Reduced CV risk, no increased bleeding with extended-term DAPT post-PCI

Dual antiplatelet therapy (DAPT) for >12 months should remain the standard of care (SoC) for high-risk patients with acute coronary syndrome (ACS) who have undergone percutaneous coronary intervention (PCI), suggested a study presented at SCAI 2021.

“[L]ong-term DAPT (>12 months) was associated with a lower risk for major cardiovascular composite endpoints without any measurable increase in clinically relevant bleeding events compared with shorter DAPT duration [of ≤12] months,” presented Dr Hao-Yu Wang from the Fuwai Hospital, National Center for Cardiovascular Diseases, Chinese Academy of Medical Sciences & Peking Union Medical College, Beijing, China.

Using the prospective Fuwai PCI Registry, Wang and co-authors identified consecutive high-risk patients who underwent PCI and fulfilled the “TWILIGHT-like” criteria. To qualify, these patients needed to have ACS and at least one clinical and one angiographic feature indictive of high risk of bleeding or ischaemic events as per inclusion criteria in the TWILIGHT trial, and be event free 12 months following PCI (n=4,875, _^~77 percent male). Of these, 3,335 and 1,540 individuals received extended-term and short-term DAPT, respectively.

Compared with patients on short-term DAPT, those on extended-term DAPT had a 63 percent lower risk of the composite outcome of all-cause death, myocardial infarction (MI), or stroke at 30 months (1.5 percent vs 3.8 percent; adjusted hazard ratio [adjHR], 0.374, 95 percent confidence interval [CI], 0.256–0.548; p<0.001; HR_matched [propensity-score matched], 0.361, 95 percent CI, 0.221–0.590; p<0.001). [SCAI 2021, abstract FCR-04]

Extended-term DAPT also reduced the risks for cardiovascular death compared with short-term DAPT in both the multivariable (adjHR, 0.066, 95 percent CI, 0.019–0.223; p<0.001) and propensity-score matched analysis (HR_matched, 0.049, 95 percent CI, 0.007–0.362; p=0.003).

The risk for definite or probable stent thrombosis was also reduced with extended-term vs short-term DAPT, though only in the multivariable analysis (adjHR, 0.374, 95 percent CI, 0.143–0.977; p=0.045).

Additionally, the risk for all-cause mortality was significantly reduced among patients on extended-term vs short-term DAPT in both the multivariable (adjHR, 0.069, 95 percent CI, 0.029–0.165) and propensity-score matched analysis (HR_matched, 0.051, 95 percent CI, 0.012–0.211; p<0.001 for both).

“[The] significant reduction in all-cause mortality among patients receiving extended-term DAPT [was] driven mostly by a reduction in cardiovascular death, [though this] requires a cautious interpretation in view of the similar rates of MI and stroke [p=0.214 and p=0.289, respectively, in the multivariable analysis and p=0.146 and p=0.461, respectively, in the propensity-score matched analysis],” Wang pointed out.

The rates of BARC** type 2, 3, or 5 bleeding did not differ between patients who received extended-term and short-term DAPT (0.9 percent vs 1.3 percent; adjHR, 0.668, 95 percent CI, 0.379–1.178; p=0.164; HR_matched, 0.721, 95 percent CI, 0.369–1.410; p=0.339).

The results were consistent regardless of the number of risk factors in patients (1–3, 4–5, or 6–9).

The current guidelines for ACS treatment “include more aggressive risk factor modification and prolonged antiplatelet therapy and recommend DAPT for a minimum of 12 months following an ACS, regardless of whether or not PCI is performed,” said Wang.

However, studies have produced contrasting results on the efficacy and safety of a shorter treatment strategy in patients who have undergone PCI, he said. 

“Recent emphasis on reduced duration and/or intensity of antiplatelet therapy following PCI irrespective of indication for PCI may fail to account for the substantial risk of subsequent nontarget lesion events in ACS patients,” he continued.

“[The present] results suggest that prolonged DAPT in ACS patients who present with a particularly higher risk for thrombotic complications without excessive risk of bleeding could remain the SoC,” he concluded.