Intravascular ultrasound enhances the safety of rotational atherectomy

The Usefulness of Intravascular Ultrasound and Optical Coherence Tomography in Patients Treated with Rotational Atherectomy: An Analysis Based on a Large National Registry

BACKGROUND

Intravascular ultrasound (IVUS) and optical coherence tomography (OCT) have been shown to improve the clinical outcomes of percutaneous coronary interventions (PCIs) in selected subsets of patients.

AIM

The aim was to investigate whether the use of OCT or IVUS during a PCI with rotational atherectomy (RA-PCI) will increase the odds for successful revascularization, defined as thrombolysis in myocardial infarction (TIMI) 3 flow.

METHODS

Data were obtained from the national registry of PCIs (ORPKI) maintained by the Association of Cardiovascular Interventions (AISN) of the Polish Cardiac Society. The dataset includes PCIs spanning from January 2014 to December 2021.

RESULTS

A total of 6522 RA-PCIs were analyzed, out of which 708 (10.9%) were guided by IVUS and 86 (1.3%) by OCT. The postprocedural TIMI 3 flow was achieved significantly more often in RA-PCIs guided by intravascular imaging (98.7% vs. 96.6%, p < 0.0001). Multivariable analysis revealed that using IVUS and OCT was independently associated with an increased chance of achieving postprocedural TIMI 3 flow by 67% (odds ratio (OR), 1.67; 95% confidence interval (CI): 1.40-1.99; p < 0.0001) and 66% (OR, 1.66; 95% CI: 1.09-2.54; p = 0.02), respectively. Other factors associated with successful revascularization were as follows: previous PCI (OR, 1.72; p < 0.0001) and coronary artery bypass grafting (OR, 1.09; p = 0.002), hypertension (OR, 1.14; p < 0.0001), fractional flow reserve assessment during angiogram (OR, 1.47; p < 0.0001), bifurcation PCI (OR, 3.06; p < 0.0001), and stent implantation (OR, 19.6, p < 0.0001).

CONCLUSIONS

PCIs with rotational atherectomy guided by intravascular imaging modalities (IVUS or OCT) are associated with a higher procedural success rate compared to angio-guided procedures.

Intravascular Imaging-Guided Versus Coronary Angiography-Guided Complex PCI: A Meta-analysis of Randomized Controlled Trials

INTRODUCTION

Trials evaluating the role of intravascular imaging in percutaneous coronary intervention (PCI) for complex coronary artery disease have yielded mixed results. This study aimed to compare the outcomes of intravascular imaging specifically intravascular ultrasound (IVUS) with those from conventional coronary angiography in complex PCI.

METHODS

Comprehensive electronic search of MEDLINE, EMBASE, and Cochrane databases was performed until March 2023 for randomized clinical trials (RCTs) comparing intravascular imaging with coronary angiography in patients undergoing complex PCI. Complex PCI was defined per each study, and included PCI for American College of Cardiology/American Heart Association (ACC/AHA) type B2/C lesions, unprotected left main coronary artery disease, or multivessel stenting. The primary study outcome was major adverse clinical events (MACE).

RESULTS

The meta-analysis included 10 RCTs with a total of 6615 patients (3576 in the intravascular imaging group and 3039 in the coronary angiography group). The weighted mean-follow up was 28.9 months. Compared with coronary angiography, intravascular imaging reduced MACE (8% vs. 13.3%; relative risk [RR] 0.63; 95% confidence interval [CI] 0.54-0.73), cardiac death (RR 0.47; 95% CI 0.31-0.73), definite/probable stent thrombosis (RR 0.48; 95% CI 0.24-0.97), target vessel revascularization (RR 0.62; 95% CI 0.46-0.83), and target lesion revascularization (RR 0.61; 95% CI 0.47-0.79). There was no difference between both groups in all-cause death (RR 0.79; 95% CI 0.53-1.18) and myocardial infarction (RR 0.80; 95% CI 0.61-1.04).

CONCLUSION

In patients undergoing complex PCI, intravascular imaging-specifically IVUS-reduced MACE by decreasing the incidence of cardiac death, stent thrombosis, and target vessel and target lesion revascularization.

