Coronary Bifurcations: Application of the Crushing Technique Using Sirolimus-Eluting Stents - CACTUS

Description:

The goal of the trial was to evaluate the routine use of the "crush" technique compared with provisional side-branch T-stenting for the treatment of coronary bifurcations.

Hypothesis:

The "crush" technique would be more effective in preventing restenosis and major adverse cardiac events (MACE).

Study Design

  • Randomized
  • Parallel

Patients Enrolled: 350
Mean Follow Up: 6 months
Mean Patient Age: 65 years
Female: 20%
Mean Ejection Fraction: 55%

Patient Populations:

  • Patients at least 18 years of age with stable angina, unstable angina, or a positive stress test
  • Coronary bifurcation lesion with a reference vessel diameter of 2.5-3.5 mm for the main branch and 2.25-3.5 mm for the side branch

Exclusions:

  • Pregnancy
  • MI in the past 24 hours or TIMI flow 0 in either branch
  • Lesion length >28 mm in either branch
  • Left main trunk lesion unprotected by a bypass graft
  • Visible thrombus within the lesion
  • Chronic total occlusion
  • Left ventricular ejection fraction <35%
  • Renal insufficiency
  • Contraindication to one of the study drugs

Primary Endpoints:

  • In-segment restenosis at 6 months
  • MACE defined as cardiovascular death, MI, or target vessel revascularization at 6 and 12 months; only 6-month outcomes reported here

Secondary Endpoints:

  • In-stent late lumen loss
  • Q-wave or non-Q-wave MI
  • Stent thrombosis

Drug/Procedures Used:

After diagnostic coronary angiography was performed, patients with a bifurcation lesion were randomized to a strategy of double stenting using the "crush" technique (n = 177) versus main-branch stenting with provisional T-stenting of the side branch (n = 173).

In the double stent group, predilation and final kissing balloon inflation of both branches were mandatory. In the provisional stent group, final kissing balloon inflation was also mandatory. The side branch was provisionally stented by the "T" technique if there was more than a 50% residual stenosis or there was a flow-limiting dissection. Sirolimus-eluting stents were used for both groups.

Concomitant Medications:

All patients were pretreated with aspirin and a thienopyridine. Unfractionated heparin was used to achieve an activated clotting time of 250-300 seconds. A glycoprotein IIb/IIIa inhibitor could be used according to operator discretion. After the procedure, aspirin was recommended for life, and the thienopyridine was administered for at least 6 months.

Principal Findings:

Overall, 350 patients were randomized. With the exception of hypertension, baseline demographics and angiographic characteristics were well matched. In the double stent group, the mean age was 65 years, 20% of participants were women, 71% of participants had hypertension (80% in the provisional stent group, p = 0.05), and left ventricular ejection fraction was 55%. The location of the bifurcation lesion was left anterior descending/diagonal in 74%, circumflex/obtuse marginal in 19%, and right coronary artery/posterior descending artery in 7%. Glycoprotein IIb/IIIa inhibitors were used in 23% of the double stent group and 17% of the provisional stent group.

Angiographic success was obtained in 98.9% of the double stent group and 97.7% of the provisional stent group. In the provisional stent group, the side branch was stented in 31% of patients. This was most commonly done for residual stenosis of the side branch (in 72% of cases). Final kissing balloon inflation was not performed in 7.9% of the double stent group versus 9.8% of the provisional stent group. In approximately half of the cases, this was not performed due to inability to re-cross with the wire or balloon. In the remaining cases, the operator elected not to perform this step.

At 6 months, MACE (cardiovascular death, myocardial infarction [MI], or target vessel revascularization) occurred in 15.8% of the double stent group versus 15.0% of the provisional stent group (p = 0.95). For individual outcomes, noncardiac death occurred in 0% versus 0%, MI occurred in 0.5% versus 0.5%, and target vessel revascularization occurred in 7.9% versus 7.5%, respectively, for the double stent group versus provisional stent group. Stent thrombosis to 6 months occurred in 1.7% versus 1.1%, respectively. For both groups, final kissing balloon inflation reduced the incidence of target lesion revascularization and stent thrombosis.

Angiographic follow-up was performed in 86% of patients. At 6 months, in-segment restenosis of the main branch occurred in 4.6% versus 6.7%, while in-segment restenosis of the side branch occurred in 13.2% versus 14.7%, respectively, for the double stent group versus provisional stent group. For both groups, final kissing balloon inflation reduced the incidence of MI.

Interpretation:

Among patients with a true bifurcation lesion, a more complex strategy of double stenting with the "crush" technique is not superior to only stenting the main branch with provisional stenting of the side branch. A second stent was required in 31% of cases in the provisional stent group; however, this was mostly required for residual stenosis of at least 50%. The incidence of MACE and in-segment restenosis at 6 months was similar between the two groups. Stent thrombosis was also similar between the groups. For both groups, final kissing balloon inflation appeared to reduce the incidence of restenosis and MACE.

Coronary bifurcations remain a difficult lesion subset to treat. The CACTUS trial now complements several other trials that also failed to show the superiority of a strategy of complex double-vessel stenting. While main-branch stenting with provisional side-branch stenting appears to be the first-line treatment for most bifurcation lesions, double-vessel stenting might be selected, according to individual lesion and anatomical characteristics.

References:

Colombo A, Bramucci E, Saccà S, et al. Randomized Study of the Crush Technique Versus Provisional Side-Branch Stenting in True Coronary Bifurcations. The CACTUS (Coronary Bifurcations: Application of the Crushing Technique Using Sirolimus-Eluting Stents) Study. Circulation 2009;119:71-8.

Clinical Topics: Invasive Cardiovascular Angiography and Intervention, Noninvasive Imaging, Prevention, Stable Ischemic Heart Disease, Interventions and Imaging, Angiography, Nuclear Imaging, Hypertension, Chronic Angina

Keywords: Myocardial Infarction, Angina, Stable, Coronary Angiography, Thrombosis, Drug-Eluting Stents, Stroke Volume, Constriction, Pathologic, Coronary Vessels, Sirolimus, Hypertension, Exercise Test


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