Serial Morphological and Functional Assessment of Drug-Eluting Balloon for In-Stent Restenotic Lesions

Drug-coated balloons versus drug-eluting stents in patients with in-stent restenosis: An updated meta-analysis with trial sequential analysis

BACKGROUND

Drug-coated balloons (DCB) have promising results in the management of in-stent restenosis (ISR), still their role remains a major challenge, and not well established in contemporary clinical practice.

AIMS

To provide a comprehensive appraisal of the efficacy and safety of DCBs in patients with in-stent restenosis (ISR).

METHODS

We searched PubMed, Scopus, web of Science, Ovid, and Cochrane Central from inception until 30 March, 2023. We included randomized controlled trials (RCTs) that compared DCB versus DES in ISR patients. Our primary endpoints were major adverse cardiac events (MACE) and late lumen loss (LLL). Secondary clinical endpoints were all-cause death, cardiac death, MI, TLR, TVR, and stent thrombosis, and angiographic outcomes were MLD, and in-stent binary restenosis.

RESULTS

Ten RCTs comprising 1977 patients were included in this meta-analysis. The incidence of MACE was 15.57% in the DCB group compared to 14.13% in the DES group, with no significant difference in the risk of MACE following DCB (odds ratio [OR] 1.04, 95% confidence interval [CI]: 0.87 to 1.44). Compared with the DES intervention, the risk of LLL was comparable to the DCB intervention (mean difference [MD] -0.08, 95% CI: -0.18 to 0.02), while the incidence of TLR was increased in the DCB intervention (OR: 1.54, 95% CI: 1.2 to 1.99).

CONCLUSION

DCB was comparable to DES implantation is ISR patients regarding clinical outcomes, however it showed an increase in TLR events. Moreover, a RCT with large sample size and longer follow-up duration is warrened to validate these results.

Emerging Hybrid Intracoronary Imaging Technologies and Their Applications in Clinical Practice and Research

Intravascular ultrasound and optical coherence tomography are used with increasing frequency for the care of coronary patients and in research studies. These imaging tools can identify culprit lesions in acute coronary syndromes, assess coronary stenosis severity, guide percutaneous coronary intervention (PCI), and detect vulnerable plaques and patients. However, they have significant limitations that have stimulated the development of multimodality intracoronary imaging catheters, which provide improvements in assessing vessel wall pathology and guiding PCI. Prototypes combining 2 or even 3 imaging probes with complementary attributes have been developed, and several multimodality systems have already been used in patients, with near-infrared spectroscopy intravascular ultrasound-based studies showing promising results for the identification of high-risk plaques. Moreover, postmortem histology studies have documented that hybrid imaging catheters can enable more accurate characterization of plaque morphology than standalone imaging. This review describes the evolution in the field of hybrid intracoronary imaging; presents the available multimodality catheters; and discusses their potential role in PCI guidance, vulnerable plaque detection, and the assessment of endovascular devices and emerging pharmacotherapies targeting atherosclerosis.

Coronary Drug-Coated Balloons for De Novo and In-Stent Restenosis Indications

Drug-coated balloons are approved outside the United States, not only for the treatment of peripheral arteries but also for coronary arteries. This review describes the technological basics, the scenarios of clinical application, and the current available data from clinical trials for the different coronary indications.

Vascular healing responses to paclitaxel coated balloons or everolimus eluting stents for the treatment of in-stent restenosis. Insights from optical coherence tomography

BACKGROUND

Treatment of in-stent restenosis (ISR) remains a significant challenge. Current options include repeat stenting or drug-coated balloons. However, there is a paucity of data regarding vascular healing after these strategies. We, aimed to compare optical coherence tomography (OCT)-based vessel healing after treatment with paclitaxel-coated balloons (PCB) or everolimus-eluting stents (EES).

METHODS

An OCT substudy (baseline and 6-9 months) of patients from RIBS IV and RIBS V, two prospective multicenter, randomized controlled clinical trials comparing PCB vs. EES in patients with ISR was performed.

RESULTS

Sixty-four patients were included (30 PCB and 34 EES). There were no differences in the baseline or angiographic characteristics between groups. Both groups had the same proportion of drug-eluting and bare-metal stent (BMS) ISR. Baseline OCT analysis did not show differences in the qualitative characteristics of the ISR nor the restenotic tissue burden. Follow-up OCT showed a larger mean lumen area in the EES group (6.03 ± 1.5 vs. 5.24 ± 1.3 mm2; P = 0.043) but no difference in angiographic restenosis (P = 0.66). Percentage tissue coverage was higher with PCB vs. EES (26 ± 13 vs. 19 ± 11%; P = 0.031). EES-treated ISR more frequently had uncovered struts at follow-up [21 (72%) vs. 12 (44%); P = 0.034]. Tissue covering struts more frequently had a high backscatter structure after PCB [21 (78%) vs. 16 (55%); P = 0.07].

