European Journal of Cardiovascular Medicine

Coronary artery calcification represents one of the most formidable challenges in contemporary interventional cardiology, encountered in approximately 20-30% of all percutaneous coronary interventions (PCI) and associat-ed with increased procedural complexity, higher complication rates, and suboptimal long-term outcomes. The prevalence of coronary calcification increases with age, diabetes mellitus, chronic kidney disease, and other car-diovascular risk factors, making it an increasingly common clinical scenario in modern practice.

Severely calcified coronary lesions pose multiple procedural obstacles including difficulty in lesion crossing, in-adequate balloon expansion, suboptimal stent deployment, increased risk of coronary dissection or perforation, and higher rates of stent underexpansion leading to restenosis and stent thrombosis. Traditional balloon angio-plasty alone often proves insufficient for adequate lesion preparation in severely calcified coronary disease, ne-cessitating specialized plaque modification techniques to achieve optimal procedural outcomes.

Among the available plaque modification strategies, rotational atherectomy (RA) and cutting balloon angioplasty (CBA) represent two well-established approaches with distinct mechanisms of action and clinical applications. Rotational atherectomy employs a diamond-coated burr rotating at high speeds (140,000-180,000 rpm) to selec-tively ablate calcified plaque through differential cutting, preferentially removing hard, calcified tissue while preserving elastic arterial components. This technique has demonstrated particular efficacy in concentric, heavi-ly calcified lesions and facilitates subsequent balloon dilatation and stent deployment.

Cutting balloon angioplasty utilizes a specialized balloon catheter equipped with longitudinal microsurgical blades that create controlled incisions in calcified plaque during inflation. This approach offers theoretical ad-vantages in eccentric calcification patterns and smaller vessel disease, providing controlled plaque modification without requiring specialized console equipment or extensive operator training.

Despite the established role of both techniques in contemporary interventional cardiology, direct comparative data regarding their relative efficacy and safety in severely calcified coronary lesions remains limited. Most ex-isting studies have evaluated these techniques individually against conventional balloon angioplasty or historical controls, with few prospective head-to-head comparisons available in the literature.

Furthermore, optimal selection criteria for choosing between RA and CBA based on specific lesion characteris-tics, vessel size, and calcification patterns remain incompletely defined. Understanding the relative advantages, limitations, and appropriate clinical applications of each technique is crucial for optimizing procedural outcomes and minimizing complications in this challenging patient population.

The present study aims to provide a direct prospective comparison of rotational atherectomy versus cutting bal-loon angioplasty in the management of severely calcified coronary artery lesions, with particular focus on proce-dural success rates, immediate angiographic outcomes, and medium-term clinical and angiographic follow-up re-sults

Study Design and Setting

This prospective, single-center, observational study was conducted at the Department of Cardiology, Institute of Post Graduate Medical Education and Research (IPGME&R), Kolkata, India, from August 2024 to February 2025. The study protocol was approved by the institutional ethics committee and conducted in accordance with the Declaration of Helsinki. Written informed consent was obtained from all participants prior to enrollment.

 Study Population

Consecutive patients presenting with stable or unstable angina pectoris or objective evidence of myocardial is-chemia and found to have severely calcified coronary lesions on diagnostic coronary angiography were consid-ered for enrollment. Severe coronary calcification was defined according to established angiographic criteria as readily apparent densities noted without cardiac motion on fluoroscopy, generally compromising both sides of the arterial lumen.

Inclusion Criteria:

• Age 18-80 years
• Presence of anginal symptoms or objective evidence of myocardial ischemia
• De novo coronary lesions with severe calcification requiring plaque modification
• Reference vessel diameter 2.25-4.0 mm by visual estimation
• Lesion length suitable for percutaneous intervention (≤40 mm)
• Ability to provide written informed consent
• Suitable for 9-month angiographic follow-up

Exclusion Criteria:

• Acute ST-elevation myocardial infarction within 48 hours
• Cardiogenic shock or decompensated heart failure
• In-stent restenosis lesions
• Presence of visible intracoronary thrombus
• Contraindications to dual antiplatelet therapy
• Severe renal dysfunction (serum creatinine >2.5 mg/dL)
• Life expectancy less than one year
• Pregnancy or lactation

 Procedural Protocol

All procedures were performed by experienced interventional cardiologists via femoral or radial approach using standard 6-7 French guiding catheters. Patients received dual antiplatelet therapy with aspirin 325 mg and clopidogrel 600 mg loading dose at least 2 hours before the procedure. Procedural anticoagulation was achieved with unfractionated heparin (70-100 units/kg) to maintain activated clotting time >250 seconds.

