Comparison of clinical outcomes of intravascular ultrasound-calcified nodule between percutaneous coronary intervention with versus without rotational atherectomy in a propensity-score matched analysis

Coronary calcified nodules versus nonnodular coronary calcifications: a systematic review and meta-analysis

BACKGROUND

Percutaneous coronary intervention (PCI) on severely calcified coronary lesions is challenging. Coronary calcified nodule (CN) refers to an eccentric and protruding coronary calcification associated with plaque vulnerability and adverse clinical events. This study aims to conduct an extensive review of CNs, focusing on its prognostic impact in comparison with nonnodular coronary calcification (N-CN).

METHOD

A systematic literature review on PubMed, MEDLINE, and EMBASE databases was conducted for relevant articles. Observational studies or randomized controlled trials comparing CNs and N-CNs were included.

RESULTS

Five studies comparing CNs and N-CNs were pertinent for inclusion. The total number of individuals across these studies was 1456. There were no significant differences in the baseline demographic, clinical, and angiographic data between the CN and N-CN groups. Intracoronary imaging was always utilized. At follow-up, CNs were associated with significantly increased, target vessel revascularization [odds ratio (OR) 2.16; 95% confidence interval (CI): 1.39-3.36, P-value < 0.01, I2 = 0%] and stent thrombosis (OR 9.29; 95% CI: 1.67-51.79, P-value = 0.01, I2 = 0%) compared with N-CN. A trend for greater cardiac death was also assessed in the CN group (OR 1.75; 95% CI: 0.98-3.13, P-value = 0.06, I2 = 0%).

CONCLUSION

CN has a significantly negative impact on outcomes when compared with N-CN.

Distinct Challenges of Eruptive and Non-Eruptive Calcified Nodules in Percutaneous Coronary Intervention

PURPOSE OF REVIEW

To provide a summary of prevalence, pathogenesis, and treatment of coronary calcified nodules (CNs).

RECENT FINDINGS

CNs are most frequently detected at the sites of hinge motion of severely calcified lesions such as in the middle segment of right coronary artery and left main coronary bifurcation. On histopathology, CNs exhibit two distinctive morphologies: eruptive and non-eruptive. Eruptive CNs, which have a disrupted fibrous cap with adherent thrombi, are biologically active. Non-eruptive CNs, which have an intact fibrous cap without thrombi, are biologically inactive, representing either healed eruptive CNs or protrusion of calcium due to plaque progression. Recent studies using optical coherence tomography (OCT) have shown a difference in the mechanism of stent failure in the two subtypes, demonstrating early reappearance of eruptive CNs in the stent (at ~ 6 months) as a unique mechanism of stent failure that does not seem to be preventable by simply achieving adequate stent expansion. The cause of CN reappearance in stent is not known and could be due to acute or subacute intrusion or continued growth of the CN. Whether modification of CN is needed, the most effective calcium modification modality and effectiveness of stent implantation in eruptive CNs has not been elucidated. In this review, we discuss pathogenesis of CNs and how intravascular imaging can help diagnose and manage patients with CNs. We also discuss medical and transcatheter therapies beyond conventional stent implantation for effective treatment of eruptive CNs that warrant testing in prospective studies.

Calcified Nodule in Percutaneous Coronary Intervention: Therapeutic Challenges

Calcified nodules (CNs) are among the most challenging lesions to treat in contemporary percutaneous coronary intervention. CNs may be divided into 2 subtypes, eruptive and noneruptive, which have distinct histopathological and prognostic features. An eruptive CN is a biologically active lesion with a disrupted fibrous cap and possibly adherent thrombus, whereas a noneruptive CN has an intact fibrous cap and no adherent thrombus. The use of intravascular imaging may allow differentiation between the 2 subtypes, thus potentially guiding treatment strategy. Compared with noneruptive CNs, eruptive CNs are more likely to be deformable, resulting in better stent expansion, but are paradoxically associated with worse clinical outcomes, in part because of their frequent initial presentation as an acute coronary syndrome and subsequent reprotrusion of the CN into the vessel lumen through the stent struts. Pending the results of ongoing studies, a tailored therapeutic approach based on the distinct features of the different CNs may be of value.

Comparison of interventional treatment options for coronary calcified nodules: A sub-analysis of the ROTA.shock trial

BACKGROUND

The optimal treatment for coronary calcified nodules (CNs) is still unclear. The aim of this study was to compare the modification of these lesions by coronary intravascular lithotripsy (IVL) and rotational atherectomy (RA) using optical coherence tomography (OCT).

