Meta-analysis: Cumulative Stroke Higher with CABG vs. PCI; Late Stroke Comparable

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Percutaneous coronary intervention (PCI) is associated with a lower risk of stroke within 30 days and cumulative stroke out to 5 years compared with coronary artery bypass grafting (CABG), especially in patients with multivessel disease, unprotected left main stenosis, and diabetes, according to a meta-analysis published online November 26, 2013, ahead of print in Stroke.

Samir R. Kapadia, MD, of the Cleveland Clinic (Cleveland, OH), and colleagues looked at 80,314 patients enrolled in 57 studies (9 randomized, 48 non-randomized) published between 2001 and 2013. Slightly more than half (51.8%) underwent PCI with stenting and the remainder (48.2%) were treated with CABG. Follow-up was conducted out to 5 years as follows:

  • 1 year: 35 studies (n = 39,497)
  • 2 years: 22 studies (n = 29,389)
  • 3 years: 17 studies (n = 40,584)
  • 4 years: 9 studies (n = 21,960)
  • 5 years: 13 studies (n = 22,518)
  • > 5 years: 4 studies (n = 1,676)

Compared with CABG, PCI was linked with a lower cumulative incidence of stroke out to 5 years. Additionally, there was no statistically significant difference, despite an effect size in favor of PCI, in the cumulative incidence of stroke beyond 5 years (table 1).

Table 1. Cumulative Stroke

All Patients


95% CI

P Value

1 Year



< 0.00001

2 Years




3 Years




4 Years




5 Years




> 5 Years




Subgroup analyses of patients with multivessel disease, unprotected left main stenosis, and diabetes confirmed these results for the most part. Analyses of only randomized trials also showed a lower cumulative incidence of stroke after PCI compared with CABG at 1 year (OR 0.50; 95% CI 0.33-0.77) and 5 years (OR 0.69; 95% CI 0.52-0.93).

Stroke within 30 days (early and delayed) occurred less often after PCI than CABG (OR 0.26; 95% CI 0.20-0.35). The incidence of late stroke was similar in both treatment groups (table 2).

Table 2. Late Stroke: PCI vs. CABG



95% CI

30 Days to 1 Year



30 Days to 2 Years



30 Days to 3 Years



30 Days to 4 Years



30 Days to 5 Years



30 Days to 10 Years



No Late ‘Catch-Up’

The results suggest that there is “no late catch-up phenomenon of stroke as seen in the SYNTAX trial,” Dr. Kapadia and colleagues write. “In depth analysis of the SYNTAX trial has challenged the true risk benefit of PCI by suggesting an increase in late stroke in patients undergoing PCI,” but the present analysis shows differently, they add.

“In the SYNTAX trial, of the patients who had a stroke and survived, 68% of the CABG patients versus 47% of the PCI patients had residual deficits,” the authors report. “This suggests that in survivors of stroke after CABG, there is a higher likelihood of persistence of neurological deficits and increased morbidity.” While it was not investigated in this study due to unavailability of data, “the exceedingly high rates of disability and healthcare utilization associated with stroke after CABG should not be ignored or traded for the lower incidence of TVR after CABG.”

Stroke a ‘Procedural Issue’

In a telephone interview with TCTMD, Jeffrey W. Moses, MD, of Columbia University Medical Center/Weill Cornell Medical Center (New York, NY), commented that the study is “basically saying that the excess stroke hazard seen with CABG vs. PCI is there and it doesn’t attenuate, so it’s a procedural issue. And there’s no decrement over time.”

He added that although the meta-analysis contradicts the late catch-up phenomenon seen in SYNTAX, “if you think of biologic plausibility, there’s no reason why there should be any attenuation. . . . Obviously the exposure and the risks of a stroke are far higher with manipulating the aorta in the heart . . . whereas the trauma induced by a PCI is really limited.”

However, Sorin J. Brener, MD, of Weill Cornell Medical College (New York, NY), said he was uncertain about the collection of the late stroke data without patient-level information. “I presume that most studies report stroke within 30 days so they [may have] extracted it from 1 year [data], but these are Kaplan-Meier event rates, so I’m not particularly sure how reliable this is,” he told TCTMD in a telephone interview.

“If it were to be true, then it would be quite relevant,” he continued, adding that the researchers also claimed to collect antiplatelet therapy data but neglected to report it.

Risk Predominance Differs by Patient

Still, Dr. Moses observed, “the key here is that different individuals value the avoidance of certain risks differently and for some people, minimizing stroke may be the predominant issue in their minds. . . . Some minimal difference in long-term survival over 5 years may not have a real meaning to a patient whereas a doubling of the stroke rate might.”

Dr. Brener agreed. “We know that the benefit of survival advantage with PCI [starts somewhere] around 2 years or so,” he reported. If a patient is not going to live that long and would potentially have more strokes within the first 30 days after CABG, “I would think again whether this is a worthwhile endeavor.”

Going forward, research must focus on both “the quantity and quality of strokes,” Dr. Moses said. “The real issue would be how we attenuate it. Do we have to accept this or are there ways of mitigating it to a certain extent?” he asked, adding that exploration with embolic protection in TAVR and off-pump surgery may eventually lead to improvements.


Athappan G, Chacko P, Patvardhan E, et al. Late stroke: Comparison of percutaneous coronary intervention versus coronary artery bypass grafting in patients with multivessel disease and unprotected left main disease: A meta-analysis and review of literature. Stroke. 2013;Epub ahead of print.



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  • Drs. Kapadia, Brener, and Moses report no relevant conflicts of interest.

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