CONCLUSIONS

Compared with EES, ISR treated with PCB demonstrated more strut coverage with mainly high backscattering tissue. Larger OCT-defined neointimal proliferation in PCB-treated ISR did not translate into higher angiographic restenosis rates.

Long-term outcomes after deferral of revascularization of in-stent restenosis using fractional flow reserve

OBJECTIVES

To investigate the outcomes of deferred coronary revascularization in patients with non-significant in-stent restenosis (ISR) by physiological assessment.

BACKGROUND

The pathophysiology and natural history of ISR is markedly different from de-novo stenoses. There is a paucity of data on the safety of deferral of revascularization of ISR using physiological assessment.

METHODS

In this single centre study, using a propensity-score matched analysis, we compared the long-term clinical outcomes of patients with ISR and de-novo disease deferred based on intracoronary physiology. Matching was on a 1:2 basis of ISR to de-novo stenosis. The primary end point was major adverse cardiovascular events (MACE) a composite of all-cause mortality, target lesion revascularization or target vessel myocardial infarction at 36 months.

RESULTS

Matched cohorts of 56 ISR and 112 de-novo stenoses were analyzed. The median percentage stenosis was 50% in both groups (p = 0.403). Deferral was based on fractional flow reserve (FFR). The mean FFR was 0.86 across both groups (p = 0.942). At 36-months, freedom from MACE was similar between groups; 86.2% versus 92.8% log rank p=0.180 for ISR and de-novo lesions, respectively. Neither were there differences in the individual components of MACE.

CONCLUSIONS

Deferral of coronary revascularization in patients with ISR based on its functional impact is associated to similar long-term safety as in de-novo coronary stenosis.

Angiography and Optical Coherence Tomography Assessment of the Drug-Coated Balloon ESSENTIAL for the Treatment of In-Stent Restenosis

OBJECTIVES

This study sought to assess the efficacy of the drug-coated balloon (DCB) ESSENTIAL for the treatment of in-stent restenosis (ISR).

BACKGROUND

DCBs have proven a valid therapeutic option for the management of ISR in several clinical trials, yet no class effect can be claimed. Accordingly, every new DCB model has to be individually evaluated through clinical studies.

METHODS

This is a prospective, multicenter study including consecutive patients undergoing percutaneous coronary intervention for ISR with the ESSENTIAL DCB. A 6-month quantitative coronary angiography (QCA)/optical coherence tomography (OCT) follow-up was scheduled. The primary endpoint was OCT-derived in-segment maximal area stenosis. Secondary endpoints included QCA-derived in-segment late lumen loss (LLL) and target lesion failure (TLF) rates at 6, 12, and 24 months. TLF was defined as the composite of cardiac death, target vessel myocardial infarction, and target lesion revascularization.

RESULTS

A total of 31 patients were successfully treated with DCB, with 67% of ISR corresponding to drug-eluting stents (DES). At 6 months, 26 patients underwent the scheduled angiographic follow-up. The mean value for in-segment maximal area stenosis was 51.4 ± 13% and the median value was 53% (IQR 46.4-59.5). In the DES-ISR subgroup, these parameters were 52.6 ± 10% and 55.2% (IQR 49.3-58.5), respectively. In-segment LLL was 0.25 ± 0.43 mm with only 2 (7.7%) patients showing binary restenosis (>50%). The incidence of TLF was 10% at 6 months, 13.3% at 12 months, and 13.3% at 24 months.

CONCLUSIONS

In this study, the ESSENTIAL DCB showed sustained efficacy in the prevention of recurrent restenosis after treatment of ISR.

SUMMARY

We sought to assess the efficacy of the drug-coated balloon ESSENTIAL for the treatment of in-stent restenosis through a prospective, multicenter study including QCA and OCT assessment at 6-month follow-up. The primary endpoint was in-segment maximal area stenosis. Among the 31 patients successfully treated with the ESSENTIAL DCB, an angiographic follow-up was conducted in 26. Mean in-segment maximal area stenosis was 51.4 ± 13% and the median value was 53% (IQR 46.4-59.5). In the DES-ISR subgroup, corresponding values were 52.6 ± 10% and 55.2% (IQR 49.3-58.5), respectively. The observed in-segment LLL was 0.25 ± 0.43 mm and binary restenosis rate was 7.7%. TLF was 10% at 6 months and 13.3% at 12 and 24 months.