Feasibility of rotational atherectomy in patients with acute coronary syndrome: favorable in-hospital outcomes and clinical importance of complexed coronary atherosclerosis

The feasibility of rotational atherectomy (RA) during percutaneous coronary intervention (PCI) in patients who present with acute coronary syndrome (ACS) remains fully unsettled. We retrospectively evaluated 198 consecutive patients who underwent RA during PCI from 2009 to 2020. All patients underwent intracoronary imaging (intravascular ultrasound 96.5%, optical coherence tomography 9.1%, both 5.6%) during PCI. Patients who underwent RA during PCI were divided into two groups: ACS (n = 49; unstable angina pectoris, n = 27; non-ST-elevation myocardial infarction, n = 18, and ST-elevation myocardial infarction, n = 4) and chronic coronary syndrome (CCS) (n = 149). The RA procedural success rate was comparable between in the ACS and CCS groups (93.9 vs. 89.9%, P = 0.41). No significant differences were observed in procedural complications and in-hospital death between the groups. The incidence of major adverse cardiovascular event (MACE) after 2 years was significantly higher in ACS group compared with CCS group (38.7 vs. 17.4%, log-rank P = 0.002). Multivariable Cox regression analysis identified SYNTAX score or CABG SYNTAX score > 22 (hazard ratio (HR) 2.66, 95% confidence interval (CI) 1.40-5.06, P = 0.002) and mechanical circulatory support during the procedure (HR 2.61, 95% CI 1.21-5.59, P = 0.013) as predictors of MACE at 2 years, but not ACS on index admission (HR 1.58, 95% CI 0.84-2.99, P = 0.151). RA procedure is feasible as a bail-out strategy for ACS lesions. However, more complexed coronary atherosclerosis and mechanical circulatory support during RA procedure, but no ACS lesions were associated with worse mid-term clinical outcomes.

The Role of Intracoronary Imaging for the Management of Calcified Lesions

Interventional cardiologists in everyday practice are often confronted with calcified coronary lesions indicated for percutaneous transluminal coronary angioplasty (PTCA). PTCA of calcified lesions is associated with diverse technical challenges resulting in suboptimal coronary stenting and adverse long-term clinical outcomes. Angiography itself offers limited information regarding coronary calcification, and the adjuvant use of intracoronary imaging such as intravascular ultrasound (IVUS) and Optical Coherence Tomography (OCT) can guide the treatment of calcified coronary lesions, optimizing the different stages of the procedure. This review offers a description of why, when, and how to use intracoronary imaging for PTCA of calcified coronary lesions in order to obtain the most favorable results. We used the PubMed and Google Scholar databases to search for relevant articles. Keywords were calcified coronary lesions, intracoronary imaging, IVUS, OCT, coronary calcium modification techniques, PTCA, and artificial intelligence in intracoronary imaging. A total of 192 articles were identified. Ninety-one were excluded because of repetitive or non-important information.

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.

Intravascular Ultrasound and Optical Coherent Tomography Combined Catheter

Intravascular ultrasound (IVUS) and optical coherence tomography (OCT) are established intravascular imaging tools for evaluating plaque characteristics and volume, together with guiding percutaneous coronary interventions. The high tissue penetration of IVUS facilitates assessment of the entire vessel wall, whereas the higher resolution of OCT allows detailed assessment of endoluminal structures. A combined IVUS-OCT probe works synergistically, facilitating a greater understanding of de novo coronary artery disease and a better correlation with pathological specimens. In this review, we discuss the rationale and potential roles of the combined IVUS-OCT catheter system.

Intravascular Ultrasound-Guided Percutaneous Coronary Intervention: Practical Application

Why is intravascular ultrasounography (IVUS) highly encouraged for the practical guidance of percutaneous coronary intervention (PCI)? First reason is to understand the mechanism of revascularization. Even if stenoses look similar in angiography, the pathophysiology could be different in each lesion. Second reason is to anticipate possible complications in advance. With prediction and appropriate preparation, most complications can be avoided or managed calmly when they occur. Third reason is to optimize PCI results with interactive IVUS use during the procedure. All these are essential to maximize the results of revascularization while minimizing acute complications, ultimately leading to improved long-term clinical outcomes.

