Is bare-metal stenting superior to balloon angioplasty for small vessel coronary artery disease? Evidence from a meta-analysis of randomized trials

Systematic Review on Role of Drug Eluting Stent (DES) Versus Drug-Coated Balloon (DCB) in Small Vessel Coronary Artery Disease

PURPOSE OF REVIEW: This review aims to explain the current advancements in the treatment modalities for small vessel coronary artery disease (SVCAD) and de novo lesions post-percutaneous coronary intervention (PCI), focusing on drug-coated stents (DES) and drug-coated balloons (DCB). Its goal is to address the lack of standards in the management of these lesions and to assess the potential of DCB as a preferential treatment strategy over DES in the long term. RECENT FINDINGS: Technological advancements have improved drug-eluting stents (DES) and drug-coated balloons (DCB) which offer a more promising avenue for managing SVCAD. According to new data, DCBs, initially recognized for their efficacy in preventing restenosis within three to five years of stent placement, may offer superior outcomes compared to DES in certain clinical scenarios. This review shows that DCBs have a favorable therapeutic profile in the treatment of SVCAD, and they could be considered as an alternative to DES. Although the initial data is compelling, definitive conclusions cannot be met without further large-scale, long-term clinical trials. The implication of these findings suggests a shift in the future of SVCAD management and requires additional research to substantiate the long-term benefits of DCB use in SVCAD. Should ongoing and future studies corroborate the current evidence, DCB could emerge as the standard of care for SVCAD, significantly influencing clinical practices and future research.

Comparison of Clinical Outcomes Among Various Percutaneous Coronary Intervention Strategies for Small Coronary Artery Disease

It remains unclear which percutaneous coronary intervention (PCI) strategy is the most preferable in patients with small-vessel coronary artery disease (CAD). We sought to evaluate the clinical efficacy of various PCI strategies for patients with small-vessel CAD through a network meta-analysis of randomized controlled trials (RCTs). We searched multiple databases for RCTs investigating the efficacy of the following PCI strategies for small-vessel CAD (<3 mm in diameter): drug-coated balloons (DCB), early-generation paclitaxel-eluting stents and sirolimus-eluting stents (SES), newer-generation drug-eluting stents (DES), bare-metal stents (BMS), cutting balloon angioplasty, and balloon angioplasty (BA). The primary outcome was the trial-defined major adverse cardiovascular events (MACE), mostly defined as a composite of death, myocardial infarction, and revascularization. The secondary outcomes included each component of MACE and angiographic binary restenosis. We performed a sensitivity analysis for RCTs without BMS or first-generation DES. Our search identified 29 eligible RCTs, including 8,074 patients among the 8 PCI strategies. SES significantly reduced MACE compared with BA (hazard ratio 0.23, 95% confidence interval 0.10 to 0.54) with significant heterogeneity (I2 = 55.9%), and the rankogram analysis showed that SES was the best. There were no significant differences between DCB and newer-generation DES in any clinical outcomes, which was consistent in the sensitivity analysis. BMS and BA were ranked as the worst 2 for most clinical outcomes. In conclusion, SES was ranked as the best for reducing MACE. There were no significant differences in clinical outcomes between DCB and newer-generation DES. BMS and BA were regarded as the worst strategies for small-vessel CAD.

Biolimus-Coated Balloon in Small-Vessel Coronary Artery Disease: The BIO-RISE CHINA Study

BACKGROUND

Drug-coated balloons are a safe and effective option for patients undergoing percutaneous coronary intervention, but prior randomized studies have exclusively used paclitaxel-coated devices.

OBJECTIVES

The aim of this study was to assess for the first time the safety and efficacy of a novel biolimus-coated balloon (BCB) in patients with small-vessel coronary disease.

METHODS

In a prospective trial conducted at 10 centers in China, 212 patients with small-vessel native coronary disease (reference vessel diameter 2.0-2.75 mm, lesion length ≤25 mm) were randomized to receive a BCB or an uncoated balloon. The primary endpoint was in-segment late lumen loss at 9 months.