Treatment of In-Stent Restenosis by Excimer Laser Coronary Atherectomy and Drug-Coated Balloon: Serial Assessment with Optical Coherence Tomography

Objectives

We aimed to compare the results of neointimal modification before drug-coated balloon (DCB) treatment with excimer laser coronary atherectomy (ELCA) plus scoring balloon predilation versus scoring balloon alone in patients presenting with in-stent restenosis (ISR).

Background

Treatment of ISR with ELCA typically results in superior acute gain by neointima debulking. However, the efficacy of combination therapy of ELCA and DCB remains unknown.

Methods

A total of 42 patients (44 ISR lesions) undergoing DCB treatment with ELCA plus scoring balloon (ELCA group, n = 18) or scoring balloon alone (non-ELCA group, n = 24) were evaluated via serial assessment by optical coherence tomography (OCT) performed before, after intervention, and at 6 months.

Results

Although there was significantly greater frequency of diffuse restenosis and percent diameter stenosis (%DS) after intervention in the ELCA group, comparable result was shown in %DS, late lumen loss, and binary angiographic restenosis at follow-up. On OCT analysis, a decreased tendency in the minimum lumen area and a significant decrease in the minimum stent area were observed in the ELCA group between 6-month follow-up and after intervention (-0.89 ± 1.36 mm² vs. -0.09 ± 1.25 mm², p = 0.05, -0.49 ± 1.48 mm² vs. 0.28 ± 0.78 mm², p = 0.03, respectively). The changes in the neointimal area were similar between the groups, and target lesion revascularization showed comparable rates at 1 year (11.1% vs. 11.4%, p = 0.85).

Conclusions

Despite greater %DS after intervention, ELCA before DCB had possible benefit for late angiographic and clinical outcome.

Positive Vessel Remodelling

Since its introduction, the success of percutaneous transluminal coronary angioplasty (PTCA) has been jeopardised by recoil, neointima proliferation, and luminal renarrowing; however, the benefit of positive remodelling has not gained widespread attention. While vessels will remodel positively up to a certain stage in the development of atherosclerosis, the therapeutic application of this process remains low. The prevention of vessel shrinkage during the healing process, which represents the predominant mechanism of restenosis after PTCA, is a prerequisite of long-term success in PTCA. The antiproliferative drugs that are currently used mainly on stents are known to be capable of this. Primary clinical studies have reported that positive remodelling leads to beneficial effects in coronary and peripheral angioplasty if no foreign body is inserted, and a paradigm change in percutaneous coronary intervention towards far fewer implants is within reach.

Clinical outcomes in patients treated for coronary in-stent restenosis with drug-eluting balloons: Impact of high platelet reactivity

BACKGROUND

The impact of high platelet reactivity (HPR) on clinical outcomes after elective percutaneous coronary interventions (PCI) with drug-eluting balloons (DEB) due to in-stent restenosis (ISR) is unknown.

OBJECTIVE

We sought to evaluate the prognostic importance of HPR together with conventional risk factors in patients treated with DEB.

METHODS

Patients treated with DEB due to ISR were enrolled in a single-centre, prospective registry between October 2009 and March 2015. Only patients with recent myocardial infarction (MI) received prasugrel, others were treated with clopidogrel. HPR was defined as an ADP-test >46U with the Multiplate assay and no adjustments were done based on results. The primary endpoint of the study was a composite of cardiovascular mortality, MI, any revascularization or stroke during one-year follow-up.

RESULTS

194 stable angina patients were recruited of whom 90% were treated with clopidogrel. Clinical characteristics and procedural data were available for all patients; while platelet function testing was performed in 152 subjects of whom 32 (21%) had HPR. Patients with HPR had a higher risk for the primary endpoint (HR: 2.45; CI: 1.01-5.92; p = 0.03). The difference was primarily driven by a higher risk for revascularization and MI. According to the multivariate analysis, HPR remained a significant, independent predictor of the primary endpoint (HR: 2.88; CI: 1.02-8.14; p = 0.04), while total DEB length and statin treatment were other independent correlates of the primary outcome.

CONCLUSION

HPR was found to be an independent predictor of repeat revascularization and MI among elective patients with ISR undergoing PCI with DEB.