Current clinical use of intravascular ultrasound imaging to guide percutaneous coronary interventions (update)

There are 3 main reasons to promote the practical application of IVUS during PCI. First reason is to understand the mechanism of vessel dilatation. Even if angiographic stenoses are similar, their pathophysiologies are different. It is important to understand what can happen by dilating coronary artery with balloon/stent, and to develop a strategy to achieve the maximum effect. Second reason is to anticipate possible complications and to reduce them in advance. In that case, we can deal with it as calmly as possible. Third reason is to validate the PCI performed. This should lead to further improvements of the procedures, which in turn will lead to improved short- and long-term prognosis. Then, high-quality PCI could be possible. This review summarizes the standard usage of IVUS in routine clinical practice and the use of IVUS in specific situations, especially complex lesions.

Comparison of Two Different Rota-Flush Solutions in Patients Undergoing Rotational Atherectomy: A Randomized, Controlled, Triple-Blind Trial

INTRODUCTION

This prospective study accessed the feasibility and safety of the heparin rota-flush solution in patients undergoing rotational atherectomy (RA).

METHODS

Between August 2019 and November 2021, 200 patients who underwent RA were included in this study, among whom 103 (51.5%) were randomly allocated into the heparin rota-flush group and 97 (48.5%) into the traditional rota-flush group. The primary endpoint was the incidence of slow flow/no-reflow after RA; the secondary endpoints were procedural success, RA-related procedural complications, and in-hospital major adverse cardiovascular events (MACE).

RESULTS

There were no significant differences in baseline clinical and angiographic characteristics between the two groups. Thirty patients (29.1%) in the heparin rota-flush group and nineteen patients (19.6%) in the traditional rota-flush groups developed slow flow/no-reflow (P = 0.117), respectively, and procedural success was also comparable (97.1% vs. 93.8%, P = 0.320). Severe hypotension (systolic blood pressure < 90 mmHg) was not significantly different (15.5% vs. 16.5%, P = 0.841), but the incidence of coronary spasm was significantly higher in the heparin rota-flush group (42.7% vs. 22.7%, P = 0.003). MACE including stent-thrombosis (ST), target-lesion revascularization (TLR), and cardiac death were also comparable between the two groups; no stroke was observed.

CONCLUSIONS

The findings suggest that although continuous intracoronary infusion of heparin rota-flush solution does not increase the incidence of slow flow/no-reflow, traditional rota-flush solution without RotaGlide prevents coronary spasm more effectively compared to the heparin rota-flush without significant impact on severe hypotension. These results do not support a strategy of routine use of heparin rota-flush solution in patients receiving RA procedures.

Safety and Feasibility of Rotational Atherectomy for Retrograde Recanalization of Chronically Occluded Coronary Arteries

Objective

To evaluate the safety and feasibility of rotational atherectomy (RA) in retrograde chronic total occlusion percutaneous coronary intervention (CTO-PCI) by analyzing immediate and long-term outcomes.

Background

Recent evidence supports the safety and feasibility of RA in CTO-PCI. However, few studies have focused on the use of RA in a retrograde approach to percutaneous revascularization of chronic total occlusion (CTO) lesions and information on long-term outcomes is lacking.

Methods

A total of 329 patients who underwent retrograde CTO-PCI, out of 1496 consecutive CTO-PCI patients from April 2017 to July 2020, were retrospectively recruited from the 2nd Cardiology Department of the Guangdong Provincial People's Hospital. 16 patients underwent RA (RA group) whilst 313 did not (non-RA group).

