Download this article's Factoid (PDF & PPT for Gold Subscribers) 

Patients with unprotected left main disease who receive percutaneous coronary intervention (PCI) are more than twice as likely to be rehospitalized within 4 years as those who undergo coronary artery bypass grafting (CABG), according to a Korean registry study published online March 3, 2014, ahead of print in the American Journal of Cardiology. The higher readmission risk after PCI is mainly due to more frequent need for repeat revascularization.

In a prospective observational study, Seung-Jung Park, MD, PhD, of Asan Medical Center (Seoul, South Korea), and colleagues evaluated data from 1,352 registry patients enrolled in the PRECOMBAT trial, who were randomized to receive PCI (n = 783) or CABG (n = 569).

Over a median follow-up of 48.7 months, the risk of hospital readmission was almost twofold higher for PCI vs CABG patients (HR 2.04; 95% CI 1.54-2.69; P < 0.001), with 26.3% of PCI patients vs 14.8% of CABG patients experiencing at least one hospital readmission (P < 0.001).

Readmissions Driven by Repeat Revascularization

The most common reason for readmission of PCI patients was repeat revascularization, with 40.5% undergoing a procedure vs 13.2% of the CABG group (P < 0.001). In the CABG group, non-cardiac conditions were most frequently responsible for repeat hospitalizations, with 48.2% of patients being readmitted for this reason vs 32%  in the PCI group (P = 0.13).

Higher rates of revascularization for PCI patients extended to both left main (HR 9.04) and non-left main (HR 4.87) locations as well as to those with ischemic signs or symptoms (HR 5.10; all P < 0.001).

Additionally, PCI was associated with a higher risk of non-revascularization-related readmission (HR 1.6; P < 0.001).

Although the rate of first readmission was higher for PCI patients compared with CABG patients (HR 2.09; 95% CI 1.62-2.69; P < 0.001), no differences were seen between the groups for second and third readmissions. The higher rate of readmission for PCI was observed across all 3 Syntax score terciles.

On multivariate analysis, PCI (HR 1.82; 95% CI 1.42-2.33; P < 0.001) and chronic renal failure (HR 2.26; 95% CI 1.06-4.83; P = 0.035) were independent predictors of readmission. 

 “Although the readmission rate of the PCI group was higher during the entire follow-up period, the difference was most conspicuous between 3 and 27 months, with the first 9 months of this period showing the greatest difference,” the authors say.

PCI Readmissions a Trade-off

In a telephone interview with TCTMD, Jeffrey W. Moses, MD, of NewYork-Presbyterian Hospital/Columbia University Medical Center (New York, NY), called the overall results reassuring. “We know there is a slightly higher need for revascularization with PCI,” he said, but “being readmitted to the hospital is the trade-off for undergoing a minimally invasive procedure.” 

Similarly, Fred Leya, MD, of Loyola University Medical Center (Maywood, IL), said the researchers “documented a natural and expected occurrence of restenosis.” When initial angioplasty is successful, restenosis has been shown to occur about 10% percent of the time 9 months to a year afterward, he told TCTMD in a telephone interview.

Fortunately, revascularization is not burdensome and can often be done overnight or in an ambulatory setting, Dr. Moses commented, noting that in the PRECOMBAT trial patients who received PCI had rates of death and MI similar to those who underwent CABG. 

In addition, Dr. Moses observed that PCI is more cost-effective than CABG for left main disease despite the subsequent higher readmission rate, according to data from a SYNTAX analysis (Cohen DJ, et al. Catheter Cardiovasc Interv. 2012;79(2):198-209).

Potential Confounders

Dr. Moses called attention to some imbalances in comorbidities between the groups that may have influenced the results. For example, pulmonary readmission was 12.5% in the PCI group compared to 1.8% in the CABG group. “There’s no reason that pulmonary problems should be more prevalent in the PCI group,” he said, adding, “It’s likely due to underlying comorbidities such as lung disease.”

Also, Dr. Leva suggested that some PCI revascularizations might have been performed in asymptomatic patients due to the ‘oculo-stenotic reflex’ after follow-up angiography.

Future studies should focus on long-term evaluation of readmissions due to the natural cycle of CABG in comparison to PCI, posited Dr. Leya. Bypasses usually do not cause problems for up to 5 or 6 years, but at that point vein grafts are more likely to fail, while internal mammary arteries may fail at 10 years, he noted. 

Dr. Moses added that the EXCEL study, which just finished enrollment, will provide more definitive answers about the choice of PCI vs CABG for treatment of left main disease.

Related Stories:

• PRECOMBAT: PCI with Sirolimus Stent Equivalent to CABG in Left Main Disease
• Long-Term Outcomes Similar for CABG vs DES in Women with Left Main Disease
• Meta-analysis: Cumulative Stroke Higher with CABG vs. PCI; Late Stroke Comparable