METHODS

ROTA.shock was a 1:1 randomized, prospective, double-arm multi-center non-inferiority trial that compared the use of IVL and RA with percutaneous coronary intervention (PCI) in severely calcified lesions. In 19 of the patients out of this study CNs were detected by OCT in the target lesion and were treated by either IVL or RA.

RESULTS

The mean angle of CNs was significantly larger in final OCT scans than before RA (92 ± 17° vs. 68 ± 7°; p = 0.01) and IVL (89 ± 18° vs. 60 ± 10°; p = 0.03). The CNs were thinner upon final scans than in initial native scans (RA: 17.8 ± 7.8 mm vs. 38.6 ± 13.1 mm; p = 0.02; IVL: 16.5 ± 9.0 mm vs. 37.2 ± 14.3 mm; p = 0.02). Nodule volume did not differ significantly between native and final OCT scans (RA: 0.66 ± 0.12 mm3 vs. 0.61 ± 0.33 mm3; p = 0.68; IVL: 0.64 ± 0.19 mm3 vs. 0.68 ± 0.22 mm3; p = 0.74). Final stent eccentricity was high with 0.62 ± 0.10 after RA and 0.61 ± 0.09 after IVL.

CONCLUSION

RA or IVL are unable to reduce the volume of the calcified plaque. CN modulation seems to be mainly induced by the stent implantation and not by RA or IVL.

Secondary rotational atherectomy is associated with reduced occurrence of prolonged ST-segment elevation following ablation

Elevation of the ST segment after percutaneous coronary intervention (PCI) using rotational atherectomy (RA) for severely calcified lesions often persists after disappearance of the slow-flow phenomenon on angiography. We investigated clinical factors relevant to prolonged ST-segment elevation following RA among 152 patients with stable angina undergoing elective PCI. PCI procedures were divided into two strategies, RA without (primary RA strategy) or with (secondary RA strategy) balloon dilatation before RA. Incidence of prolonged ST-segment elevation after disappearance of slow-flow phenomenon was higher in the 56 patients with primary RA strategy (13%) than in the 96 patients with secondary RA strategy (3%, p = 0.039). Univariate logistic regression analysis showed levels of low-density lipoprotein cholesterol (LDL-C) (odds ratio [OR] 0.95, 95% confidence interval [CI] 0.93-0.99; p = 0.013), levels of triglycerides (OR 0.97, 95%CI 0.94-0.99; p = 0.040), and secondary RA strategy (OR 0.23, 95% CI 0.05-0.85; p = 0.028) were inversely associated with occurrence of prolonged ST-segment elevation following ablation. However, hemodialysis, diabetes mellitus, left-ventricular ejection fraction, lesion length ≥ 20 mm, and burr size did not show significant associations. Multivariate logistic regression analysis modeling revealed that secondary RA strategy was significantly associated with the occurrence of prolonged ST-segment elevation (Model 1: OR 0.24, 95% CI 0.05-0.95, p = 0.042; Model 2: OR 0.17, 95% CI 0.03-0.68, p = 0.018; Model 3: OR 0.21, 95% CI 0.03-0.87, p = 0.041) even after adjusting for levels of LDL-C and triglycerides. Secondary RA strategy may be useful to reduce the occurrence of prolonged ST-segment elevation following RA.

Lifetime management of severely calcified coronary lesions: the treatment algorithm focused on the shape of calcification

The concept of lifetime management has not been discussed in the field of percutaneous coronary intervention (PCI), because the durability of drug-eluting stent (DES) is considered to be long enough for most patients. Furthermore, even if in-stent restenosis occurs, the treatment for in-stent restenosis is simple in most cases. On the other hand, the long-term clinical outcomes after DES implantation are worse in severely calcified coronary lesions than in non-calcified lesions. Moreover, the treatment for in-stent calcified restenosis or restenosis due to stent underexpansion is not simple. The concept of lifetime management of severely calcified lesions may be necessary like that of aortic stenosis. Recently, several algorithms have been published in PCI to severely calcified lesions, partly because of the emergence of IVL. These algorithms focus on the selection of cracking and debulking devices for the preparation of stenting. However, the optimal stent expansion does not guarantee the long-term patency, when the target lesion includes calcified nodules. Stent restenosis due to calcified nodules is difficult to manage. In this review article, we propose the algorithm for severely calcified lesions focused on the shape of calcification. We do not need to hesitate stenting when multiple cracks on circumferential calcification are observed by intravascular imaging devices. However, DCB may be an option as final device in some situations, when lifetime management of severely calcified lesions is considered.

