebrovascular events (MACCE) curves were performed.

RESULTS

The total patient population consisted of 3648 patients from 2011 to 2018 divided into 902 CABG patients and 2746 PCI patients. Patients were propensity matched (PCI, n = 838; CABG, n = 838). In the CABG cohort the left internal mammary artery was used in 837 patients (99.9%), the right internal mammary artery in 770 patients (92%), and radial arteries in 108 patients (12.9%). Patients in the PCI cohort had significantly higher 30-day mortality (24 [2.9%] vs 7 [0.8%], P < .01). Survival over follow-up (median, 4.9 years; range, 3.3-6.8) was better for the CABG cohort (730 [87.1%] vs 625 [74.6%], P < .01). Patients in the CABG cohort had greater freedom from MACCE (607 [72.4%] vs 339 [40.5%], P < .01). Cox multivariable regression showed that patients who underwent CABG had a significantly reduced risk of mortality (hazard ratio, 0.49; 95% confidence interval, 0.39-0.61; P < .01) and of MACCE (hazard ratio, 0.33; 95% confidence interval, 0.28-0.38; P < .01).

CONCLUSIONS

Patients with coronary artery disease who undergo CABG with multiple arterial conduits have significantly fewer major adverse events, improved survival, and reduced hospital readmissions.

Arterial Grafts for Coronary Bypass

Observational and randomized evidence shows that arterial grafts have better patency rates than saphenous vein grafts (SVGs) in coronary artery bypass grafting. Observational studies suggest that the use of multiple arterial grafts is associated with longer postoperative survival, but this must be interpreted in the context of treatment allocation bias and hidden confounders intrinsic to the study designs. Recently, a pooled analysis of 6 randomized trials comparing the radial artery with the SVG as the second conduit and the largest randomized trial comparing the use of single and bilateral internal thoracic arteries have provided apparently divergent results about a clinical benefit with the use of >1 arterial conduit. However, both analyses have methodological limitations that may have influenced their results. At present, it is unclear whether the well-documented increased patency rate of arterial grafts translates into clinical benefits in the majority of patients undergoing coronary artery bypass grafting. A large randomized trial testing the arterial grafts hypothesis (ROMA [Randomized Comparison of the Clinical Outcome of Single Versus Multiple Arterial Grafts]) is underway and will report the results in a few years.

Outcomes of off-pump coronary bypass grafting with the bilateral internal thoracic artery for left ventricular dysfunction

This study evaluated the outcomes of off-pump coronary artery bypass surgery (OPCAB) with severe left ventricular dysfunction using composite bilateral internal thoracic artery grafting. From January 2001 to December 2008, 1,842 patients underwent primary isolated OPCAB with composite bilateral internal thoracic artery grafting. A total of 131 of these patients were diagnosed with a severely depressed preoperative left ventricle ejection fraction (LVEF) (≤ 0.35). These patient outcomes were compared with the outcomes of 830 patients that had mildly or moderately depressed LVEF (0.36 to 0.59) and 881 patients with normal LVEF (>0.6). The early mortality for patients with severe LVEF was 2.3%. The 3-yr and 7-yr survival rate for patients with severe LV dysfunction was 86.0% and 82.8%, respectively. Multivariate analysis showed that severe LV dysfunction EF increased the risk of all-cause death (P=0.012; hazard ratio [HR],2.14; 95% confidence interval [CI],1.19-3.88) and the risk of cardiac-related death (P=0.008; HR,3.38; 95% CI, 1.37-8.341). The study identified positive surgical outcomes of OPCAB, although severe LVEF was associated with two-fold increase in mortality risk compared with patients who had normal LVEF.

SYNTAX-justified trend toward restricting coronary artery bypass grafting to more serious cases

OBJECTIVE

Since drug-eluting stents (DESs) appeared in Japan, coronary artery bypass grafting (CABG) has been indicated for more severe lesions. To understand the implications of this trend, we compared SYNTAX scores in two groups of patients treated with CABG before and after DESs approval.

METHODS

Consecutive CABG patients during January 2001-July 2003 (pre-DES era patients, n = 160) and January 2008-July 2010 (DES era patients, n = 103) were included. The SYNTAX scores of both groups were compared and a cardiologist retrospectively re-evaluated coronary angiograms to determine whether CABG or percutaneous coronary intervention (PCI) would be recommended under current standards.

RESULTS

SYNTAX scores were significantly higher in DES era group compared with pre-DES era group (33.3 ± 10.6 vs. 28.1 ± 10.6, p < 0.01). Percutaneous coronary intervention would be the preferred treatment option in 66 (41 %) of pre-DES patients, whose SYNTAX scores were significantly lower than those of patients who were considered good candidates for CABG (21.9 ± 9.3 vs. 32.5 ± 9.1, p < 0.01).

