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New standardized score uncovers patients who could benefit from shorter duration DAPT

Patients who have undergone percutaneous coronary intervention and are at risk for harm by prolonged dual-antiplatelet therapy, or DAPT, can be identified via a new DAPT standardized score and can be managed with a short DAPT regimen without an increased risk for ischemic events, according to recent data.

In patients with coronary artery disease undergoing percutaneous coronary intervention (PCI), the evidence-based, guideline-recommended standard of care is to initiate DAPT following the procedure, Raffaele Piccolo, MD, from Bern University Hospital in Switzerland, and colleagues wrote in Annals of Internal Medicine. A minimum of 1 to 6 months of DAPT is recommended after PCI depending on clinical presentation and stent type yet, because the protective benefits of DAPT are offset by an increase in bleeding complications, the optimal duration of treatment is uncertain, they added.

“The DAPT score is a new standardized tool to identify patients who would derive benefit or harm from prolonged DAPT,” but has not been evaluated outside the derivation cohort included in the DAPT Study, they wrote.

To address this, Piccolo and colleagues retrospectively assessed the safety and efficacy of DAPT duration as guided by the score in a randomized clinical trial of 1,970 patients who were undergoing PCI from the Prolonging Dual-Antiplatelet Treatment After Grading Stent-Induced Intimal Hyperplasia study. Patients were randomly assigned to DAPT (aspirin and clopidogrel) after PCI for either 24 months (prolonged) or six months or less (short).

Data indicated 44.9% (n = 884) of patients had a DAPT score of 2 or greater and 55.1% (n = 1,086) had a score less than 2.

Greater reductions in primary efficacy outcomes, including death, myocardial infarction or cerebrovascular accident, were observed in patients with high scores who were treated with 24 months of DAPT compared with 6 months (risk difference [RD] for score 2, –2.05 percentage points [95% CI, –5.04 to 0.95 percentage points]; RD for score < 2, 2.91 percentage points [95% CI, –0.43 to 6.25 percentage points]; P = 0.030). However, the performance of the DAPT score varied based on stent type. Prolonged DAPT prevented ischemic events only in patients with high scores who received early-generation paclitaxel-eluting stents (RD, –7.55 percentage points [95% CI, –12.85 to –2.25 percentage points]).

Patients with low scores had greater increases in the primary safety outcome of Bleeding Academic Research Consortium type 3 or 5 bleeding with prolonged DAPT compared with short treatment (RD for score 2, 0.2 percentage point [95% CI, –1.20 to 1.60 percentage points]; RD for score < 2, 2.58 percentage points [95% CI, 0.71 to 4.46 percentage points]; P = 0.046). In patients with a high DAPT score, prolonged treatment was safe regardless of stent type used.

“[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,” Piccolo and colleagues concluded. “The DAPT score correctly identified patients deriving benefit and no harm from prolonged therapy when patients receiving a paclitaxel-eluting stent were evaluated, but not when they were excluded in a sensitivity analysis. Further validation of the DAPT score is therefore needed in a large contemporary cohort of patients treated with newer-generation drug-eluting stents.”

In a related editorial, J. Dawn Abbott, MD, from Warren Alpert School of Medicine at Brown University and Rhode Island Hospital, wrote that although the findings by Piccolo and colleagues indicate clinicians can use the DAPT score to identify who should be treated with short-term DAPT, it does not aid in establishing which patients who are treated with current-generation drug-eluting stents obtain a net benefit from extending therapy beyond 1 year.

“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 concluded. “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.” – by Alaina Tedesco

Disclosures: Piccolo reports receiving a research grant from the Veronesi Foundation. Abbott reports grants from AstraZeneca, Medinol, Bristol-Myers Squibb and Abbott Cardiovascular Systems, as well as other support from Recor and Pfizer. Please see full study for complete list of all other authors’ relevant financial disclosures.