Relationship between intravascular ultrasound guidance and clinical outcomes after drug-eluting stents: the ADAPT-DES study

Selected in Circulation by F. D'Ascenzi

References

Authors

Bernhard Witzenbichler; Akiko Maehara; Giora Weisz; Franz-Josef Neumann; Michael J. Rinaldi; D. Christopher Metzger; Timothy D. Henry; David A. Cox; Peter L. Duffy; Bruce R. Brodie; Thomas D. Stuckey; Ernest L. Mazzaferri Jr.; Ke Xu; Helen Parise; Roxana Mehran; Gary S. Mintz; Gregg W. Stone

Reference

CIRCULATIONAHA.113.003942

Published

November 2013

Link

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My Comment

Background

Witzenbichler and colleagues provide new evidence of a pre-specified substudy of the ADAPT-DES (Assessment of Dual Antiplatelet Therapy with Drug-Eluting Stents; a large-scale, prospective, multicenter study) registry, comparing clinical outcomes between IVUS-guided and angiography-guided PCI. The final population consisted of 8583 patients: IVUS-guided stenting was performed in 3349 patients (39%) while angiography-guided stenting was performed in 5234 patients (61%).

Major findings

The unadjusted 1-year rate of definite/probable stent thrombosis (0.6% vs. 1.0%, HR 0.53, 95% CI 0.31-0.90, p=.017) and the unadjusted 1-year rate of MI (2.5% vs. 3.7%, HR 0.67, 95% CI 0.51-0.87) were significantly lower in IVUS-guided group compared to the angiography-guided group;

  • IVUS-guided procedures were associated with lower rates of target vessel MI (1.7% vs. 2.9%, p=.004) as compared with the angiography-guided group. The type of MI which was most reduced with IVUS guidance was spontaneous MI (0.8% vs. 1.5%, HR 0.53, 95% CI 0.34-0.82, p=.004).
  • The overall 1-year rate of adjudicated MACE (defined as cardiac death, definitive/probable stent thrombosis, or MI) was significantly less in the IVUS-guided group compared to the angiography-guided group (3.1% vs. 4.7%, HR 0.67, 95% CI 0.53-0.84, p=.0006);
  • Propensity-adjusted multivariate analysis demonstrated that IVUS guidance was associated with reduced rates of definitive/probable stent thrombosis (adjusted HR 0.40, 95% CI 0.21-0.73, p=.003), myocardial infarction (adjusted HR 0.66, 95% CI 0.49-0.88, p=.004), and MACE (adjusted HR 0.70, 95% CI 0.55-0.88, p=.003) at one year with the greatest benefit emerging among patients with acute coronary syndromes and complex lesions. However, significantly better event-free survival was observed in all patient groups.

My comments

While IVUS guidance was reported to reduce the risk of restenosis and repeat revascularisation in the bare metal stent era, the use of IVUS after DES implantation failed to improve clinical efficacy with IVUS guidance. Witzenbichler and colleagues reported new relevant data from a large prospective study with an all-comers patient population. They demonstrated, in the largest prospective IVUS study performed to date, that IVUS guidance PCI has a relevant clinical impact also in DES era. Furthermore, even if benefits in terms of event-free survival was observed in all patient groups, the authors demonstrated that particularly patients with complex target lesions and with acute coronary syndrome presentation can greatly benefit from a IVUS-guided PCI.

Even if the investigators used propensity-adjusted multivariable analyses in an attempt to minimize the risk of bias, as suggested by Räber and Windecker in their editorial, important differences in patient and lesion characteristics exist in this study. IVUS patients were younger, had less previous CABG and three-vessel disease, had a higher left ventricular ejection fraction, had a more extended duration of dual anti-platelet therapy and received new generation DES more frequently. Thus, IVUS assignment was not free from bias and, despite using propensity-adjusted multivariable analyses, residual confounding factors cannot be excluded beyond reasonable doubt. Furthermore, other predictors than IVUS guidance seem to predict the clinical events (e.g. premature DAPT discontinuation, diabetes mellitus, renal insufficiency, acute coronary syndrome presentation…), supporting the concept that IVUS-guided optimization of the procedure is one of the fundamental step needed to reduce the rates of MACE after PCI.

Further studies are needed to assess the benefit and to identify specific criteria to optimize the procedure using IVUS, particularly in the new setting of ACS patients treated with novel P2Y12 inhibitors.

References

Räber L, Windecker S. IVUS-guided percutaneous coronary interventions: an ongoing Odyssey? Circulation 2013

1 comment

  • amedeo Ferro 29 Jul 2014

    Most of stent thrombosis are due either to inadequate stent expasion or to undersized stent, so no wonder that IVUS halved stent thrombosis.The questions is why is IVUS so underutilized outside from Japan an S. Korea?