Restenosis of the Coronary Arteries: Past, Present, Future Directions

Restenosis is a pathologic response to vascular injury, characterized by neointimal hyperplasia and progressive narrowing of a stented vessel segment. Although advances in stent design have led to a dramatic reduction in the incidence of restenosis, it continues to represent the most common cause of target lesion failure following percutaneous coronary intervention. Efforts to maximize restenosis prevention, through careful consideration of modifiable risk factors and an individualized approach, are critical, as restenosis, once established, can be particularly difficult to treat. Novel approaches are on the horizon that have the potential to alter the natural history of this stubborn disease.

Optical coherence tomography evaluation of intermediate-term healing of different stent types: systemic review and meta-analysis

AIMS

The intermediate-term incidence of strut malapposition (SM) and uncovered struts (US), and the degree of neointimal thickness (NIT) according to stent type have not been characterized.

METHODS AND RESULTS

All studies of >50 patients in which optical coherence tomography was performed between 6 and 12 months after stent implantation were included. The incidences of SM and US were the co-primary end points, while NIT was the secondary end point. A total of 458 citations were initially appraised at the abstract level, and 11 full-text studies (280 652 analysed struts, 921 patients) were assessed. The 6-12 months incidences of SM and US were 5.0 and 7.8%, respectively, and the mean NIT was 206 μm. Biolimus-eluting stents (BES) and bioresorbable vascular scaffolds (BVS) had the highest SM rates (2.7 and 3.8%, respectively), while everolimus-eluting stents (EES) and fast-release zotarolimus-eluting stents (ZES) had the lowest SM rates (0.9 and 0.1%, respectively). BES and sirolimus-eluting stents (SES) had the highest US rates (7.7 and 8.8%, respectively), while bare metal stents (BMS) and ZES had the lowest US rates (0.3 and 0.3%, respectively). BMS had the greatest NIT (340 μm), while SES, EES, and BES had the least NIT.

CONCLUSION

Second-generation drug-eluting stents (DES) have better intermediate-term strut apposition and coverage than first-generation DES, BVS, and BMS. EES demonstrate the overall best combination of healing with suppression of neointimal hyperplasia at 6-12 months. Further studies with clinical correlation are warranted to determine the implications of these findings.

Paclitaxel-coated balloon catheter compared with drug-eluting stent for drug-eluting stent restenosis in routine clinical practice

AIMS

The aim of this study was to compare the efficacy between paclitaxel-coated balloon (PCB) and drug-eluting stent (DES) implantation for the treatment of DES restenosis in complex situations.

METHODS AND RESULTS

Data of patients who received revascularisation for DES restenosis between 2004 and 2011 were collected. A total of 683 patients with 777 lesions were analysed in this study (306 lesions treated by PCB, 471 lesions by DES). The use of PCB or DES was at the discretion of the operator. Angiographic outcomes at six to eight months and clinical outcomes at 12-month follow-up were compared between groups. The primary outcome was binary restenosis. Cox regression analysis with propensity score adjustment suggested that there were no significant differences between the two groups with respect to binary restenosis, target lesion revascularisation (TLR), and major adverse cardiac events. As for the angiographic endpoints, subgroup analysis was performed for several parameters. There was a significant trend favouring PCB with respect to binary restenosis and TLR in non-focal type lesions and bifurcation lesions.

CONCLUSIONS

Angiographic and clinical outcomes in the PCB group were similar to those in the repeat DES group. PCB seemed to offer more favourable results in non-focal type lesions and bifurcation lesions.

Impact of Angiographic Result After Predilatation on Outcome After Drug-Coated Balloon Treatment of In-Stent Coronary Restenosis

This study investigates clinical outcomes after drug-coated balloon (DCB) treatment for in-stent restenosis (ISR) based on the angiographic result achieved after predilatation and before DCB treatment. Among ISR lesions treated with DCBs, 166 lesions with angiography immediately after predilatation were analyzed. The lesions were divided into 2 groups according to angiographic results after predilatation: (1) "adequate" defined as the presence of Thrombolysis In Myocardial Infarction 3 flow, residual stenosis ≤30%, and no major dissections (n = 98 lesions) or (2) "inadequate" (n = 68 lesions). The reference vessel diameters were larger (2.88 ± 0.39 vs 2.64 ± 0.52 mm, p = 0.001) and lesion lengths shorter in the adequate group (15.4 ± 11.2 vs 19.7 ± 13.9 mm, p = 0.04). During a median follow-up of 808 days, the cumulative target lesion revascularization (TLR) rate was lower in the adequate group (20.3% vs 35.5% at 2 years; p = 0.04). Multivariate analysis indicated that an angiographically inadequate result before DCB treatment was an independent predictor of TLR, even after adjusting for reference vessel diameter and lesion length (hazard ratio 1.99, 95% confidence interval 1.02 to 3.87, p = 0.04). In conclusion, angiographic results after lesion preparation appear to be a good predictor of TLR after DCB treatment for ISR.

