There are limited data on the use of the mini-crush technique in 2-stent bifurcation percutaneous coronary intervention (PCI). Observational, multicenter (n = 7), international cohort study between 2013 and 2025, as part of the Prospective Global Registry of Percutaneous Coronary Intervention in Bifurcation Lesions (PROGRESS-BIFURCATION, NCT05100992). We evaluated procedural characteristics of patients who underwent bifurcation stenting using the mini-crush in comparison to the double kissing (DK) crush techniques. Among 2,508 bifurcation PCIs (2,284 patients), 184 (7.3%) underwent mini-crush and 257 (10.2%) DK-crush. Patients undergoing DK-crush were more likely to undergo intravascular imaging (41.9% vs 21.3%, p < 0.001). There was no difference in technical (98.4% vs 98.8%, p = 0.70) and procedural success (94.2% vs 94.9%, p = 0.77), as well as in-hospital MACE (5.0% vs 4.5%, p = 0.84). Mini-crush was associated with shorter procedural (90 [58–127] vs 107 [73–172.5] min) and fluoroscopy (24 [15.5–34.1] vs 30 [21.6–44] min) times. During a median follow-up of 754 days, as compared to DK-crush, there was a trend towards higher risk for MACE (29.8% vs 20.9%; p = 0.09) with mini-crush. Adjusted analyses with propensity score matching (aHR 1.73; 95% CI: 0.81–3.71; p = 0.14) showed no difference in MACE. In patients undergoing PCI for bifurcation lesions, the mini-crush technique had similar rates of technical and procedural success and in-hospital MACE as DK-crush and was associated with lower fluoroscopy time and procedural time. While no statistically significant differences were observed during follow-up, there was a numerical trend towards higher risk for adverse events with mini crush, and thus larger, prospective, controlled trials are needed.
Provisional stenting is the preferred technique for most bifurcation percutaneous coronary interventions (PCI). An upfront 2-stent approach, however, may be preferred in patients with complex disease and severe side branch stenosis. Compared with other 2-stent strategies the double kissing crush (DK-crush) technique has been validated in randomized trials and been associated with fewer major adverse cardiac events (MACE) and target lesion failure (TLF), especially in patients with unprotected left main lesions. ,, Despite its benefits, the DK-crush technique involves multiple steps that be associated with longer procedural times, as well as higher contrast and radiation doses. , The mini-crush technique requires fewer steps, but clinical data supporting its efficacy and safety remain limited. We compared procedural, in-hospital, and long-term outcomes of mini-crush vs DK-crush in bifurcation PCI in a multicenter bifurcation registry.
Methods
This was an observational, cohort study performed across 7 centers in the United States, Russia, and Turkey between 2013-2025 (different centers joined at different times), as part of the Prospective Global Registry of Percutaneous Coronary Intervention in Bifurcation Lesions (PROGRESS-BIFURCATION, NCT05100992). Patients undergoing 2-stent bifurcation PCI using the mini-crush technique were compared with patients treated with the DK-crush technique. The study was approved by the institutional review board of each center. Figure 1 displays procedural steps of mini-crush versus DK-crush technique. The DK Crush technique begins with wiring and predilation of both the main vessel (MV) and side branch (SB), followed by deployment of the SB stent with slight protrusion into the MV. This protruding segment is then crushed using a balloon in the MV. After rewiring the SB through the crushed stent struts, the first kissing balloon inflation (KBI) is performed. The MV stent is subsequently deployed across the SB ostium, followed by proximal optimization technique (POT). A second rewiring of the SB is performed, and a second KBI is performed. The procedure concludes with a final POT.
Procedural steps of mini-crush versus DK-crush techniques.
For mini-crush technique, these steps are streamlined and very based on whether a 6-Fr or 7-Fr guide catheter is used. When using a 6-Fr guide catheter, after wiring both the MV and SB, the SB stent is deployed with minimal protrusion. A balloon positioned in the MV is then inflated to crush the protruding segment of the SB stent against the vessel wall. This is followed by deployment of the MV stent across the SB ostium. A single rewiring of the SB is performed through the MV stent struts, enabling a KBI and final POT. When using a 7-Fr guide catheter, after wiring both the MV and SB, sequential stenting can be performed, in which the SB stent is deployed with minimal protrusion, and after removal of the stent balloon, a stent is deployed in the MV across the SB ostium. A single rewiring of the SB is performed through the MV stent struts, enabling a KBI and final POT.
Definitions
Bifurcation lesions were defined as coronary artery stenoses occurring adjacent to and/or involving the origin of a significant (>1.5 mm) SB. Technical success was defined as the achievement of <30% residual diameter stenosis and thrombolysis in myocardial infarction (TIMI) 3 flow in both MV and SB (when SB PCI was attempted). Procedural success was defined as the achievement of technical success without any in-hospital major adverse cardiac events (MACE). In-hospital MACE was defined as the composite of all-cause mortality, myocardial infarction (MI), urgent repeat revascularization with either PCI or coronary artery bypass graft (CABG) surgery, and cardiac tamponade requiring either pericardiocentesis or surgery prior to hospital discharge. MI was defined using the Third Universal Definition of Myocardial Infarction (type 4a MI). Long-term MACE was defined as composite of all-cause mortality, MI, stroke, target-vessel revascularization with either PCI or CABG.