CONCLUSIONS

Although CABG is now being performed in intermediate-to-highly complex cases, DES era outcomes, including operative mortality and early graft failure, have not worsened in comparison to the pre-DES era.

Percutaneous coronary intervention versus coronary-artery bypass grafting for severe coronary artery disease

BACKGROUND

Percutaneous coronary intervention (PCI) involving drug-eluting stents is increasingly used to treat complex coronary artery disease, although coronary-artery bypass grafting (CABG) has been the treatment of choice historically. Our trial compared PCI and CABG for treating patients with previously untreated three-vessel or left main coronary artery disease (or both).

METHODS

We randomly assigned 1800 patients with three-vessel or left main coronary artery disease to undergo CABG or PCI (in a 1:1 ratio). For all these patients, the local cardiac surgeon and interventional cardiologist determined that equivalent anatomical revascularization could be achieved with either treatment. A noninferiority comparison of the two groups was performed for the primary end point--a major adverse cardiac or cerebrovascular event (i.e., death from any cause, stroke, myocardial infarction, or repeat revascularization) during the 12-month period after randomization. Patients for whom only one of the two treatment options would be beneficial, because of anatomical features or clinical conditions, were entered into a parallel, nested CABG or PCI registry.

RESULTS

Most of the preoperative characteristics were similar in the two groups. Rates of major adverse cardiac or cerebrovascular events at 12 months were significantly higher in the PCI group (17.8%, vs. 12.4% for CABG; P=0.002), in large part because of an increased rate of repeat revascularization (13.5% vs. 5.9%, P<0.001); as a result, the criterion for noninferiority was not met. At 12 months, the rates of death and myocardial infarction were similar between the two groups; stroke was significantly more likely to occur with CABG (2.2%, vs. 0.6% with PCI; P=0.003).

CONCLUSIONS

CABG remains the standard of care for patients with three-vessel or left main coronary artery disease, since the use of CABG, as compared with PCI, resulted in lower rates of the combined end point of major adverse cardiac or cerebrovascular events at 1 year. (ClinicalTrials.gov number, NCT00114972.)

Simultaneous "hybrid" percutaneous coronary intervention and minimally invasive surgical bypass grafting: feasibility, safety, and clinical outcomes

Surgical and percutaneous coronary artery intervention revascularization are traditionally considered isolated options. A simultaneous hybrid approach may allow an opportunity to match the best strategy for a particular anatomic lesion. Concerns regarding safety and feasibility of such an approach exist. We examined the safety, feasibility, and early outcomes of a simultaneous hybrid revascularization strategy (minimally invasive direct coronary bypass grafting of the left anterior descending [LAD] artery and drug-eluting stent [DES] to non-LAD lesions) in 13 patients with multivessel coronary artery disease that underwent left internal mammary artery to LAD minimally invasive direct coronary bypass performed through a lateral thoracotomy, followed by stenting of non-LAD lesions, in a fluoroscopy-equipped operating room. Assessment of coagulation parameters was also undertaken. Inhospital and postdischarge outcomes of these patients were compared to a group of 26 propensity score matched parallel controls that underwent standard off-pump coronary artery bypass. Baseline characteristics were similar in both groups. All hybrid patients were successfully treated with DES and no inhospital mortality occurred in either group. Hybrid patients had a shorter length of stay (3.6 +/- 1.5 vs 6.3 +/- 2.3 days, P < .0001) and intubation times (0.5 +/- 1.3 vs 11.7 +/- 9.6 hours, P < .02). Despite aggressive anticoagulation and confirmed platelet inhibition, hybrid patients had less blood loss (581 +/- 402 vs 1242 +/- 941 mL, P < .05) and decreased transfusions (0.33 +/- 0.49 vs 1.47 +/- 1.53 U, P < .01). Six-month angiographic vessel patency and major adverse cardiac events were similar in the hybrid and off-pump coronary artery bypass groups. A simultaneous hybrid approach consisting of minimally invasive coronary artery bypass grafting with left internal mammary artery to LAD combined with revascularization of the remaining coronary targets using percutaneous coronary artery intervention with DES is a feasible option accomplished with acceptable clinical outcomes without increased bleeding risk.