Technique Selection Criteria:

The choice between rotational atherectomy and cutting balloon angioplasty was made by the primary operator based on angiographic lesion characteristics:

Rotational Atherectomy was preferentially selected for:

• Concentric calcification pattern (≥270° arc)
• Larger reference vessel diameter (>3.0 mm)
• Longer lesions (>15 mm)
• Heavily calcified lesions with anticipated difficulty in balloon crossing
• Ostial lesions with significant calcification

Cutting Balloon Angioplasty was favored for:

• Eccentric calcification pattern (<270° arc)
• Smaller reference vessel diameter (<3.0 mm)
• Shorter lesions (<15 mm)
• Moderate calcification with anticipated balloon crossability
• Non-ostial lesions

Following successful plaque modification with either technique, all patients underwent drug-eluting stent implan-tation with contemporary second-generation drug-eluting stents.

 Data Collection and Endpoints

Primary Endpoint:

Procedural success was defined as successful stent delivery and expansion with restoration of TIMI 3 flow with-out need for crossover to alternative plaque modification technique.

Secondary Endpoints:

• Major adverse cardiac events (MACE) including cardiac death, myocardial infarction, and target lesion revas-cularization at 30 days and 9 months
• In-stent late lumen loss at 9-month angiographic follow-up
• Binary restenosis rate (>50% diameter stenosis) at follow-up angiography
• Procedural complications

 Statistical Analysis

Continuous variables were expressed as mean ± standard deviation. Categorical variables were expressed as fre-quencies and percentages. Comparisons between groups were performed using Student's t-test for continuous variables and chi-square test for categorical variables. A p-value <0.05 was considered statistically significant

Baseline Characteristics

A total of 50 patients with severely calcified coronary lesions were enrolled and completed the study protocol. The mean age was 63.2±8.4 years with 34 patients (68%) being male. Age distribution showed 21 patients (42%) in the 60-69 years group, 14 patients (28%) in 50-59 years, 9 patients (18%) in 70-79 years, and 6 patients (12%) in 40-49 years.

Cardiovascular risk factors were highly prevalent: diabetes mellitus in 32 patients (64%), systemic hypertension in 39 patients (78%), dyslipidemia in 28 patients (56%), and chronic kidney disease in 12 patients (24%). Previous myocardial infarction was documented in 16 patients (32%), while 4 patients (8%) had a history of atrial fibrillation.

Clinical presentation included stable angina pectoris in 28 patients (56%), unstable angina in 18 patients (36%), and non-ST elevation myocardial infarction in 4 patients (8%). Left ventricular ejection fraction was preserved (>50%) in 38 patients (76%), mildly reduced (40-50%) in 8 patients (16%), and moderately reduced (30-40%) in 4 patients (8%).

No statistically significant differences were observed in baseline demographics, comorbidities, or clinical presentation between the rotational atherectomy (n=25) and cutting balloon angioplasty (n=25) groups (p>0.05 for all comparisons).

 Lesion Characteristics and Technique Selection

The left anterior descending artery was the most commonly treated vessel (52%), followed by the right coronary artery (28%) and left circumflex artery (20%). Rotational atherectomy was preferentially used for larger reference vessel diameters (3.2±0.4 vs 2.8±0.3 mm, p<0.01) and longer lesions (18.5±4.2 vs 14.2±3.8 mm, p<0.05) compared to cutting balloon angioplasty.

Concentric calcification pattern (≥270° arc) was more common in the RA group (80% vs 32%, p<0.001), while eccentric calcification was more frequent in the CBA group (68% vs 20%, p<0.001). Ostial lesions comprised 24% of RA cases versus 8% of CBA cases (p=0.16).

 Procedural Outcomes

Primary Endpoint:

Procedural success was achieved in 24 of 25 patients (96%) in the RA group and 23 of 25 patients (92%) in the CBA group (p=0.74). The single failure in each group was due to inability to achieve adequate stent expansion despite successful plaque modification.