Statistical analysis
Categorical variables were expressed as n (percentages) and were compared using the Pearson’s chi-square test. Continuous variables are presented as mean ± standard deviation or as median (interquartile range) and were compared using the independent-samples t-test for normally distributed variables and the Mann-Whitney U test for nonparametric variables, as appropriate. The effect of mini-crush technique versus DK-crush on follow-up MACE. Long-term outcomes were based on Kaplan-Meier estimates in time-to-first-event analysis with log-rank test and mixed effects Cox proportional hazard ratios (HR). HRs were adjusted for confounding. Univariable logistic regression was performed to identify variables associated with MACE; next, variables showing statistical significance (p < 0.10) were filtered by clinical/angiographic significance. Variables with statistical, clinical, and angiographic significance were included in the multivariable analysis.
In addition, propensity score matching analysis was also conducted to minimize potential confounding in the study outcomes. A total of 8 variables were incorporated into the analysis, including age, gender, comorbidities, left main stenosis, prevalence of acute coronary syndromes, and usage of intravascular imaging. To account for missing data, we used multiple imputation, generating and analyzing 5 imputed datasets. The propensity score matching was performed using the Within approach. Nearest neighbor matching was used with a 1:1 ratio, and covariate balance between the matched groups was evaluated through standardized differences. All statistical analyses were performed using R Statistical Software, version 4.4.0 (R Foundation for Statistical Computing, Vienna, Austria). A p-value of < 0.05 was considered statistically significant.
Results
Among 2,508 bifurcation lesions treated with PCI in 2,284 patients, 184 (7.3%) used the mini-crush technique and 257 (10.2%) used the DK crush technique. Compared with patients treated with DK-crush, those treated with mini-crush had similar age (69.8 ± 11.7 vs 68.0 ± 12.0), and proportion of men (73.9 % vs 77.4%), as well as comorbidities such as hypertension, diabetes, dyslipidemia, heart failure, prior PCI, prior MI, and prior CABG ( Table 1 ).
Table 1
Comparison of baseline clinical characteristics of patients who underwent bifurcation PCI using the DK-crush versus the mini-crush techniques
| Variables |
DK crush
(n = 198) |
Mini-crush
(n = 139) |
p-value |
|---|---|---|---|
| Age (years) | 68.02 ± 11.98 | 69.79 ± 11.66 | 0.222 |
| Gender, male | 77.4% (151) | 73.9% (102) | 0.459 |
| BMI | 29.80 ± 5.68 | 28.97 ± 5.95 | 0.180 |
| Diabetes mellitus | 36.2% (71) | 42.8% (59) | 0.228 |
| Hypertension | 75.0% (147) | 76.8% (106) | 0.704 |
| Dyslipidemia | 81.1% (159) | 88.4% (122) | 0.073 |
| Smoking, current | 22.7% (45) | 22.3% (31) | 0.927 |
| Left ventricular ejection fraction (%) | 52.26 ± 13.14 | 51.85 ± 12.24 | 0.446 |
| Family history of CAD | 15.6% (30) | 18.4% (25) | 0.510 |
| Heart failure | 26.3% (51) | 23.4% (32) | 0.545 |
| Prior PCI | 44.9% (88) | 50.7% (69) | 0.295 |
| Prior MI | 34.0% (66) | 40.4% (55) | 0.234 |
| Cerebrovascular disease | 13.8% (27) | 10.9% (15) | 0.420 |
| Peripheral arterial disease | 10.3% (20) | 14.5% (20) | 0.241 |
| CAD presentation | 0.226 | ||
| Stable angina | 35.6% (69) | 33.8% (45) | |
| Unstable angina | 20.1% (39) | 11.3% (15) | |
| NSTEMI | 26.8% (52) | 33.8% (45) | |
| STEMI | 8.2% (16) | 12.8% (17) | |
| No symptoms | 8.8% (17) | 7.5% (10) | |
| Nonischemic symptoms | 0.5% (1) | 0.8% (1) | |
| Baseline creatinine (mg/dL) | 1.00 [0.85, 1.20] | 0.97 [0.81, 1.21] | 0.863 |
CAD = coronary artery disease; CABG = coronary artery bypass graft; MI = myocardial infarction; NSTEMI = non-ST segment elevation myocardial infarction; PCI = percutaneous coronary intervention; STEMI = ST segment elevation myocardial infarction.
