Restenosis at Routine Angiographic Follow-up Predicts Long-term Mortality After PCI

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In patients who have undergone percutaneous coronary intervention (PCI), restenosis detected by surveillance angiography is associated with increased risk of long-term mortality, according to a study published online October 8, 2014, ahead of print in the European Heart Journal. The finding held true regardless of whether patients were symptomatic at the time of angiography. 

Compared with patients who received surveillance angiography, those who did not meet enrollment criteria were older and more likely to be diabetic but had a similar proportion of DES implanted. At time of follow-up angiography, 5.0% of patients had ACS, 43.2% had stable angina, and 51.8% were asymptomatic.

Restenosis an Independent Predictor

At 4 years, restenosis was detected in 26.4% of patients (3,098 treated lesions) with a median diameter stenosis of 68.6 ± 15.8%.  Restenosis morphology was 34% focal body, 15% focal margin, 5% multifocal, 38% diffuse, 2% proliferative, and 5% occlusive. Of patients with restenosis, 65.2% underwent TVR at the operator’s discretion, with a success rate of 98% and final diameter stenosis of 15.5 ± 12.0%.

Kaplan-Meier estimated 4-year mortality was higher in patients with restenosis (9.6%) compared with those without (8.3%; P = .03). Interestingly, in the restenosis group, mortality rates were similar regardless of whether or not patients received TVR subsequent to angiography (P = .43).

On multivariable analysis, factors independently associated with higher likelihood of mortality at 4 years were:

• Restenosis at angiography
• Age (per 10-year increase)
• Diabetes
• Current smoking
• LVEF (per 5% decrease) 

Female sex was associated with lower likelihood of death at 4 years. Additionally, when analyzed by presentation type, those with ACS received angiography sooner than other patients and had the highest 4-year-mortality risk (overall P < .001).

In the 51.8% of patients who were asymptomatic at follow-up angiography, 18.4% were found to have restenosis. Of these, 40.7% underwent TVR; restenosis was more severe in this subset. Four-year mortality rates in the asymptomatic population were higher for those with vs without restenosis (9.2% vs 7.0%; P = .02). The same factors associated with increased likelihood of death in the overall cohort were also independent predictors in the asymptomatic population.  

Role of Surveillance Angiography Beyond Study’s Scope

According to the study authors, the findings suggest that restenosis in the months after stenting provides additional clinically relevant information concerning long-term mortality risk. But importantly, the study “does not indicate that routine control angiography per se is a predictor of long-term mortality,” they add. “Indeed, the understanding of a potential role for routine angiographic surveillance for risk stratification in PCI-treated patients, as well as of a prognostic role of reintervention in patients presenting asymptomatic restenosis, is beyond the scope of this study.”

Dr. Kastrati and colleagues also note that survival curves for patients with and without restenosis appeared to diverge soon after undergoing follow-up angiography, which raises important questions.

“Higher rate of repeat revascularization is recognized to be the principal trade-off of routine control angiography, and it is important to exclude the potential adverse impact of repeat revascularization in patients presenting angiographic restenosis,” they add. However, the researchers say the finding that mortality was not impacted by the decision to perform TVR “speaks against a negative influence of repeat revascularization at the time of control angiography on subsequent mortality risk out to 4 years.”

No Clear Causal Link

But in a telephone interview with TCTMD, Sorin J. Brener, MD, of Weill Cornell Medical College (New York, NY), said that while the paper provides a good opportunity to look at mortality in a large group of patients with follow-up angiography, there is no clear evidence that restenosis was the cause of death in all patients.  

“We don’t know if the deaths were related to the restenosis itself or simply to a progression of coronary artery disease,” Dr. Brener observed. “All we can really say is that there was an association between the restenosis and the increase in mortality. It would be incorrect to interpret this as saying we should be doing surveillance angiography in everybody who has successful stenting.”

Dr. Brener added that although the study authors suggest there is no negative impact of treating the restenosis, separation of the survival curves immediately after follow-up angiography “makes you believe that some of these deaths were in fact related to the procedures that were done because restenosis was found.”

While Dr. Kastrati and colleagues advocate for a randomized trial to look at the issue further, Dr. Brener said the prospect is unlikely.

“I doubt there would be wide support for the idea because patients don’t like control angiography, especially when they are asymptomatic. Plus, it would take an enormous number of patients to do something like that,” he concluded.

Source:
Cassese S, Byrne RA, Schulz S, et al. Prognostic role of restenosis in 10,004 patients undergoing routine control angiography after coronary stenting. Eur Heart J. 2014;Epub ahead of print.

Disclosures:

• Dr. Kastrati reports submitting patents in relation to a number of DES technologies and receiving consulting or lecture fees from Abbott,Biosensors, and Biotronik.
• Dr. Brener reports no relevant conflicts of interest.

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