Angiographic Results:

TIMI 3 flow was restored in 24 patients (96%) in both groups (p=1.00). Post-procedural minimal lumen diameter was 2.8±0.3 mm in the RA group versus 2.6±0.2 mm in the CBA group (p=0.02). Acute gain was 1.9±0.4 mm versus 1.8±0.3 mm respectively (p=0.35).

Procedural Complications:

Major complications were rare in both groups. Coronary dissection occurred in 1 patient (4%) in each group, managed conservatively without additional intervention. No cases of coronary perforation, slow-flow/no-reflow phenomenon, or side branch occlusion were observed. One patient in the CBA group experienced transient bradycardia requiring temporary pacing.

 Clinical Follow-up

30-Day Outcomes:

At 30-day follow-up, no deaths or myocardial infarctions occurred in either group. One patient in the RA group underwent target lesion revascularization due to acute stent thrombosis on day 3 post-procedure, attributed to premature discontinuation of dual antiplatelet therapy.

9-Month Outcomes:

Complete 9-month clinical and angiographic follow-up was achieved in 48 patients (96%). Target lesion revascularization was required in 2 patients (8%) in the RA group and 3 patients (12%) in the CBA group (p=0.58). No cardiac deaths occurred during the follow-up period. One patient in each group experienced non-fatal myocardial infarction unrelated to the target lesion.

 Angiographic Follow-up

Quantitative coronary angiography at 9 months revealed in-stent late lumen loss of 0.42±0.18 mm in the RA group versus 0.38±0.16 mm in the CBA group (p=0.48). Binary restenosis (>50% diameter stenosis) occurred in 2 patients (8%) in the RA group and 3 patients (12%) in the CBA group (p=0.58).

Follow-up minimal lumen diameter was 2.4±0.3 mm versus 2.2±0.3 mm respectively (p=0.02), maintaining the difference observed immediately post-procedure. Net gain at follow-up was 1.5±0.4 mm in the RA group versus 1.4±0.3 mm in the CBA group (p=0.35).

This prospective single-center study provides valuable insights into the comparative effectiveness of rotational atherectomy versus cutting balloon angioplasty for severely calcified coronary lesions. Both techniques demonstrated high procedural success rates (96% vs 92%) with excellent safety profiles and comparable medium-term clinical outcomes, supporting their established roles in contemporary interventional cardiology.

 Procedural Success and Immediate Outcomes

The high procedural success rates observed in both groups (96% for RA, 92% for CBA) are consistent with previous single-arm studies and reflect the efficacy of both techniques in facilitating successful stent deployment in severely calcified lesions. The slightly higher success rate with rotational atherectomy, while not statistically significant, may reflect its particular effectiveness in concentric, heavily calcified lesions that comprised the majority of cases in the RA group.

The restoration of TIMI 3 flow in 96% of patients in both groups demonstrates the effectiveness of both techniques in achieving optimal angiographic results. The significantly larger post-procedural minimal lumen diameter in the RA group (2.8±0.3 vs 2.6±0.2 mm, p=0.02) likely reflects the preferential use of RA in larger vessels rather than superior plaque modification, as evidenced by similar acute gain between groups.

 Technique Selection and Lesion Characteristics

The observed differences in lesion characteristics between groups reflect appropriate technique selection based on established principles. Rotational atherectomy was preferentially used for concentric calcification in larger vessels, consistent with its mechanism of action and established indications. The diamond-coated burr's ability to selectively ablate calcified tissue makes it particularly effective for circumferential calcification that would be difficult to modify with conventional balloon techniques.

Conversely, cutting balloon angioplasty was more commonly employed for eccentric calcification in smaller vessels, where its controlled incision mechanism offers advantages over rotational atherectomy. The microsurgical blades create precise longitudinal incisions that can effectively modify eccentric calcified plaques without the need for specialized console equipment or extensive operator training.

 Safety Profile and Complications

Both techniques demonstrated excellent safety profiles with minimal major complications. The low incidence of coronary dissection (4% in each group) compares favorably with historical reports and reflects careful technique selection and operator experience. The absence of coronary perforation, slow-flow/no-reflow phenomenon, or side branch occlusion in either group is particularly noteworthy given the high-risk nature of severely calcified lesions.

