Dec. 5 – The use of an intravascular ultrasound (IVUS) -guided percutaneous coronary intervention (PCI) with drug-eluting stents (DES) yields clinical benefit in terms of stent thrombosis (ST) and major adverse cardiac events, regardless of DES type, according to a study that took place at the Washington Hospital Center (WHC) in Washington, D.C.
Probal Roy, MD, and colleagues from the division of cardiology at WHC, examined 4,082 unselected DES patients at WHC between April 2003 and May 2006. Both Boston Scientific’s Taxus stent and Johnson & Johnson’s subsidiary Cordis’ Cypher stent were used. Out of the 4,083 patients, 2,801 patients received an IVUS-guided DES implantation in all lesions, and 1,281 patients received an angiographic-guided DES implantation.
The patient propensity-score matching was conducted to match clinical and angiographic characteristics of the two groups (IVUS and non-IVUS), taking 884 patients from each group. The characteristics included age, gender, cardiovascular risk factors, clinical presentation, left ventricular ejection fraction and angiographic features.
The in-hospital, 30-day, and one-year clinical follow-up were compared between the IVUS and the non-IVUS groups. Also, dual anti-platelet therapy was recommended to all study patients for a minimum duration of 12 months. The researchers said that the study was conducted under the local Institutional Review Board approval.
IVUS was performed either pre-intervention, post-intervention or both at the discretion of the operator. The IVUS systems that were used were Boston Scientific/Scimed’s Atlantis and Volcano Therapeutics’ Eagle Eye. The response to the IVUS findings was at the discretion of the treating physician.
For in-hospital outcomes after PCI, 11 patients in the IVUS group died, five of which were cardiac deaths, compared 20 deaths in the non-IVUS group, 11 of which were cardiac deaths. There was one incident of a Q-wave myocardial infarction in the IVUS group, compared to eight incidents in the non-IVUS group. Four patients in the IVUS group also had to receive coronary bypass surgery, compared to seven patients in the non-IVUS group.
For important outcomes in first 30 days after PCI, the cumulative ST in the IVUS group occurred in four patients (0.5 percent), and in 12 patients (1.4 percent) in the non-IVUS group. For one-year outcomes, the target lesion revascularization in the IVUS group was 43 patients (5.1 percent), compared to 61 patients (7.2 percent) in the non-IVUS group. Definite ST occurred in six patients (0.7 percent) in the IVUS group, and 18 patients (2 percent) in the non-IVUS group. Finally, 35 patients (4 percent) of the IVUS group experienced probable stent thrombosis, compared to 51 patients (5.8 percent) in the non-IVUS group.
The researchers concluded that the non-IVUS group was a predictor of cumulative ST at 12 months independent of DES type.
The limitations of the study were: it was a non-randomized, single-center, observational study; selection bias in the IVUS group was overcome by propensity-score matching; operator dependence was overcome by the large number of operators performing the study procedures; and the follow-up was restricted to 12 months.