Results

Technical (87.5% vs. 87.5) and procedural (85.9% vs. 87.5) success rates were similar between both groups. There was no difference concerning major procedural complications between groups (12.5% vs. 19.2%; p &gt; 0.75). No in-hospital MACCEs was recorded in the RA group while there were eight MACCEs in the non-RA group (p &gt; 0.99). In the RA group, 2 cases recorded perforation (1 target vessel perforation case and 1 branch vessel perforation), and 55 cases of vessel perforations/dissections were recorded in non-RA group including 18 target vessel perforations, 2 branch vessel perforations, 35 collateral vessel perforations (one patient died from cardiac tamponade). No difference was found in terms of the perforation rate between the two groups (p &gt; 0.99). Over a mean follow-up period of 26.47 ± 14.46 months, use of RA in retrograde CTO-PCI did not result in an increased mortality rate [hazard ratio (HR) 1.58, 95% confidence interval (CI), 0.31–8.21, p = 0.65], major adverse cardiac and cerebral events (HR 0.99, 95% CI 0.35–2.79, p = 0.99) or overall rehospitalization rate (HR 1.27, 95% CI 0.44–3.67, p = 0.67). Adjusted Kaplan–Meier curves according to Cox regression model suggested several predictors influencing the all-cause mortality, cardiovascular mortality, MACCEs, stroke rate, non-fatal myocardial infarction, target vessel recanalization rate and rehospitalization rate in the comparison.

Conclusions

Our study demonstrates that the in-hospital outcomes and long-term follow up events were the same between RA and non-RA retrograde CTO-PCI patients. RA offered an option for skillful operators in difficult cases when the lesion was severely calcified in retrograde CTO-PCI.

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.

The Impact of Intracoronary Imaging on PCI Outcomes in Cases Utilising Rotational Atherectomy: An Analysis of 8,417 Rotational Atherectomy Cases from the British Cardiovascular Intervention Society Database

Introduction

There is increasing evidence supporting the use of intracoronary imaging to optimize the outcomes of percutaneous coronary intervention (PCI). However, there are no studies examining the impact of imaging on PCI outcomes in cases utilising rotational atherectomy (RA-PCI). Our study examines the determinants and outcomes of using intracoronary imaging in RA-PCI cases including 12-month mortality.

Methods

Using the British Cardiac Intervention Society database, data were analysed on all RA-PCI procedures in the UK between 2007 and 2014. Descriptive statistics and multivariate logistic regressions were used to examine baseline, procedural, and outcome associations with intravascular imaging.

Results

Intracoronary imaging was used in 1,279 out of 8,417 RA-PCI cases (15.2%). Baseline covariates associated with significantly more imaging use were number of stents used, smoking history, previous CABG, pressure wire use, proximal LAD disease, laser use, glycoprotein inhibitor use, cutting balloons, number of restenosis attempted, off-site surgery, and unprotected left main stem (uLMS) PCI. Adjusted rates of in-hospital major adverse cardiac/cerebrovascular events (IH-MACCE), its individual components (death, peri-procedural MI, stroke, and major bleed), or 12-month mortality were not significantly altered by the use of imaging in RA-PCI. However, subgroup analysis demonstrated a signal towards reduction in 12-month mortality in uLMS RA-PCI cases utilising intracoronary imaging (OR 0.67, 95% CI 0.44–1.03).

Conclusions

Intracoronary imaging use during RA-PCI is associated with higher risk of baseline and procedural characteristics. There were no differences observed in IH-MACCE or 12-month mortality with intracoronary imaging in RA-PCI.

Impact of the degree of wire bias in the vessel's healthy portion on coronary perivascular trauma in rotational atherectomy

BACKGROUND

In rotational atherectomy (RA), the risk of coronary perforation is considered to increase when the wire is in contact with the healthy portion of the vessel. However, the relationship between the extent of wire bias in the healthy portion of the vessel and the risk of coronary perivascular trauma (CPT) has not been reported.

METHODS

We examined 90 consecutive cases wherein intravascular ultrasound (IVUS) was performed before and after RA. The IVUS catheter in contact with the healthy region of the vessel was defined as the healthy portion wire bias (HWB), of which we measured the bias diameter, defined as the media-to-media length between the site where the IVUS catheter was in contact and the opposite side of the vessel. The bias ratio was defined as the ratio of the bias diameter to the short diameter at the region where the wire bias was the strongest. The relationship between the bias ratio and the CPT risk was evaluated.

