Side Branch is the Main Determinant Factor of Bifurcation Lesion Complexity: Critical Review with a Proposal Based on Single-centre Experience

Comparison of angiographic change in side-branch ostium after drug-coated balloon vs. drug-eluting stent vs. medication for the treatment of de novo coronary bifurcation lesions

OBJECTIVES

Data on side-branch (SB) ostial effect after drug-coated balloon (DCB) treatment in the context of de novo coronary bifurcation lesions are limited. We aimed to investigate the angiographic outcomes of SB ostium after DCB treatment compared with drug-eluting stents (DESs) implantation in the main vessel (MV) or optimal medical therapy (OMT) for the treatment of de novo coronary bifurcation lesions.

METHODS

Serial angiographic changes in the SB ostium were compared between DCB, DES, and medication alone for MV treatment. Δ value was calculated by subtracting the follow-up value from the pre-procedure value.

RESULTS

A total of 132 bifurcation lesions were included for analysis (44 lesions in DCB group; 38 lesions in DES group; 50 lesions in OMT group). The minimal lumen diameter (MLD) of SB ostium showed an increase at follow-up in the DCB group, whereas a decrease was observed in both the DES and OMT groups (ΔMLD: -0.16 ± 0.45 mm for DCB group vs. 0.50 ± 0.52 mm for DES group vs. 0.08 ± 0.38 mm for OMT group, p < 0.001). The diameter stenosis (DS) of SB ostium showed a marked decrease at follow-up in the DCB group, in contrast to an increase observed in both the DES and OMT groups (ΔDS: 8.01 ± 18.96% for DCB group vs. -18.68 ± 18.60% for DES group vs. -2.05 ± 14.58% for OMT group, p < 0.001).

CONCLUSIONS

In de novo coronary bifurcation lesions, DCB treatment on the MV demonstrated favorable angiographic outcomes in the SB ostium at 6-9 month follow-up compared to DES implantation or OMT.

Standardized angiographic projections allow evaluation of coronary artery side branches with quantitative flow ratio (QFR)

Quantitative flow ratio (QFR) is a novel, software-based noninvasive method for the quantitative evaluation of coronary physiology. QFR results correlate with invasive FFR measurements in the three main epicardial coronary arteries. However, QFR data for the evaluation of coronary side branches (SB) are scarce. The evaluation of QFR-performance of SB was retrospective and prospective. Eighty-seven patients with suspected chronic coronary syndrome, who received angiography using routine core lab projections, were retrospectively analyzed. On the second part 37 patients, who received angiography using recommended standardized coronary angiography projections, were prospectively analyzed. Quantitative analysis was performed for SB with a maximum lumen diameter proximal of ≥2 mm based on quantitative coronary angiography (QCA) by two certified experts with the software QAngio XA 3D 3.2. Using routine projections, QFR computation in 55 % of the SB were obtained (123 out of 224). Using standardized projections, 85 % of SB were computed by QFR (64 out of 75; p < 0.001 vs routine projections). The fluoroscopy time for recommended projections was not significantly different as opposed to routine projections (3.75 ± 2.2 vs. 4.58 ± 3.00 min, p = 2.6986). Using the standardized projections was associated with a higher amount of contrast medium (53.44 ± 24.23 vs. 87.95 ± 43.73 ml, p < 0.01), longer overall procedure time (23.23 ± 16.35 vs. 36.14 ± 17.21 min, p < 0.01) and a higher dose area product (1152.28 ± 576.70 vs. 2540.68 ± 1774.07 cGycm2, p < 0.01). Our study shows that the blood flow of the vast majority of coronary SB can be determined non-invasively by QFR in addition to the main epicardial coronary arteries when standardized projections are used.

Outcomes of Provisional Stenting With Versus Without Side Branch Intervention in Patients With Bifurcation Lesion-Related ST-Segment Elevation Myocardial Infarction

To date, the best approach to coronary bifurcation lesion remains unsettled, and the parameters to guide side branch ballooning or stenting are not yet defined. This study aimed to compare the survival outcomes after provisional stenting with versus without side branch intervention. A cohort was conducted on 132 patients who underwent coronary angiography at Toulouse University Hospital for ST-segment elevation myocardial infarction with large culprit nonleft main coronary bifurcation lesion. Study participants were divided into 2 groups depending on the performance or not of a side branch intervention. We observed the living status at 1-year after hospital discharge. Side branch intervention by balloon inflation or final balloon kissing technique was performed in 34.1% of study participants. At 1-year follow-up, the incidence of all-cause mortality was 7.8 per 100 person-years (95% confidence interval [CI] 4.1 to 15), and although it seemed higher in the side branch intervention group (10 per 100 person-years [95% CI 3.8 to 26.7] vs 6.6 per 100 persons-years [95% CI 2.8 to 15.9]), the survival analyses showed no differences in survival outcomes (hazard ratio side branch intervention 1.55 [0.42 to 5.78], p = 0.513). In conclusion, in the setting of a coronary bifurcation causing ST-segment elevation myocardial infarction, simple provisional stenting without side branch intervention showed a low mortality rate and no differences in the 1-year survival outcomes.