Rotational atherectomy of calcified coronary lesions: current practice and insights from two randomized trials

With growing experience, technical improvements and use of newer generation drug-eluting stents (DES), recent data showed satisfactory acute and long-term results after rotational atherectomy (RA) in calcified coronary lesions. The randomized ROTAXUS and PREPARE-CALC trials compared RA to balloon-based strategies in two different time periods in the DES era. In this manuscript, we assessed the technical evolution in RA practice from a pooled analysis of the RA groups of both trials and established a link to further recent literature. Furthermore, we sought to summarize and analyze the available experience with RA in different patient and lesion subsets, and propose recommendations to improve RA practice. We also illustrated the combination of RA with other methods of lesion preparation. Finally, based on the available evidence, we propose a simple and practical approach to treat severely calcified lesions.

The role of invasive and non-invasive imaging technologies and calcium modification therapies in the evaluation and management of coronary artery calcifications

The treatment of coronary artery disease (CAD) has advanced significantly in recent years due to improvements in medical therapy and percutaneous or surgical revascularization. However, a persistent obstacle in the percutaneous management of CAD is coronary artery calcification (CAC), which portends to higher rates of procedural challenges, post-intervention complications, and overall poor prognosis. With the advent of novel multimodality imaging technologies spanning from intravascular ultrasound to optical coherence tomography to coronary computed tomography angiography combined with advances in calcium debulking and modification techniques, CACs are now targets for intervention with growing success. This review will summarize the most recent developments in the diagnosis and characterization of CAC, offer a comparison of the aforementioned imaging technologies including which ones are most suitable for specific clinical presentations, and review the CAC modifying therapies currently available.

Clinical expert consensus document on rotational atherectomy from the Japanese association of cardiovascular intervention and therapeutics: update 2023

The Task Force on Rotational Atherectomy of the Japanese Association of Cardiovascular Intervention and Therapeutics (CVIT) proposed the expert consensus document to summarize the techniques and evidences regarding rotational atherectomy (RA) in 2020. Because the revascularization strategy to severely calcified lesions is the hottest topic in contemporary percutaneous coronary intervention (PCI), many evidences related to RA have been published since 2020. Latest advancements have been incorporated in this updated expert consensus document.

Characteristics and Pattern of Calcified Nodule and/or Nodular Calcification Detected by Intravascular Ultrasound on the Device-Oriented Composite Endpoint (DoCE) in Patients with Heavily Calcified Lesions Who Underwent Rotational Atherectomy-Assisted Percutaneous Coronary Intervention

Objectives

This study aimed to determine characteristics and pattern of a calcified nodule (CN) and/or nodular calcification (NC) detected by intravascular ultrasound (IVUS) on the device-oriented composite endpoint (DoCE) in patients with calcified lesions who underwent rotational atherectomy (RA)-assisted percutaneous coronary intervention (PCI).

Background

The characteristics and pattern of a CN and/or NC on clinical outcome remain unknown.

Methods

We retrospectively enrolled patients who underwent RA-assisted PCI at Siriraj Hospital during August 2016 to April 2020. Preprocedural IVUS imaging was mandatory. CN/NC was defined as convex shape of luminal surface and luminal side of calcium with protrusion into the coronary artery lumen as assessed by IVUS. The primary outcome was cumulative of DoCE, defined as the composite of cardiovascular death, myocardial infarction, and clinically-driven target lesion revascularization.

Results

Two hundred patients were included. Primary outcome occurred in 14%. The cumulative DoCE was significantly higher in the CN/NC group than that in the non-CN/NC group (20.7% vs. 8.8%, p = 0.022). CN/NC (p = 0.023) and MSA ≤ 5.5 mm² (p = 0.047) were correlated with a significantly higher cumulative DoCE. CN/NC was the independent predictor for the cumulative DoCE (HR = 2.96, 95% CI 1.08-8.11, p = 0.035). Pattern and characteristic of CN/NC have a prognostic value. Patients with an eccentric CN/NC had a significantly higher cumulative DoCE compared to those CN/NC with concentric calcification (p = 0.014).