Comparison of drug-eluting balloon versus drug-eluting stent treatment of drug-eluting stent in-stent restenosis: A meta-analysis of available evidence

BACKGROUND

In-stent restenosis (ISR) remains an important concern despite the recent advances in the drug-eluting stent (DES) technology. The introduction of drug-eluting balloons (DEB) offers a good solution to such problem.

OBJECTIVES

We performed a meta-analysis to assess the clinical efficiency and safety of DEB compared with DES in patients with DES-ISR.

METHODS

A systematic search was conducted and all randomized and observational studies which compared DEB with DES in patients with DES-ISR were included. The primary outcome measure-major adverse cardiovascular events (MACE)-as well as individual events as target lesion revascularization (TLR), stent thrombosis (ST), myocardial infarction (MI), cardiac death (CD) and all-cause mortality, were analyzed.

RESULTS

Three randomized and 4 observational studies were included with a total of 2052 patients. MACE (relative risk [RR]=1.00, 95% confidence interval (CI) 0.68 to 1.46, P=0.99), TLR (RR=1.15 [CI 0.79 to 1.68], P=0.44), ST (RR=0.37[0.10 to 1.34], P=0.13), MI (RR=0.97 [0.49 to 1.91], P=0.93) and CD (RR=0.73 [0.22 to 2.45], P=0.61) were not different between patients treated with DEB and with DES. However, all-cause mortality was lower in patients treated with DEB (RR=0.45 [0.23 to 0.87, P=0.019) and in particular when compared to only first generation DES (RR 0.33 [0.15-0.74], P=0.007). There was no statistical evidence for publication bias.

CONCLUSIONS

The results of this meta-analysis showed that DEB and DES have similar efficacy and safety for the treatment of DES-ISR.

Serial Morphological and Functional Assessment of the Paclitaxel-coated Balloon for de Novo Lesions

INTRODUCTION AND OBJECTIVES

There is limited data on the serial morphological and functional assessment of paclitaxel-coated balloon treatment using coronary angiography, optical coherence tomography, and fractional flow reserve.

METHODS

In this prospective, single-center observational study, patients with de novo lesions were treated with the paclitaxel-coated balloon. Serial angiographic, optical coherence tomography and fractional flow reserve measurements were performed before and after plain old balloon angioplasty, as well as at 9-month follow-up.

RESULTS

Twenty patients (21 lesions) were enrolled in this study. The reference vessel diameter was 2.68±0.34mm and late luminal loss was 0.01±0.21mm. The median changes in the minimal lumen area between pre- and postplain old balloon angioplasty, and postplain old balloon angioplasty and follow-up were an increase of 75.2% [interquartile range of 37.2 to 164.7] and 50.0% [interquartile range of 1.1% to 64.5%], respectively. Intimal dissections were seen in all postprocedural optical coherence tomography images, and 66.6% of them were sealed on follow-up optical coherence tomography (median 278 days). The fractional flow reserve distal to the target lesion was 0.71±0.14 predilatation, 0.87±0.04 postdilatation, and 0.83±0.08 at follow-up.

CONCLUSIONS

The paclitaxel-coated balloon restores coronary blood flow by means of plaque modification, causing an increment in minimal lumen area. At 9-month follow-up, coronary flow was sustained and the luminal patency was the result of suppressed luminal narrowing progression from local drug effects on the de novo coronary lesions.

Effect of Drug-Coated Balloons in Native Coronary Artery Disease Left With a Dissection

OBJECTIVES

The authors sought to understand the clinical and angiographic outcomes of dissections left after drug-coated balloon (DCB) angioplasty.

BACKGROUND

Second-generation DCB may be an alternative to stents in selected populations for the treatment of native coronary lesions. However, the use of these devices may be hampered by a certain risk of acute vessel recoil or residual coronary dissection. Moreover, stenting after DCB has shown limited efficacy. Little is known about when a non-flow-limiting dissection is left after DCB angioplasty.

METHODS

This was a prospective observational study whose aim was to investigate the outcome of a consecutive series of patients with native coronary artery disease treated with second-generation DCB and residual coronary dissection at 2 Italian centers. We evaluated patient clinical conditions at 1 and 9 months, and angiographic follow up was undertaken at 6 months.