RESULTS

CPT was significantly higher in the HWB group than in the non-HWB group (9% vs. 0%, P = 0.048). In the HWB group, the bias ratio was significantly greater in the CPT group than in the non-CPT group (1.31 ± 0.09 vs. 1.06 ± 0.06; P < 0.0001). The cutoff value of the bias ratio for CPT was 1.2, which was the maximum value of the sum of sensitivity 100% and specificity 97%.

CONCLUSIONS

Lesions without HWB had no CPT. CPT risk increased when the bias ratio exceeded 1.2.

Successful off-label use of rotational atherectomy in ST-segment elevation myocardial infarction: A case report

Rotational atherectomy (RA) in ST-segment elevation myocardial infarction (STEMI) is uncommon and its use in a thrombotic lesion is labelled a contraindication by its manufacturer due to the concern for further increase in platelet activation and aggregation by the spinning burr or distal embolization of the thrombotic material promoting no-reflow (NR). However, thrombus burden varies significantly in the STEMI setting and can be classified according to the thrombolysis in myocardial infarction (TIMI) thrombus grade (TG). This case demonstrates the successful off-label use of RA-assisted primary percutaneous coronary intervention to facilitate treatment of a heavily calcified ostial right coronary artery lesion with low thrombotic burden (TIMI TG 0) in an octogenarian STEMI patient. Atherectomy drug cocktails, intracoronary vasodilators, short burr runs and avoidance of rotating the burr at slower than minimum approved rotational speed contribute to atherectomy success and decrease the chances of NR.

A prospective randomized feasibility trial comparing angiography and angiography with intravascular ultrasound for treatment of hemodialysis access failures

OBJECTIVE

Hemodialysis accesses suffer from limited primary patency requiring frequent interventions, revisions, or even abandonment. Prolongation of access life and usability with minimization of these adverse events is paramount. Endovascular methods are established first-line interventions for failing arteriovenous access and treatment of venous outflow stenoses. The Primary goal of this feasibility study was to evaluate intravascular ultrasound (IVUS) during interventional treatments on outcomes in those undergoing angiography for failing hemodialysis access. Secondary goals were to determine differences between IVUS and angiography on vessel and lesion characteristics and impact on treatment.

METHODS

In this prospective, randomized controlled trial, patients scheduled for angiography to evaluate and treat a failing hemodialysis access were randomized to use of angiography (DSA) alone or angiography plus IVUS (DSA + IVUS). Patients were treated by a standardized protocol and seen in follow-up at 2 weeks, and every 3 months for 2 years or until a study endpoint was reached. Measurement of vessel diameters, % stenosis, lesion length, and study endpoints (AV access thrombosis, re-intervention, or surgical revision) were recorded.

RESULTS

A total of 55 subjects were enrolled, 27 in the DSA cohort and 28 in the DSA + IVUS cohort. There were 41 treated lesions in each group. Freedom from the composite endpoint of AV access thrombosis or re-intervention was 46.3% in the DSA cohort and 61.0% in the DSA + IVUS cohort (p = 0.27). Diameter measurements matched between the two imaging modalities only 9 times out of 41 total comparison measures. In pre-treatment lesions with >80% stenosis, IVUS had a greater tendency than DSA to underestimate the severity of stenosis, whereas in pre-treatment lesions with 50-80% stenosis, DSA was more likely than IVUS to underestimate the severity of stenosis. Post-treatment % stenosis had mean difference of -7.5% between DSA versus DSA + IVUS cohorts. In five lesions with <30% stenosis measured by angiogram, IVUS led to treatment escalation.

CONCLUSION

In the interventional treatment of failing angioaccess, IVUS and angiography differ in the vast majority of cases in measurement of vessel diameter. A significant number of patients were found to have suboptimal therapeutic response by IVUS only, which led to an escalation in treatment, and in over one-third of cases, the IVUS results led to a change in treatment plan. The improved patency rates in the IVUS group was not statistically significant in this small population but should be further investigated in a larger trial.

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.