Conclusion

The presence of a CN/NC in patients with heavily calcified lesions who underwent RA-assisted PCI was found to be associated with increased cumulative 5 year DoCE, especially in patients with an eccentric CN/NC. The clinical trial is registered with TCTR20210616001.

Prediction of optical coherence tomography-detected calcified nodules using coronary computed tomography angiography

Diagnosis of calcified nodules (CNs) is critical in the proper management of coronary artery disease, but CNs can be detected only using intracoronary imaging modalities. This study aimed to investigate the ability of coronary computed tomography angiography (CCTA) in predicting CNs detected using optical coherence tomography (OCT). From 138 patients who underwent OCT-guided percutaneous coronary intervention (PCI) after CCTA evaluation, 141 PCI target vessels were retrospectively enrolled and classified into CN (12 vessels/11 patients; CNs in the PCI culprit lesion) and non-CN (129 vessels/127 patients; without CNs) groups based on the OCT analysis. Retrospective CCTA analysis revealed significantly higher coronary artery calcification score (CACS), calcified plaque volume (CPV), and maximum calcified plaque area (MCPA) of the target vessel in the CN group than in the non-CN group. Receiver operating characteristic curve indicated that CACS ≥ 162 (area under the ROC curve (AUC 0.76, sensitivity 83.3%, specificity 54.2%), CPV ≥ 20.1 mm³ (AUC 0.83, sensitivity 100%, specificity 57.3%), and MCPA ≥ 4.51 mm² (AUC 0.87, sensitivity 91.7%, specificity 78.3%) were the best cutoff values for predicting CNs. MCPA showed the highest AUC among all the CCTA parameters. In conclusion, CCTA is useful for predicting OCT-detected CNs in PCI target vessels.

Impact of ultrasound reverberation in calcified coronary arteries: Intravascular ultrasound study

BACKGROUND AND AIMS

Intravascular ultrasound (IVUS) often allows us to observe reverberations behind calcification in percutaneous coronary intervention (PCI) to heavily calcified lesions. However, clinical significance of reverberations remains unknown. The aim of this study was to assess the impact of reverberations on stent expansion and clinical outcomes after PCI with rotational atherectomy (RA) to heavily calcified lesions.

METHODS

We considered 250 calcified lesions that underwent IVUS-guided PCI with RA. According to the number of reverberations (NR), those lesions were divided into the high NR (≥3) group (n = 36) and the low NR (≤2) group (n = 214). Stent expansion and the cumulative incidence of ischemia-driven target lesion revascularization (ID-TLR) were compared between the high and low NR groups.

RESULTS

The high NR group showed significantly smaller stent expansion rate than the low NR group (67.7% vs. 75.9%, respectively, p=0.02). The multivariate logistic regression analysis showed that high NR and calcified nodule were significantly associated with stent underexpansion. The incidence of ID-TLR was significantly higher in the high NR group than in the low NR group (p=0.03). In multivariate Cox hazard analysis, high NR and acute coronary syndrome were significantly associated with ID-TLR.

CONCLUSIONS

High NR was significantly associated with stent underexpansion and ID-TLR. When high NR was detected by IVUS, the PCI strategy was be planned carefully to avoid stent underexpansion. The follow-up program of the patients with high NR might need to be scheduled prudently because of the high risk of TLR.

Clinical Outcomes and Unique Restenosis of Calcified Nodule in Heavily Calcified Coronary Artery

AIMS

Calcified nodule (CN) has been known as the advanced stage of coronary calcification. However, clinical outcomes following percutaneous coronary intervention (PCI) to CN remain unknown. This study aimed to compare clinical outcomes, including target lesion revascularization (TLR), between calcified coronary lesions with and without CN.

METHODS

Two hundred forty-nine lesions undergoing intravascular ultrasound-guided PCI with rotational atherectomy (RA) were enrolled and divided into the CN group (n=100) and the non-CN group (n=149) according to the presence of CN. The cumulative incidence of clinically driven TLR (CD-TLR) and the reasons for CD-TLR were compared between the CN and non-CN groups.

RESULTS

The incidence of CD-TLR was significantly higher in the CN group than in the non-CN group. In the landmark analysis at 1 year, the CN group showed a significantly higher incidence of CD-TLR within 1 year. However, the incidence of CD-TLR beyond 1 year was numerically lower in the CN group than in the non-CN group. In the multivariate Cox hazard model, CN was significantly associated with CD-TLR. In the CN group, in-stent CN was the major reason for CD-TLR (52%) and was observed mainly within 1 year (90%).

