SOLACI | Latin American Society of Interventional Cardiology

Courtesy of Dr. Alejandro Lakowsky, MTSAC.

The Journal of the American College of Cardiology (JACC) has recently published a study on the role of coronary anatomy and PCI technical difficulty in the cost benefit ratio of prolonged vs. short post procedural DAPT. This study was carried out by Robert Yeh, Laura Mauri and the DAPT trial researchers.

The study took into account not only procedural complexity (angiographically assessed), but also DAPT patient score (clinically assessed). Most of these PCI procedures were elective (54%), and a lower number were ACS driven (46%).

Complex PCIs (prespecified by the DAPT trial as: unprotected left main, >2 lesions/vessel, length ≥30 mm, bifurcation with side branch ≥2.5 mm, vein bypass graft, or thrombus-containing lesion) had higher AMI or stent thrombosis risk within the first 12 months, compared to non-complex PCI (3.9% vs 2.4%, p<0.001), but not within months 12 and 30 (3.5% vs 2.9%, p= 0.07).

Prolonged DAPT at 30 months with thienopyridines, compared to the 12 month treatment, had the same impact, further reducing AMI or stent thrombosis rate in complex PCI than in non-complex PCI, with and HR of 0.55 and 0.52, respectively.

High DAPT score (≥2) was associated with greater benefit, with prolonged DAPT, compared to subjects with low DAPT score (<2), both in complex and non-complex PCI. It is worth noticing that in patients with complex PCI and high DAPT score, long term DAPT was not associated with higher risk of moderate or severe GUSTO bleeding risk.

That might be the reason behind the subtitle to Antonio Colombo’s editorial: “Patient Complexity Is More Important than Lesion Complexity” (“La complejidad del paciente es más importante que la complejidad de la lesión”).

His conclusions slightly contradict Gennaro Giustino’s (who works for the same center in Milan) published last year, who used a slightly different form to define what complex PCI is: 3 vessels treated, ≥3 stents implanted, ≥3 lesions treated, bifurcation with 2 stents implanted, total stent length >60 mm, or chronic total occlusion.

Of nearly 10,000 patients from 6 randomized trials, 17% complied with the complex PCI criteria. In this study, the extended DAPT regime of 12 months or more, compared to a 3 to 6 DAPT, was associated to an important benefit in thrombotic event reduction in complex PCI (adjusted HR 0.56), but not in non-complex PCI (adjusted HR 1.01), while with extended treatment, bleeding risk increased similarly in both groups (HR 1.81 y 1.75, respectively).

To sum up, one article claims that prolonged DAPT reduces thrombotic events both in complex and non-complex PCI while the second finds this benefit only in complex procedures. Why the difference?

The number of elective PCIs and emergency ACS driven PCIs similar in both studies (54% and 56%), but it might have been a mistake to compare different clinical contexts, different in evolution and prognosis, and it would have been better to analyze these populations separately.

Treatment durations were different: in Yeh’s study, two long term strategies were compared (12 months vs. 30 months) in a relatively low risk population (bear in mind that randomized patients in the DAPT trial had not suffered events during the first year), while Giustino’s study compared shorter schemes (3-6 month vs. 12 month DAPT).

On the other hand, “complex PCI” definitions were different and depending on those definitions clinical evolutions could vary between a “complex” and a non-complex case, as well as their response to treatment. As mentioned before, in Giustino’s study, 17% of PCIs were the complex type, while in Yeh’s only 45% were complex.

Procedural complexity might be a predictor of ischemic complications during the first months, but beyond 12 months, clinical characteristics assessed, among others, by DAPT score, would be a better predictor than angiographies, and therefore they should guide the antithrombotic strategy.

In patients with elective non-complex PCI, with modern stents and low DAPT score, it is reasonable to adopt a shorter 3 to 6 DAPT; in patients with complex lesions, continue with 6 to 12 months; in patients with high DAPT score, especially in an ACS context, with no increased bleeding risk, maintain DAPT beyond 12 months, regardless complexity.

Courtesy of Dr. Alejandro Lakowsky, MTSAC.

Original title: Lesion Complexity and Outcomes of Extended Dual Antiplatelet Therapy After Percutaneous Coronary Intervention.

Reference: Robert W. Yeh et al. J Am Coll Cardiol 2017;70:2213–23.