Procedural Characteristics and Outcomes of Patients Undergoing Percutaneous Coronary Intervention During Normal Work Hours Versus Non-work Hours

Percutaneous coronary intervention (PCI) performed during non-work hours is believed to have inferior outcomes because of operator fatigue, differences in baseline patient characteristics, and fewer on-call catheterization laboratory staff. We aimed to analyze a cohort of patients who underwent PCI (all comers) at our tertiary-care center between January 1, 2006, and December 31, 2018, and compare procedural and in-hospital outcomes between 2 groups defined by whether PCI was performed during normal work hours (7:00 A.M. to 7:00 PM) versus non-work hours (7:01 P.M. to 6:59 A.M. weekdays; all hours weekends and holidays). Finally, we examined temporal changes throughout the 24-hour weekday. Primary outcomes were unadjusted in-hospital adverse outcomes (composite death, recurrent myocardial infarction, emergent coronary artery bypass grafting, and target lesion revascularization). We identified 21,848 patients who underwent PCI at our institution. The proportions of ST-elevation myocardial infarction (STEMI) and non-ST-elevation myocardial infarction (NSTEMI) were higher during non-work hours. Overall, unadjusted in-hospital adverse outcomes were higher during non-work hours than during normal work hours (8.80% vs 2.00%; p <0.001). These findings were consistent based on the patient's clinical presentation (STEMI, NSTEMI, unstable angina, and stable angina). Despite confounding variables in the patients' presentations preventing definite causal attribution, our analysis demonstrates that in-hospital adverse outcomes were higher for those patients who underwent PCI (all comers) who had their procedures during non-work hours than during normal work hours.

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

Rotational atherectomy (RA) has been widely used for percutaneous coronary intervention (PCI) to severely calcified lesions. As compared to other countries, RA in Japan has uniquely developed with the aid of greater usage of intravascular imaging devices such as intravascular ultrasound (IVUS) or optical coherence tomography (OCT). IVUS has been used to understand the guidewire bias and to decide appropriate burr sizes during RA, whereas OCT can also provide the thickness of calcification. Owing to such abundant experiences, Japanese RA operators modified RA techniques and reported unique evidences regarding RA. The Task Force on Rotational Atherectomy of the J apanese Association of Cardiovascular Intervention and Therapeutics (CVIT) has now proposed the expert consensus document to summarize the contemporary techniques and evidences regarding RA.

Advances in IVUS/OCT and Future Clinical Perspective of Novel Hybrid Catheter System in Coronary Imaging

Intravascular ultrasound (IVUS) and optical coherence tomography (OCT) have been developed and improved as both diagnostic and guidance tools for interventional procedures over the past three decades. IVUS has a resolution of 100 μm with a high tissue penetration and capability of assessing the entire structure of a coronary artery including the external elastic membrane, whereas OCT has a higher resolution of 10–20 μm to assess endoluminal structures with a limited tissue penetration compared to IVUS. Recently, two companies, CONAVI and TERUMO, integrated IVUS and OCT into a single catheter system. With their inherent strength and limitations, the combined IVUS and OCT probes are complementary and work synergistically to enable a comprehensive depiction of coronary artery. In this review, we summarize the performance of the two intracoronary imaging modalities—IVUS and OCT—and discuss the expected potential of the novel hybrid IVUS–OCT catheter system in the clinical field.

Comparison of the incidence of slow flow after rotational atherectomy with IVUS-crossable versus IVUS-uncrossable calcified lesions

Although the usefulness of intravascular ultrasound (IVUS) in rotational atherectomy (RA) has been widely recognized, an IVUS catheter may not cross the target lesion because of severe calcification. The aim of this study was to compare the incidence of slow flow following RA between IVUS-crossable versus IVUS-uncrossable calcified lesions. We included 284 RA lesions, and divided into an IVUS-crossable group (n = 150) and an IVUS-uncrossable group (n = 134). The primary endpoint was slow flow just after RA. The incidence of slow flow (TIMI flow grade ≤ 2) was significantly greater in the IVUS-uncrossable group than in the IVUS-crossable group (26.1% vs. 10.7%, p = 0.001). The incidence of severe slow flow (TIMI grade ≤ 1) was also greater in the IVUS-uncrossable group than in the IVUS-crossable group (9.7% vs. 2.7%, p = 0.022). The multivariate logistic regression model showed a significant association between slow flow and pre-IVUS uncrossed lesions (vs. crossed lesions: odds ratio 2.103, 95% confidence interval 1.047–4.225, p = 0.037). In conclusion, the incidence of slow flow/severe slow flow just after RA was significantly greater in the IVUS-uncrossable lesions than in the IVUS-crossable lesions. Our study suggests the possibility that the IVUS-crossability can be used as a risk stratification of severe calcified lesions.