Impact of "off-label" utilization of drug-eluting stents on clinical outcomes in patients undergoing percutaneous coronary intervention

The utilization of drug-eluting stents (DES) in "real world" practice has deviated from Food and Drug Administration-approved indications. Safety concerns have arisen from recent reports that suggested increased mortality and nonfatal myocardial infarction (MI) with DES usage. Little is known about the clinical outcomes of patients undergoing intracoronary DES implantation for unapproved indications as a group compared with outcomes after bare metal stent (BMS) placement. The clinical outcomes of 546 patients undergoing DES implantation for >or=1 non-Food and Drug Administration-approved ("off label") indication since the approval of the device were assessed. The group was then matched by propensity score with 546 patients receiving BMSs prior to DES approval for the same indications. The primary endpoint was major adverse cardiac events (cardiac death, nonfatal Q-wave myocardial infarction [MI], and target vessel revascularization) at 12 months. Baseline clinical and angiographic characteristics were well matched between BMS and DES groups. The use of debulking devices was higher in the BMS group. Patients in the BMS group were more likely to be treated with larger diameter and shorter stents. There was no significant difference in the rate of in-hospital and 30-day adverse cardiac events. At 12 months, the primary endpoint of major adverse cardiac events was significantly reduced in the DES group (23.6% vs 16.7%, p=0.004), driven by reductions in the need for repeat revascularization (target lesion revascularization: 16.4% vs 7.8%, p<0.001; target vessel revascularization: 20.2% vs 13.1%, p=0.003). There was no significant difference in freedom from cardiac death or nonfatal Q-wave MI between groups (p=0.27). In conclusion, the utilization of DES for non-Food and Drug Administration-approved indications proved to be efficacious and safe when compared with a BMS cohort matched by propensity score. The advantage for DES was driven by reductions in repeat revascularization. "Off-label" DES use was not associated with increased rates of cardiac death and nonfatal MI at 12 months.

Techniques and Benefits of Multiple Internal Mammary Artery Bypass at 20 Years of Follow-Up

BACKGROUND

In patients with multivessel coronary artery disease, performing multiple internal mammary artery (MIMA) grafts to two coronary systems during coronary artery bypass grafting (CABG) improves clinical outcome. Few databases have decades of follow-up, however, and the optimal configuration is still in question. The purpose of this study was to assess 20-year clinical benefits of MIMA grafting and to evaluate the possible effects of two different MIMA configurations.

METHODS

From 1984 to 1986, 867 patients with multivessel coronary disease underwent CABG. Single (SIMA) IMA grafts were used in 490 and multiple (MIMA) IMA grafts in 377, along with concomitant saphenous veins. Generally, MIMAs were placed to the two largest coronary systems. Among baseline characteristics, only smoking, diabetes, and hypertension were significantly higher for MIMA versus SIMA. Multivariable Cox model analysis was used to assess outcome differences between groups.

RESULTS

During a median follow-up of 20 years, the composite of mortality, myocardial infarction, percutaneous coronary intervention, and redo CABG was significantly reduced after MIMA versus SIMA (p = 0.013). Event-free survival was extended by almost 1 year (p = 0.018), and redo CABG was reduced by 59% (p = 0.005). A comparison within the MIMA group was made between 235 patients receiving IMA grafts to left anterior descending/left circumflex territories versus 122 with grafts to left anterior descending/right coronary artery systems. No significant difference in composite outcome was observed between these configurations (p = 0.88).

CONCLUSIONS

These data confirm the clinical benefits of MIMA grafting in multivessel coronary disease to 20 years of follow-up. As long as MIMAs are placed to the two largest coronary systems, no significant differences in long-term results are evident between left anterior descending/left circumflex and left anterior descending/right coronary artery configurations.

Regulatory issues facing the development of drug-eluting stents: a US FDA perspective

Coronary drug-eluting stents (DES) are a breakthrough technology that has changed the standard of care for many patients undergoing percutaneous intervention for coronary artery disease. Initial trials of two DES demonstrated significant clinical benefit with respect to the need for reintervention when compared with bare metal stents. However, more recent studies of DES involve in-patients with more complex disease, such as bifurcation lesions, chronic total occlusions and multiple-vessel disease. Additionally, DES are now being evaluated in patients previously only considered for surgical intervention. Assessment of DES in these complicated patient populations can lead to challenges in trial design, but the US FDA is willing to consider alternative clinical trial designs and statistical analysis plans. Other complex issues associated with DES include duration of clinical trials to determine safety, and the appropriate dose and duration of concomitant antiplatelet therapy. Finally, the FDA acknowledges that DES are complex products to produce and we believe that through interaction with the FDA during development, difficulties with test methodologies, animal studies and clinical trial designs can be addressed. The future of DES likely involves new stent and carrier materials, including biodegradable materials and new drugs and biologicals. The FDA anticipates continued collaboration with physicians, manufacturers, academic institutions and professional societies.