Compared to DK-crush, patients undergoing mini-crush stenting had a significantly higher incidence of proximal main vessel tortuosity and longer lesion lengths in both the main vessel and side branch. In addition, mini-crush was less frequently applied to left main bifurcations (25.5% vs 35.8%; p = 0.03), underscoring a key anatomical divergence. Pretreatment intravascular imaging was utilized nearly twice as often in the DK-crush group (41.9% vs 21.3%; p < 0.001), reflecting a more imaging-guided approach. Furthermore, final kissing balloon inflation (KBI) was performed in nearly all DK-crush cases (99.4%), compared to a significantly lower rate in the mini-crush group (86.3%; p<0.001). Angiographic and procedural distinctions between the study groups are detailed in Table 2 .
Table 2
Angiographic characteristics of patients who underwent bifurcation PCI using the DK-crush versus the mini-crush technique
| Variables |
DK crush
(n = 257) |
Mini-crush
(n = 184) |
p-value |
|---|---|---|---|
| LM stenosis (%) | 20.00 [0.00, 70.00] | 0.00 [0.00, 50.00] | 0.002 |
| Proximal LAD stenosis (%) | 80.00 [50.00, 90.00] | 80.00 [60.00, 90.00] | 0.407 |
| Mid‐distal LAD, diagonal stenosis (%)) | 80.00 [60.00, 90.00] | 80.00 [60.00, 90.00] | 0.717 |
| CIRC, OM, LPDA, LPL branches stenosis (%) | 80.00 [30.00, 90.00] | 70.00 [30.00, 90.00] | 0.026 |
| RCA, RPDA, RPL branches stenosis (%) | 60.00 [20.00, 99.00] | 50.00 [0.00, 90.00] | 0.098 |
| Ostial lesion (within 5 mm of aortocoronary ostium) | 13.9% (34) | 14.0% (25) | 0.992 |
| Proximal main vessel | 0.137 | ||
| LMCA | 35.8% (92) | 25.5% (47) | |
| LAD | 41.6% (107) | 48.9% (90) | |
| RCA | 9.7% (25) | 10.9% (20) | |
| Circumflex | 12.1% (31) | 14.7% (27) | |
| Bypass graft | 0.8% (2) | 0.0% (0) | |
| Proximal main vessel diameter (mm) | 3.50 [3.30, 4.00] | 3.50 [3.25, 4.00] | 0.913 |
| Proximal main vessel lesion length (mm) | 8.00 [5.00, 10.00] | 10.00 [5.00, 15.00] | 0.005 |
| Proximal main vessel diameter stenosis (%) | 70.00 [50.00, 90.00] | 80.00 [60.00, 90.00] | 0.539 |
| Distal main vessel diameter (mm) | 3.00 [3.00, 3.50] | 3.00 [2.75, 3.50] | 0.112 |
| Distal main vessel lesion length (mm) | 10.00 [7.00, 20.00] | 15.00 [8.00, 20.00] | 0.078 |
| Proximal main vessel tortuosity | < 0.001 | ||
| Straight (< 70 degrees, 1 Bend) | 66.9% (172) | 52.7% (97) | |
| Slight (>70 degrees, 1 Bend) | 21.4% (55) | 37.5% (69) | |
| Moderate (2 Bends >70 degrees or 1 Bend >90 degrees) | 8.6% (22) | 9.8% (18) | |
| Severe (2 Bends >90 degrees or 1 Bend >120 degrees) | 3.1% (8) | 0.0% (0) | |
| Side branch diameter (mm) | 2.75 [2.50, 3.00] | 2.50 [2.50, 3.00] | 0.471 |
| Side branch lesion length (mm) | 10.00 [5.00, 15.00] | 12.00 [8.00, 20.00] | < 0.001 |
| Distal main vessel diameter stenosis (%) | 80.00 [70.00, 90.00] | 80.00 [70.00, 90.00] | 0.983 |
| Calcification | 0.109 | ||
| None | 22.2% (57) | 31.0% (57) | |
| Mild (Spots) | 26.1% (67) | 22.8% (42) | |
| Moderate (≤50% reference lesion diameter) | 26.1% (67) | 19.0% (35) | |
| Severe (>50% reference lesion diameter) | 25.7% (66) | 27.2% (50) | |
| Medina classification | 0.327 | ||
| 1,1,1 | 65.4% (168) | 74.5% (137) | |
| 1,1,0 | 9.7% (25) | 6.5% (12) | |
| 1,0,1 | 5.4% (14) | 4.3% (8) | |
| 0,1,1 | 12.1% (31) | 10.3% (19) | |
| 1,0,0 | 0.8% (2) | 1.6% (3) | |
| 0,1,0 | 3.1% (8) | 1.1% (2) | |
| 0,0,1 | 3.5% (9) | 1.6% (3) | |
| Side branch diameter stenosis (%) | 80.00 [70.00, 90.00] | 80.00 [80.00, 90.00] | 0.226 |
| Pretreatment IVUS/OCT | 41.9% (106) | 21.3% (39) | < 0.001 |
| Technical success | 98.8% (254) | 98.4% (181) | 0.697 |
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