RESULTS

Between July 2012 and July 2014, 156 patients were treated with DCB for native coronary artery disease. Fifty-two patients had a final dissection, 4 of which underwent prosthesis implantation and 48 were left untreated and underwent angiographic follow-up after 201 days (interquartile range: 161 to 250 days). The dissections were all type A to C, and none determined an impaired distal flow. Complete vessel healing at angiography was observed in 45 patients (93.8%), whereas 3 patients had persistent but uncomplicated dissections, and 3 had binary restenosis (6.2%). Late lumen loss was 0.14 mm (-0.14 to 0.42). Major adverse cardiovascular events occurred in 11 patients in the entire cohort and in 4 of the dissection cohort (7.2% vs. 8.1%; p = 0.48). We observed 8 and 3 target lesion revascularizations, respectively (5.3% vs. 6.2%; p = 0.37).

CONCLUSIONS

In this cohort of consecutive patients treated with new-generation DCB and left with a final dissection, this strategy of revascularization seemed associated with the sealing of most of dissections and without significant neointimal hyperplasia.

Comparative assessment of the antirestenotic efficacy of two paclitaxel drug-eluting balloons with different coatings in the treatment of in-stent restenosis

Background/objectives

Preclinical investigations have suggested that coating technology is crucial for the efficacy of drug-eluting balloons (DEB). Aim of this study is to compare the antirestenotic efficacy of two paclitaxel DEB with different coatings in the treatment of in-stent restenosis (ISR) by means of a morphological and functional assessment.

Methods

In a single center, prospective, non-randomized study, the shellac-paclitaxel coated DIOR, and the urea-paclitaxel coated IN.PACT Falcon were compared in the setting of ISR. Quantitative angiography, fractional flow reserve (FFR), and optical coherence tomography (OCT) were performed at baseline, postprocedure and 6-month follow-up. Main endpoints were QCA, FFR and OCT-based parameters of restenosis.

Results

Forty-five patients were included, 20 (44 %) received treatment with the DIOR and 25 (56 %) with the IN.PACT Falcon. Angiographic and device success were 100 and 90 % for the DIOR, and 100 and 92 % for the IN.PACT Falcon, respectively. After 6-months, in-segment late lumen loss (−0.03 ± 0.43 vs. 0.36 ± 0.48 mm, p = 0.014) and diameter stenosis (30.7 ± 16.2 vs. 41.3 ± 22.6 %, p = 0.083) were lower for the IN.PACT Falcon. FFR distal of the stent was significantly higher in the IN.PACT Falcon group (0.92 ± 0.07 vs. 0.84 ± 0.13, p = 0.029) and in-stent FFR gradient was lower (0.05 ± 0.05 vs. 0.13 ± 0.12, p = 0.002). Between postprocedure and follow-up, a 16 % decrease in neointimal volume was observed for the IN.PACT Falcon, while a 30 % increase was observed for the DIOR (p = 0.006).

Conclusions

The IN.PACT Falcon DEB showed higher antirestenotic efficacy than the DIOR in the treatment of ISR, demonstrating that DEB with an excipient-based coating is not equally effective.

Electronic supplementary material

The online version of this article (doi:10.1007/s00392-015-0934-0) contains supplementary material, which is available to authorized users.

Accuracy of intravascular ultrasound and optical coherence tomography in identifying functionally significant coronary stenosis according to vessel diameter: A meta-analysis of 2,581 patients and 2,807 lesions

INTRODUCTION

Accuracy of intracoronary imaging to discriminate functionally significant coronary stenosis according to vessel diameter remains to be defined.

METHODS

PubMed, Scopus, and Google Scholar were systematically searched for studies assessing diagnostic accuracy (area under the receiver operating characteristic curve [AUC], the primary end point) and sensitivity and specificity (the secondary end points) of minimal luminal area (MLA) or of minimal luminal diameter (MLD) derived from intravascular ultrasound (IVUS) or optical coherence tomography (OCT) to detect functionally significant stenosis as determined with fractional flow reserve (FFR).

