麻豆传媒

A risk assessment tool may identify patients who are candidates for 6-month dual antiplatelet therapy (DAPT) after percutaneous coronary intervention (PCI), according to a secondary analysis of the PRODIGY trial.

Those with a DAPT score of at least 2 had numerically but not significantly reduced odds of death, MI, and cerebrovascular accident with prolonged DAPT (4.2% for 24 months versus 6.2% for 6 months), while shortened DAPT trended better in this regard for patients with lower scores (9.8% versus 6.8%, P=N.S.)

Meanwhile, BARC 3 or 5 bleeding rates showed that safety was a concern with 24-month DAPT for low-scorers (3.7% versus 1.1% with 6-month DAPT, risk difference 2.58, 95% CI 0.71-4.46), Marco Valgimigli, MD, PhD, of Bern University Hospital in Switzerland, and colleagues reported.

A high DAPT score, on the other hand, was associated with no different risks in bleeding whether patients took 24- or 6-month DAPT (1.2% versus 1.0%, P=N.S.), according to the PRODIGY data published in the

"In conclusion, our study supports the use of the DAPT score for unselected patients undergoing PCI to identify those who are at higher risk for bleeding and concomitantly less likely to derive benefit from prolonged therapy," Valgimigli's group wrote.

"The present study provides additional evidence on use of the DAPT score in a less selective PCI population, in which randomization to DAPT duration was performed at 1 month without a priori knowledge about tolerability of a 12-month DAPT course (as was the case in the DAPT Study)."

In another departure from the DAPT Study, PRODIGY had fewer exclusion criteria, according to the trial investigators.

PRODIGY also showed that prolonged DAPT only worked for high-scorers who got paclitaxel-eluting stents (not bare metal stents, zotarolimus-, or everolimus-eluting stents).

"Prolonged therapy was effective in preventing ischemic events only among patients with a high score who received early-generation paclitaxel-eluting stents. However, prolonged DAPT was safe in patients with high scores, regardless of the type of stent received, because it was associated with a risk for bleeding similar to that of short DAPT," the authors suggested.

"Whether prolonged DAPT benefits patients with high scores treated with contemporary drug-eluting stents [DES] requires further study," they added.

"Although risk scores can assist with decision making, clinical judgment remains essential. There may be PCI patients with current-generation DES for whom DAPT duration as short as 1 month or as long as a lifetime is reasonable," agreed J. Dawn Abbott, MD, of Rhode Island Hospital in Providence.

Valgimigli's study "suggests that the DAPT score can be used to identify patients who should be treated with short term DAPT, but it is not useful for determining which patients treated with current-generation drug-eluting stents derive a net benefit from extending therapy beyond 1 year," she commented in an accompanying editorial.

Abbott brought up other risk assessment tools like the PARIS score and the PRECISE-DAPT score, which have yet to be compared against each other or the DAPT score.

"Although current DAPT scores include clinical and in some cases procedural variables, there are genetic determinates of responsiveness to antiplatelet therapy and risk for spontaneous coronary events," she suggested.

Furthermore, she wrote, "the future may bring point-of-care genetic tests or imaging methods that better identify patients who are vulnerable to recurrent ischemic events. Patient preferences also matter. We should strive to practice shared decision making that factors in evidence and patient values."

The PRODIGY analysis included 1,970 patients who were randomized at 30 days post-PCI to 6 or 24 months DAPT. Of these participants, 884 had a retrospectively-calculated DAPT score of 2 or higher.

High-scorers were younger, more likely to be men, and presented with acute MI in greater numbers.

That the DAPT score wasn't available prospectively was a limitation to the study, as was the low ischemic event rate.