Emergent/early PCI has proven clinical benefits in the management of ACS. However, for patients with multivessel angiographic coronary artery disease (CAD) in the setting of chronic angina or stable ischemic heart disease (SIHD), the clinical pathway is less clear, largely due to three landmark trials.

SYNTAX: In this trial, 1,800 patients with three-vessel or left main CAD deemed equally amenable to CABG surgery or PCI with stenting were randomly assigned to either treatment.¹ At 1 year, the primary endpoint of major adverse cardiac or cerebrovascular events (MACCE) was more frequent with PCI versus CABG (17.8% vs. 12.4%; p = 0.002), largely due to need for repeat revascularization (13.5% vs. 5.9%; p < 0.001). Rates of death and MI were similar between the two groups, but stroke was significantly more likely with CABG (0.6% vs. 2.2%; p = 0.003). Thus, even with contemporary PCI techniques, CABG remains preferable for most cases of complex or extensive, multivessel CAD, while the benefits of PCI are largely restricted to those of symptom relief in patients with less extensive anatomic CAD, generally those with 1-vessel or 2-vessel angiographic CAD and in those with low or intermediate SYNTAX scores.

COURAGE: This was one of two studies to evaluate deferred revascularization, instead favoring a trial of intensive pharmacotherapy, lifestyle intervention, and secondary prevention ("optimal medical therapy" or OMT).² Patients (n = 2,287) with objective evidence of myocardial ischemia and significant coronary disease were randomly assigned to PCI plus OMT or OMT alone. During 4.6 years of follow-up, as an initial management strategy in patients, PCI did not reduce death, MI, or other major CV events when added to OMT.

BARI 2D: Performed contemporaneously with COURAGE, this trial included 2,368 diabetic patients with angiographically documented CAD who were evaluated for prompt revascularization (pre-specified PCI or CABG) plus OMT versus a strategy of delayed/no revascularization with OMT.³ At 5 years, rates of survival were similar between the prompt revascularization and OMT groups (p = 0.97) as were the rates of freedom from major CV events (p = 0.70). In looking at the types of revascularization individually, those in the CABG cohort (a higher-risk group with generally more severe CAD) did have a lower rate of the secondary endpoint of major CV events (death, MI, or stroke) as compared with OMT alone (22.4% vs. 30.5%; p = 0.01). Thus, BARI 2D buttressed the findings of the COURAGE trial and extended the observation of neutral clinical outcomes of PCI versus OMT to CAD patients with diabetes.

William E. Boden, MD, co-chair and lead investigator of the COURAGE trial, recalls the data were surprising to many interventionalists. Because PCI in stable ischemic heart disease (SIHD) is virtually identical procedurally to that performed for ACS, many had accepted the broader (but unproven) premise that PCI would achieve a dual goal in this population:

• Prevent MI and death through disease modification (i.e., improve "quantity of life")
• Reduce ischemia and relieve angina symptoms (improve "quality of life")

Based on COURAGE and BARI 2D, PCI for SIHD achieved the latter but not the former. In a recent commentary, Dr. Boden noted that patients themselves continue to have an overwhelming "therapeutic misconception," with more than 80–90% expecting reduced MI and lower risk of death after PCI, despite adequate pre-procedure "informed consent" that tries to explain otherwise.⁴

On the Other Hand Unlike PCI, the absolute survival advantage of CABG for three-vessel CAD is now supported by a number of studies. In a presentation at ACC.13, Dr. Boden summarized the results from three trials and more than 39,000 patients indicating that not only is there a significant survival advantage for CABG versus bare-metal stent (BMS), the benefit appears to increase with longer follow-up. Results similarly favor CABG compared to drug-eluting stent (DES) based on the final 5-year results of the SYNTAX trial.

As time goes on, the evidence grows stronger. There are now 16 randomized clinical trials showing no difference in death, MI, stroke, or other "hard" CV events between PCI and OMT.

Most recently, the landmark FREEDOM trial investigators randomly assigned patients with diabetes and multivessel disease to either bypass surgery or PCI with DES.5 The primary composite outcome of death, MI, and stroke at 5 years was significantly higher with PCI versus CABG (26.6% vs. 18.7%; p = 0.005), driven by significant reductions in all-cause mortality (16.3% vs. 10.9%; p = 0.049) and MI (13.9% vs. 6.0%; p < 0.001); strokes were lower in the PCI arm (2.4% vs. 5.2%; p = 0.03). When he presented the data in late 2012, Sidney Smith, MD, said "For those of us who see patients with diabetes who need revascularization, coronary artery bypass surgery for 2- or 3-vessel disease will give better results than drug-eluting stents."

In summarizing the data, Dr. Boden said:

• In patients with extensive CAD (3-vessel with or without left main disease and a high SYNTAX score), CABG is superior to PCI for CV event reduction.
• In diabetic patients with multivessel CAD, CABG is superior to PCI for CV event reduction.
• For patients with isolated left main disease, those with primarily 1- or 2-vessel disease, those who are not surgical candidates, or those who refuse surgery, PCI is a reasonable therapeutic option.
• Aggressive medical therapy and lifestyle intervention without initial PCI can be used safely in the majority of SIHD patients as the initial management strategy, thus preserving deferred PCI as an option for symptom relief or failed OMT.
• Although routine PCI plus OMT provides some advantage in terms of angina and quality of life, these differences are numerically small, not durable, and achieved only at an unattractive cost for chronic disease management.

References

1. Serruys PW, Morice MC, Kappetein AP, et al. N Engl J Med. 2009;360:961-72.
2. Weintraub WS, Spertus JA, Kolm P, et al. on behalf of the COURAGE Trial Research Group. N Engl J Med. 2008;359:677-87.
3. BARI 2D Study Group, Frye RL, August P, Brooks MM, et al. N Engl J Med.
2009;360:2503-15. 4. Boden WE. Heart. 2012;98:1757-60.
5. Farkouh ME, Domanski M, Sleeper LA, et al. N Engl J Med. 2012; 367:2375-84.

Keywords: Life Style, Secondary Prevention, Coronary Angiography, Quality of Life, Therapeutic Misconception, Disease Management, Coronary Disease, Coronary Artery Bypass


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