RESULTS

Fifteen studies were included, 2 with 110 patients analyzing only left main (LM), 5 with 224 patients and 306 lesions using OCT, and 9 with 1532 patients and 1681 lesions with IVUS. Median MLA for the OCT studies was 1.96 mm(2) (1.85-1.98 mm(2)), 2.9 mm(2) (2.7-3.1 mm(2)) for MLA of all lesions assessed with IVUS, 2.8 mm(2) (2.7-2.9 mm(2)) for lesions with an angiographic diameter >3 mm, 2.4 mm(2) (2.4-2.5 mm(2)) for lesions <3 mm, and 5.4 mm(2) (5.1-5.6 mm(2)) for LM lesions. For OCT-MLA, AUC was 0.80 (0.74-0.86), with a sensitivity of 0.81 (0.74-0.87) and specificity of 0.77 (0.71-0.83), whereas OCT-MLD had an AUC of 0.85 (0.79-0.91), sensitivity of 0.74 (0.69-0.78), and specificity of 0.70 (0.68-0.73). For IVUS-MLA, AUC was 0.78 (0.75-0.81) for all lesions, 0.78 (0.73-0.84) for vessels with a diameter >3 mm, and 0.79 (0.70-0.89) for those with a diameter <3 mm. Left main AUC was 0.97 (0.93-1).

CONCLUSION

Intravascular ultrasound and OCT had modest diagnostic accuracy for identification hemodynamically significant lesions, also with specific cutoff for different diameters. Invasive imaging for assessment of LM severity demonstrated excellent correlation with FFR. What is already known about this subject? Fractional flow reserve represents the criterion standard to evaluate the prognostic value of coronary stenosis, whereas its relationship with IVUS and OCT remains to be assessed. What does this study add? Despite improvement, IVUS and OCT do not predict functional stenosis, even with dedicated cutoff, apart from LM disease. How might this impact on clinical practice? The recent guidelines of myocardial revascularization have stressed the crucial role of FFR before performing percutaneous coronary intervention on LM, whereas intravascular imaging is often exploited to drive revascularization. The present analysis stresses the point that LM percutaneous coronary intervention may be driven only by intravascular imaging, given the high accuracy for significant ischemic lesions, whereas for other vessels, these 2 techniques mirror 2 different aspects.

Meta-analysis of randomized trials comparing the effectiveness of different strategies for the treatment of drug-eluting stent restenosis

The investigators performed a network meta-analysis of randomized trials comparing the effectiveness of currently available strategies for the treatment of drug-eluting stent (DES) restenosis. Despite the widespread use of DES in patients who undergo percutaneous coronary intervention, the optimal treatment for DES restenosis remains poorly defined. A systematic search of electronic resources was performed. The primary end point was diameter stenosis at follow-up angiography. Seven trials were included, enrolling a total of 1,586 patients with 1,728 restenotic lesions. The following treatment options were found: balloon angioplasty (BA) in 343 patients (19.3%), iopromide-based paclitaxel-eluting balloons (PEB) in 343 (21.6%), sirolimus-eluting stents in 441 (27.8%), paclitaxel-eluting stents in 462 (29.1%), and everolimus-eluting stents in 34 (2.2%). Compared with BA, PEB (-17.74%, 95% credible interval [CI] -25.17% to -11.31%), everolimus-eluting stents (-14.93%, 95% CI -33.47% to 1.16%), paclitaxel-eluting stents (-15.3%, 95% CI -22.96% to -8.35%), and sirolimus-eluting stents (-11.08%, 95% CI -17.89% to -3.4%) had similar reductions in diameter stenosis at follow-up angiography. PEB (85%) and everolimus-eluting stents (68%) had the greatest probabilities for being the best treatment option. Furthermore, PEB were the best treatment in terms of late luminal loss (85%) and binary restenosis (85%). BA had the lowest efficacy with respect to all study end points. In conclusion, in patients with DES restenosis, repeat DES implantation and iopromide-based PEB are valid alternatives. However, PEB had greater angiographic efficacy and therefore should be considered the new benchmark comparator in the treatment of DES restenosis. The use of BA should be discouraged in patients with DES restenosis.

A prospective, multicenter, randomized trial of paclitaxel-coated balloon versus paclitaxel-eluting stent for the treatment of drug-eluting stent in-stent restenosis: results from the PEPCAD China ISR trial

OBJECTIVES

The intention of the PEPCAD China ISR (A Prospective, Multicenter, Randomized Trial of Paclitaxel-Coated versus Paclitaxel-Eluting Stent for the Treatment of Drug-Eluting Stent In-Stent Restenosis) was to demonstrate the efficacy of paclitaxel-coated balloon (PCB) angioplasty in a non-European patient population with coronary drug-eluting stent in-stent restenosis (DES-ISR).

BACKGROUND

The treatment of DES-ISR is still challenging with no established best strategy. Moreover, there is no study on the effect of PCB in the treatment of ISR in the Chinese population.