Contemporary Approach to Heavily Calcified Coronary Lesions

Percutaneous treatment of heavily calcified coronary lesions still represents a challenge for interventional cardiology, with higher risk of immediate complications, late failure due to stent underexpansion and malapposition, and consequently poor clinical outcome. Good characterisation of calcium distribution with multimodal imaging is important to improve the successful treatment of these lesions. The use of traditional or new dedicated devices for the treatment of calcified lesions allows better lesion preparation; therefore, it is important that we know the different mechanisms and technical features of these devices.

Comparison of complications with a 1.25-mm versus a 1.5-mm burr for severely calcified lesions that could not be crossed by an intravascular ultrasound catheter

Since intravascular imaging such as intravascular ultrasound (IVUS) can provide useful information for rotational atherectomy (RA), intravascular imaging should be attempted before RA. However, some calcified lesions do not allow imaging catheters to cross before RA. Although small burrs (1.25 mm or 1.5 mm) should be selected for such tight lesions, it is unknown whether a 1.25-mm burr or 1.5-mm burr is safer as the initial burr. The aim of this study was to compare the incidence of complications with a 1.25-mm versus a 1.5-mm burr as the initial burr for IVUS-uncrossable lesions. This was a retrospective, single-center study. A total of 109 IVUS-uncrossable lesions were included, and were divided into a 1.25-mm group (n =52) and a 1.5-mm group (n =57). The incidence of slow flow just after RA was not different between the 2 groups (1.25-mm group: 25%, 1.5-mm group: 31.6%, P =0.45). The incidence of peri-procedural MI with slow flow was not different and equally low in the 2 groups (1.25-mm group: 1.9%, 1.5-mm group: 3.5%, P =0.61). The use of the 1.5-mm burr as the initial burr was not significantly associated with slow flow after controlling for chronic renal failure on hemodialysis and reference diameter (vs. 1.25-mm: OR 2.34, 95% CI 0.89-6.19, P =0.09). In conclusion, the incidence of complications following RA was comparable between the 1.25-mm and the 1.5-mm burrs as the initial burr for IVUS-uncrossable lesions. The present study provides insights into the selection of an appropriate burr for IVUS-uncrossable lesions.

Halfway rotational atherectomy for calcified lesions: Comparison with conventional rotational atherectomy in a propensity-score matched analysis

Background

The incidence of severe complications such as burr entrapment or perforation is considerable with rotational atherectomy (RA). Halfway RA is a novel strategy, in which an operator does not advance the burr to the end of a continuous calcified lesion, and performs balloon dilatation to treat the remaining part of the calcified lesion. The purpose of this study was to compare complications after halfway and conventional RA.

Methods

We included 307 consecutive lesions that were divided into a conventional RA group (n = 244) and halfway RA group (n = 63). In analysis 1, the incidence of complications was compared between the conventional RA and halfway RA groups. Propensity-score matching was used to match the intentional halfway RA and conventional RA. In analysis 2, the incidence of complications was compared between the matched conventional RA and intentional halfway RA groups.

Results

Burr entrapment (0.4%) and major perforation (0.8%) were observed in the conventional RA group, whereas there was no burr entrapment or perforation in the halfway RA group. The success rate of halfway RA was 90.5%, which required switching from halfway RA to conventional RA. The incidences of slow flow and periprocedural myocardial infarction with slow flow were similar between the intentional halfway RA and matched conventional RA groups.

