A Prospective Randomized Trial of Side Branch Dilatation Strategies in Patients With Coronary Bifurcation Lesions Undergoing Treatment With a Single Stent - Nordic-Baltic Bifurcation Study III

Description:

In the case of coronary bifurcation lesions, stenting of the main artery with optional stenting of the side branch (SB) is the preferred strategy. However, in certain situations, a simple one-stent technique can be employed. In these situations, it is unknown if simultaneous kissing balloon inflation of the main vessel (MV) and the SB post-stenting is associated with better outcomes.

Hypothesis:

Kissing balloon dilatation post-stenting of the main artery would be associated with better outcomes, as compared with no kissing balloon dilatation in patients with bifurcation lesions.

Study Design

  • Randomized
  • Stratified

Patients Enrolled: 477
Mean Follow Up: 6 months
Mean Patient Age: 64.5 years
Female: 27%
Mean Ejection Fraction: 58.5%

Patient Populations:

  • PCI for any indication
  • Lesion location: LAD/diagonal, circumflex (CX)/obtuse marginal, right coronary artery/posterior descending artery/posterolateral branch, left main/LAD/CX
  • Vessel size: main vessel diameter ≥2.5 mm, side branch diameter ≥2.25 mm

Exclusions:

  • ST-elevation acute MI within 24 hours
  • Expected survival <1 year 
  • S-creatinine >200 µmol/L
  • Allergy to aspirin, clopidogrel, or ticlopidine
  • Allergy to sirolimus

Primary Endpoints:

  • MACE at 6 months (cardiovascular death, target vessel MI, TLR, stent thrombosis)

Secondary Endpoints:

  • Individual components of primary outcome
  • Periprocedural MI
  • Canadian Cardiovascular Society angina class at 6 months
  • Procedural endpoints

Drug/Procedures Used:

Both the MV and SB were wired, with predilatation at the discretion of the operator. Sirolimus stents were used for stenting the MV, with jailing of the SB wire. At this point, if TIMI 3 flow was present in the SB, patients were randomized to either final kissing balloon dilatations, or no further intervention, irrespective of the presence of a severe ostial lesion in the SB. In the final kissing balloon arm, the SB was rewired through the MV stent, and simultaneous kissing balloon dilatation was performed.

Concomitant Medications:

Glycoprotein IIb/IIIa inhibitors (29.0%), bivalirudin (24%), clopidogrel (99%), and aspirin (99.8%)

Principal Findings:

A total of 477 patients were enrolled, 238 to kissing balloon, and 239 to no kissing balloon. Baseline characteristics were fairly similar between the two groups. About 17% of patients were diabetic, and 27% had a history of prior percutaneous coronary intervention (PCI). The majority of patients underwent PCI for stable angina (74%). The most common treated vessel was the left anterior descending (LAD) (73%); left main stenting was done in about 7.5% of the patients. Multivessel disease was noted in about 52% of the patients. The mean MV lesion length was 17.5 mm, and the mean SB lesion length was 3.5 mm. The mean reference vessel diameter in the MV was 3.4 mm, and in the SB was 2.7 mm. SB stenting was necessary in <1% of the total population. The target lesion was in the LAD in about 70% of the patients. True bifurcation lesions (Medina class 1,1,1; 1,0,1; and 0,1,1) constituted about 50% of all lesions.

Procedure time (61 vs. 47 minutes, p = 0.0001), fluoroscopic time (16 vs. 11 minutes, p = 0.0001), and contrast use (235 vs. 200 ml, p = 0.0001) were significantly higher in the kissing balloon arm compared with the no kissing balloon arm. There was no difference in the incidence of major adverse cardiac events (MACE) at 6 months between the two arms (2.1% vs. 2.5%, p = 1.0). Other outcomes, such as stent thrombosis (0.4% in both arms, p > 0.05), target lesion revascularization (TLR) (1.3% vs. 2.1%, p > 0.05), and overall mortality (1.2% vs. 0%, p > 0.05) were similar between the two arms. The incidence of periprocedural myocardial infarction (MI) was also similar between the two arms (6.3% in both arms, p > 0.05). Findings were similar for patients with true bifurcation lesions as well. At 8-month angiographic follow-up, in-stent restenosis of ≥50% was lower in the final kissing balloon arm (7.9% vs. 15.4%, p = 0.039).

Interpretation:

The results of this trial indicate that a strategy of routine SB kissing balloon dilatation through the MV stent is not associated with better outcomes at 6 months, as compared with no kissing balloon dilatation, with an increase in procedure and fluoroscopic times, and the total amount of contrast use. The use of kissing balloon dilatation of the SB through the main stent should be reserved to situations such as poor flow into the SB, or significant ostial stenosis due to plaque shifting with clinical, hemodynamic, or electrocardiographic changes.

References:

Niemelä M, Kervinen K, Erglis A, et al., on behalf of the Nordic-Baltic PCI Study Group. Randomized Comparison of Final Kissing Balloon Dilatation Versus No Final Kissing Balloon Dilatation in Patients With Coronary Bifurcation Lesions Treated With Main Vessel Stenting: The Nordic-Baltic Bifurcation Study III. Circulation 2011;123:79-86.

Presented by Dr. Matti Niemela at the Transcatheter Cardiovascular Therapeutics meeting (TCT 2009), San Francisco, CA, September 25, 2009.

Clinical Topics: Invasive Cardiovascular Angiography and Intervention, Stable Ischemic Heart Disease, Atherosclerotic Disease (CAD/PAD), Interventions and Coronary Artery Disease, Chronic Angina

Keywords: Myocardial Infarction, Coronary Artery Disease, Follow-Up Studies, Angina, Stable, Human Rights, Dilatation, Sirolimus, Constriction, Pathologic, Hemodynamics, Percutaneous Coronary Intervention, Stents, Thrombosis, Diabetes Mellitus


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