METHODS

PEPCAD China ISR was a 220-patient randomized (1:1), single-blind prospective multicenter trial conducted in China. Patients with coronary DES-ISR received either PCB (SeQuent Please, B. Braun Melsungen AG, Melsungen, Germany) or paclitaxel-eluting stent (Taxus Liberté, Boston Scientific, Natick, Massachusetts) treatment. The primary endpoint was in-segment late lumen loss at 9 months.

RESULTS

There were no significant baseline differences between both treatment groups in terms of patient, lesion, or procedural characteristics. At 9 months, in-segment late lumen loss in the PCB group was noninferior to that of the paclitaxel-eluting stent group (0.46 ± 0.51 mm vs. 0.55 ± 0.61 mm; difference: -0.06 mm with 95% confidence interval: -0.23 to 0.10; p for noninferiority = 0.0005). The 9-month rate of binary restenosis and 12-month composite clinical event rates were not significantly different between groups.

CONCLUSIONS

In a randomized trial of 220 patients, angioplasty with a PCB was noninferior to paclitaxel-eluting stent implantation when used to treat DES-ISR. On the basis of these, as well as previous randomized trial data, PCB angioplasty offers an effective treatment for DES-ISR without the necessity of implanting additional metal layers for drug release. (A Safety and Efficacy Study of Paclitaxel-Eluting Balloon to Paclitaxel-Eluting Stent [PEPCAD]; NCT01622075).

Localized in vivo model drug delivery with intravascular ultrasound and microbubbles

An intravascular ultrasound (IVUS) and microbubble drug delivery system was evaluated in both ex vivo and in vivo swine vessel models. Microbubbles with the fluorophore DiI embedded in the shell as a model drug were infused into ex vivo swine arteries at a physiologic flow rate (105 mL/min) while a 5-MHz IVUS transducer applied ultrasound. Ultrasound pulse sequences consisted of acoustic radiation force pulses to displace DiI-loaded microbubbles from the vessel lumen to the wall, followed by higher-intensity delivery pulses to release DiI into the vessel wall. Insonation with both the acoustic radiation force pulse and the delivery pulse increased DiI deposition 10-fold compared with deposition with the delivery pulse alone. Localized delivery of DiI was then demonstrated in an in vivo swine model. The theoretical transducer beam width predicted the measured angular extent of delivery to within 11%. These results indicate that low-frequency IVUS catheters are a viable method for achieving localized drug delivery with microbubbles.

Mechanisms of postintervention and nine-month luminal enlargement after treatment of drug-eluting in-stent restenosis with a drug-eluting balloon

Using optical coherence tomography (OCT), the mechanisms of postintervention and 9-month luminal enlargement in drug-eluting stent in-stent restenosis (ISR) lesions treated with a drug-eluting balloon (DEB) were evaluated. A total of 42 patients with DEB-treated drug-eluting stent ISR lesions underwent serial OCT examination before intervention, after intervention, and at 9-month follow-up. Preintervention OCT-derived neointima was classified as either a homogeneous or nonhomogeneous pattern. Ten ISR lesions with homogeneous neointima were identified and compared with 32 ISR lesions with nonhomogeneous neointima. When comparing pre- and postintervention evaluations, changes in luminal cross-sectional area (CSA) were 3.4 mm(2) in ISR lesions with homogeneous neointima and 3.7 mm(2) in those with nonhomogeneous neointima, respectively (p = 0.529); changes in stent CSA were 2.5 mm(2) and 1.4 mm(2), respectively, p = 0.004; and changes in neointimal CSA were -0.9 mm(2) and -2.3 mm(2), respectively, p = 0.001. At 9-month follow-up, changes in luminal CSA were -2.0 mm(2) and -0.9 mm(2) in ISR lesions with homogeneous and nonhomogeneous neointima, respectively (p = 0.021); in stent CSA changed by -0.2 mm(2) in both groups (p = 0.851) and changes in neointimal CSA was 1.8 mm(2) and 0.7 mm(2), respectively (p = 0.003). At the 9-month follow-up, >50% neointimal CSA stenosis was observed in 60% and 19% of the ISR lesions with homogeneous and nonhomogeneous neointima, respectively (p = 0.020). In conclusion, the mechanism of postintervention luminal enlargement by DEB varied with the preintervention OCT-based neointimal characteristics. ISR lesions with homogeneous neointima determined by OCT were associated with greater subsequent regrowth of neointima after DEB treatment.