CONCLUSIONS

In the heavily calcified lesions requiring RA, CN was the factor associated with the higher rate of CD-TLR especially within 1 year. The timing of CD-TLR in lesions with CN may indicate that the process of CN protruding through the struts was progressed monthly.

Incidence and prognostic impact of the calcified nodule in coronary artery disease patients with end-stage renal disease on dialysis

Coronary artery calcification is frequently observed in coronary artery disease (CAD) patients with end-stage renal disease (ESRD). Calcified nodule (CN) is recognized as one of the vulnerable plaque characteristics responsible for acute coronary syndrome (ACS). Although CN is a cause of ACS in only 10%, its prevalence may be higher in elderly patients and/or ESRD. The aim of this study is to investigate incidence, clinical characteristics, and prognostic impact of CN in CAD patients with ESRD on dialysis. A total of 51 vessels from 49 CAD patients with ESRD on dialysis were enrolled in this study. CN was defined as a high-backscattering mass protruding into the lumen with a strong signal attenuation and an irregular surface by optical coherence tomography. Incidence, clinical characteristics and prognosis of patients with CN were studied. Major adverse cardiac events (MACE) were defined as a composite of all-cause death, non-fatal myocardial infarction, target vessel revascularization (TVR) and stroke. CNs were observed in 30 vessels from 29 patients (59.2%). Duration of dialysis was significantly longer in CN group than in non-CN group (P = 0.03). Overall, all-cause death, cardiac death, TVR and MACE occurred in 7 (14.3%), 3 (6.1%), 11 (22.4%) and 16 (32.7%) patients during follow-up (median 826 days), respectively. Kaplan-Meier survival analysis revealed that MACE-free survival was significantly lower in patients with CN compared with those without CN (Log-rank, P = 0.036).In conclusion, CN was observed in about 60% of the CAD patients with ESRD and was associated with duration of dialysis and worse prognosis.

Intravascular ultrasound-factors associated with slow flow following rotational atherectomy in heavily calcified coronary artery

Intravascular ultrasound (IVUS) can provide useful information in patients undergoing complex percutaneous coronary intervention with rotational atherectomy (RA). The association between IVUS findings and slow flow following rotational atherectomy (RA) has not been investigated, although slow flow has been shown to be an unfavorable sign with worse outcomes. The aim of this study was to determine the IVUS-factors associated with slow flow just after RA. We retrospectively enrolled 290 lesions (5316 IVUS-frames) with RA, which were divided into the slow flow group (n = 43 with 1029 IVUS-frames) and the non-slow flow group (n = 247 with 4287 IVUS-frames) based on the presence of slow flow. Multivariate regression analysis assessed the IVUS-factors associated with slow flow. Slow flow was significantly associated with long lesion length, the maximum number of reverberations [odds ratio (OR) 1.49; 95% confidence interval (CI) 1.07–2.07, p = 0.02] and nearly circumferential calcification at minimal lumen area (MLA) (≥ 300°) (OR, 2.21; 95% CI 1.13–4.32; p = 0.02). According to the maximum number of reverberations, the incidence of slow flow was 2.2% (n = 0), 11.9% (n = 1), 19.5% (n = 2), 22.5% (n = 3), and 44.4% (n = 4). In conclusion, IVUS findings such as longer lesion length, the maximum number of reverberations, and the greater arc of calcification at MLA may predict slow flow after RA. The operators need to pay more attention to the presence of reverberations to enhance the procedure safety.

Safety and procedural outcomes of intravascular lithotripsy in calcified coronaries in Indian patients

Objective

Calcified coronaries still remain a major challenge for interventional cardiologist. This study aims to evaluate safety and efficacy of intravascular lithotripsy (IVL) in management of coronary artery calcification.

Methods

This was a retrospective single centre study regarding the utility of IVL in management of calcified coronaries. Patients with hemodynamically stable acute coronary syndrome or symptomatic chronic coronary syndrome (CCS) and calcified coronaries on angiography and who underwent IVL were enrolled. Intravascular imaging was performed wherever feasible. The primary endpoint was procedural success. In addition, data regarding procedural complications were collected.