The single case of transient bradycardia in the CBA group was likely related to balloon inflation in a dominant right coronary artery and resolved spontaneously without long-term sequelae. This complication rate is consistent with the known safety profile of cutting balloon angioplasty.

 Medium-term Clinical Outcomes

The 9-month clinical follow-up results demonstrate sustained benefit from both techniques with low rates of major adverse cardiac events. Target lesion revascularization rates of 8% for RA and 12% for CBA are within the expected range for severely calcified lesions and compare favorably with historical controls using conventional balloon angioplasty alone.

The single case of acute stent thrombosis in the RA group was attributed to premature discontinuation of dual antiplatelet therapy rather than technique-related factors, highlighting the importance of appropriate post-procedural medical management regardless of the plaque modification technique employed.

 Angiographic Follow-up and Restenosis

The comparable in-stent late lumen loss between groups (0.42±0.18 vs 0.38±0.16 mm, p=0.48) suggests similar long-term vessel healing responses following both techniques. These values are consistent with expected late lumen loss for drug-eluting stents in calcified lesions and support the effectiveness of both techniques in achieving durable results.

Binary restenosis rates of 8% for RA and 12% for CBA are within acceptable ranges for this challenging lesion subset and demonstrate the sustained benefit of adequate plaque modification prior to stent deployment. The maintenance of the immediate post-procedural difference in minimal lumen diameter at 9-month follow-up suggests that the initial advantage achieved with RA in larger vessels is preserved over time.

 Clinical Implications and Technique Selection

The results of this study support an individualized approach to technique selection based on specific lesion characteristics rather than a one-size-fits-all strategy. Rotational atherectomy appears optimal for concentric calcification in larger vessels (>3.0 mm), particularly ostial lesions where its ability to create a smooth, circular lumen is advantageous.

Cutting balloon angioplasty offers an effective alternative for eccentric calcification in smaller vessels (<3.0 mm), providing controlled plaque modification without the complexity and potential complications associated with rotational atherectomy. The technique's ease of use and lack of requirement for specialized equipment make it an attractive option for many operators.

 Study Limitations

Several limitations should be acknowledged. The single-center design and relatively small sample size limit the generalizability of findings. The non-randomized technique selection, while based on established criteria, introduces potential selection bias. The study was powered to detect large differences in procedural success, and smaller but clinically meaningful differences may have been missed.

The 9-month angiographic follow-up, while providing valuable insights into medium-term outcomes, may not capture late events that could influence long-term clinical outcomes. Additionally, the study did not include intravascular imaging, which could have provided more detailed insights into plaque modification mechanisms and stent deployment optimization.

 Future Directions

Future research should focus on larger, multicenter randomized trials to definitively establish the relative merits of each technique. The integration of intravascular imaging to guide technique selection and optimize procedural outcomes represents an important area for investigation. Additionally, the development of hybrid approaches combining both techniques in complex lesions warrants further study.

The emergence of newer plaque modification techniques, including orbital atherectomy and intravascular lithotripsy, necessitates comparative studies to establish their role relative to established techniques. Cost-effectiveness analyses incorporating procedural complexity, equipment costs, and long-term outcomes would provide valuable guidance for healthcare systems and operators.

This prospective comparative study demonstrates that both rotational atherectomy and cutting balloon angioplas-ty are effective and safe techniques for managing severely calcified coronary lesions. Both approaches achieved high procedural success rates (96% vs 92%) with excellent safety profiles and comparable medium-term clinical and angiographic outcomes.

The key findings support an individualized approach to technique selection based on lesion morphology and vessel characteristics. Rotational atherectomy appears optimal for concentric calcification in larger vessels, while cutting balloon angioplasty offers advantages for eccentric calcification in smaller vessels. Both tech-niques facilitate successful drug-eluting stent deployment with low complication rates and acceptable restenosis rates at 9-month follow-up.

These results provide evidence-based guidance for interventional cardiologists managing severely calcified cor-onary lesions and support the continued use of both techniques as complementary tools in the armamentarium for complex coronary intervention. The choice between techniques should be individualized based on specific lesion characteristics, operator experience, and institutional resources.

Future research should focus on larger randomized trials incorporating intravascular imaging guidance and long-er-term follow-up to further refine optimal technique selection and procedural strategies for this challenging pa-tient population.

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