Conclusions

There was no burr entrapment or vessel perforation following halfway RA. The incidences of slow flow and periprocedural myocardial infarction were similar between the intentional halfway RA and the matched conventional RA, indicating the safety of halfway RA.

Association of Excessive Speed Reduction with Clinical Factors During Rotational Atherectomy

BACKGROUND

Although the manufacturer recommends that excessive speed reduction (>5000 rpm) be avoided during rotational atherectomy (RA) for safety, excessive speed reduction is sometimes observed in clinical practice. The purpose of the present study was to examine the factors associated with excessive speed reduction during RA.

METHODS

Lesions (n = 300) treated by RA were divided into 3 groups: a mild speed reduction group (≤5000 rpm) (n = 182), a moderate speed reduction group (>5000-≤10,000 rpm) (n = 97), and a severe speed reduction group (>10,000 rpm) (n = 21). Two multivariate logistic regression analyses was performed to investigate the factors associated with >5000 rpm speed reduction, and factors associated with >10,000 rpm speed reduction.

RESULTS

Multivariate logistic regression analysis revealed that an ostial right coronary artery (RCA) lesion (OR 6.13, 95% CI 1.82-20.70, P = 0.004) and total ablation time (every 10 s increase: OR 1.09, 95% CI 1.05-1.14, P < 0.001) were significantly associated with >5000 rpm speed reduction. An ostial RCA lesion (OR 14.17, 95% CI 3.85-52.23, P < 0.001), use of intra-aortic balloon pump support (OR 4.19, 95% CI 1.18-14.87, P = 0.03), and systolic blood pressure just before RA (every 10 mmHg increase: OR 1.25, 95% CI 1.02-1.52, P = 0.03) were significantly associated with >10,000 rpm speed reduction.

CONCLUSIONS

RA of ostial RCA lesions was significantly associated with excessive speed reduction during RA, which implies that RA of ostial RCA lesions is technically more difficult than RA of non-ostial RCA lesions.

Stentablation with Rotational Atherectomy for the Management of Underexpanded and Undilatable Coronary Stents

Stentablation with rotational atherectomy for the management of undilatable underexpanded coronary stents is a unique application associated with excellent periprocedural and in-hospital outcomes. Data regarding long-term outcomes remains limited, however the procedure appears to be associated with high prevalence of target lesion revascularization. Given the complexity of such lesions and few available interventional remedies; it is a reasonably safe and widely available approach of which operators should be aware. When stentablation is performed, the principles which guide contemporary rotational atherectomy and percutaneous coronary intervention, including intravascular imaging, should be applied.

Safety and Efficacy of Stentablation with Rotational Atherectomy for the Management of Underexpanded and Undilatable Coronary Stents

INTRODUCTION

Coronary stent underexpansion is associated with in-stent restenosis and few interventions are available for the management of undilatable underexpanded stents. Stentablation (SA) with rotational atherectomy (RA) is a unique application and has previously been described with encouraging results. Data regarding SA is limited to case reports and small case series; therefore, reasonable concern persists regarding procedural safety and long-term outcomes.

METHODS

This is a single-center retrospective study analyzing twenty consecutive patients who underwent SA with RA. The primary endpoint was procedural success and secondary endpoints included procedural safety outcomes and major adverse cardiac events (MACE) over a 12-month follow-up period.

RESULTS

Stentablation and secondary stenting were guided by intravascular ultrasound and procedural success was achieved in all cases. No in-hospital death or MACE was observed. The prevalence of MACE was 5% at 30 days as one patient developed recurrent MI without target lesion revascularization (TLR). At 12 months, MACE had occurred in 40% of patients, however this was strongly driven by a high prevalence of TLR (30%). Only one cardiac death (5%) and one additional NSTEMI were observed during the 11 additional months of follow up.

CONCLUSION

Stentablation with RA is a feasible and effective option for the acute management of symptomatic, underexpanded, and undilatable coronary stents. SA is associated with a high rate of procedural success as well as excellent in-hospital and short-term outcomes. However, our study population demonstrated substantial MACE at 12 months which was strongly driven by TLR and associated with minimal mortality.