Results

A total of 29 patients underwent IVL with a majority being males and having comorbidities such as hypertension and diabetes. A procedural success rate of 93.1% was achieved with no patient having >50% residual stenosis. IVL catheter was successfully delivered in all patients. The mean catheter diameter was 3.3 ± 0.4 mm and mean number of delivered pulses was 70.3 ± 16.4. The arteries most commonly intervened were the left main coronary and the left anterior descending artery. Intracoronary imaging revealed a significant increase in minimum luminal cross-sectional area (MLA) post IVL (pre-MLA: 5.1 ± 2.5 mm²; post-MLA: 10.7 ± 2.9 mm²; P<0.001). Two patients had in-hospital MACE in form of peri-procedural non Q-wave MI. No patient had arrhythmias, stent thrombosis, coronary perforation, or slow flow/no-reflow. Two patients had a rupture of IVL balloon while four had coronary artery dissection.

Conclusions

IVL is a safe and highly effective modality with high procedural success rate in management of calcified coronaries.

Modifiable and unmodifiable factors associated with slow flow following rotational atherectomy

Background

Although several groups reported the risk factors for slow flow during rotational atherectomy (RA), they did not clearly distinguish modifiable factors, such as burr-to-artery ratio from unmodifiable ones, such as lesion length. The aim of this retrospective study was to investigate the modifiable and unmodifiable factors that were associated with slow flow.

Methods

We included 513 lesions treated with RA, which were classified into a slow flow group (n = 97) and a non-slow flow group (n = 416) according to the presence or absence of slow flow just after RA. The multivariate logistic regression analysis was performed to find factors associated with slow flow.

Results

Slow flow was inversely associated with reference diameter [Odds ratio (OR) 0.351, 95% confidence interval (CI) 0.205–0.600, p<0.001], primary RA strategy (OR 0.224, 95% CI 0.097–0.513, p<0.001), short single run (≤15 seconds) (OR 0.458, 95% CI 0.271–0.776, p = 0.004), and systolic blood pressure (BP) ≥ 140 mmHg (OR 0.501, 95% CI 0.297–0.843, p = 0.009). Lesion length (every 5 mm increase: OR 1.193, 95% CI 1.093–1.301, p<0.001), angulation (OR 2.054, 95% CI 1.171–3.601, p = 0.012), halfway RA (OR 2.027, 95% CI 1.130–3.635, p = 0.018), initial burr-to-artery ratio (OR 1.451, 95% CI 1.212–1.737, p<0.001), and use of beta blockers (OR 1.894, 95% CI 1.004–3.573, p = 0.049) were significantly associated with slow flow.

Conclusions

Slow flow was positively associated with several unmodifiable factors including lesion length and angulation, and inversely associated with reference diameter. In addition, slow flow was positively associated with several modifiable factors including initial burr-to-artery ratio and use of beta blockers, and inversely associated with primary RA strategy, short single run, and systolic blood pressure just before RA. Application of this information could help to improve RA procedures.

Acute Angulation and Sequential Lesion Increase the Risk of Rotational Atherectomy Failure

BACKGROUND

The aim of the study was to assess anatomical and procedural predictors of clinical and procedural failure of rotational atherectomy (RA) in an all-comers population.Methods and Results:A total of 534 consecutive patients who underwent RA were included in a double-center observational study. The primary composite endpoint consisted of: rota-wire introduction failure, burr-passage failure, periprocedural complications and procedure-related major adverse events. The second primary endpoint included rota-wire introduction failure and burr-passage failure. The primary endpoint occurred in 76 (14.2%) patients and the second primary endpoint occurred in 64 (12%) Periprocedural complications occurred in 23 (4.3%) and procedure-related adverse events in 23 (4.3%) patients. Multivariable analysis revealed angulation on lesion ≤90° (HR=2.18, 95% CI: 1.21-3.94, P=0.0096) and sequential lesion (HR=1.89, 95% CI: 1.01-3.54, P=0.046) as independent predictors of no clinical success of RA. Multivariable analysis revealed again that angulation on lesion ≤90° (HR=2.26, 95% CI: 1.16-4.40, P=0.02) and sequential lesion (HR=3.77, 95% CI: 1.64-8.69, P<0.01) as independent predictors of no procedural success of RA.

CONCLUSIONS

The presence of an acute angulation on lesion and sequential lesion are independent determinants of clinical and procedural failure of RA. Further research is necessary to establish a score predicting RA failure, which can help in preproceduralrisk stratification of patients undergoing complex percutaneous coronary intervention with RA.