RESULTS

In the per-protocol population, angiographic late lumen loss at 9 months was 0.16 ± 0.29 mm in the BCB group vs 0.30 ± 0.35 mm with the plain balloon (P = 0.001). Late luminal enlargement (positive remodeling) occurred in 29.7% of patients in the BCB group vs 9.8% of patients with plain balloons (P = 0.007). In the full analysis set population, after 12 months, target lesion failure rates were 6.7% in the BCB group vs 13.9% with the plain balloon (HR: 0.47; 95% CI: 0.19-1.16), and rates of the patient-oriented clinical outcome were 14.3% with the BCB vs 21.8% with the plain balloon (HR: 0.64; 95% CI: 0.33-1.24).

CONCLUSIONS

In this first-in-human study, a novel BCB showed superior efficacy to plain balloon angioplasty in patients with small-vessel coronary disease undergoing percutaneous coronary intervention. Positive vascular remodeling was more frequent, and there was a trend toward improved clinical outcomes. (A Randomized Trial of a Biolimus-Coated Balloon Versus POBA in Small Vessel Coronary Artery Disease [Brave]; NCT03769623).

Three Technologies That Will Guide Revascularization of Chronic Coronary Syndrome Patients into the 21st Century: A Review

Although medical therapy is the preferred first-line treatment for patients with chronic coronary syndrome (CCS), revascularization remains an important consideration. We present a review that identifies the three diagnostic technologies most important to guiding the decision to revascularize patients with CCS: (1) cardiac computed tomography, (2) intracoronary imaging, and (3) lesion-specific physiological guidance.

Invasive therapy versus conservative therapy for patients with stable coronary artery disease: An updated meta-analysis

Background

Heart disease remains the leading cause of death in the United States. Although there are clear indications for revascularization in patients with acute coronary syndromes, there is debate regarding the benefits of revascularization in stable ischemic heart disease. We sought to perform a comprehensive meta‐analysis to assess the role of revascularization compared to conservative medical therapy alone in patients with stable ischemic heart disease.

Hypothesis

There is no significant difference in all‐cause mortality or cardiovascular mortality between invasive and medical arms.

Methods

We performed a systematic literature search from January 2000 to June 2020. Our literature search yielded seven randomized controlled trials. We analyzed a total of 12 013 patients (6109 in revascularization arm and 5904 in conservative medical therapy arm). Primary outcome was all‐cause mortality. Secondary outcomes included major adverse cardiac events (MACE) (death, myocardial infarction [MI], or stroke), cardiovascular mortality, MI, and stroke. Additional subgroup analysis for all‐cause mortality was performed comparing percutaneous coronary intervention (PCI) with bare metal stent versus conservative therapy; and PCI with drug eluting stent versus conservative therapy.

Results

There was no statistically significant difference in primary outcome of all‐cause mortality between either arm (odds ratio [OR] = 0.95; 95% CI [confidence interval], 0.83 to 1.08; p = .84). There were statistically significant lower rates of MACE (death, MI or stroke) in the revascularization arm when compared to conservative arm.

Conclusions

Our analysis did not show any survival advantage of an initial invasive strategy over conservative medical therapy in patients with stable coronary artery disease (CAD).

Small vessel coronary artery disease: How small can we go with myocardial revascularization?

The issue of small coronary artery atherosclerosis represents an intriguing aspect of coronary artery disease, which is related with higher rates of peri- and post-procedural complications and impaired long-term outcome. This problem is further complicated by the unclear definition of small coronary vessel. Recent randomized controlled trials have provided new data on possible novel interventional treatment of small coronary vessels with drug-coated balloons instead of traditional new-generation drug-eluting stent implantation. Also, the conservative management represents a therapeutic option in light of the results of the recent ISCHEMIA trial. The current article provides an overview of the most appropriate definition, interventional management, and prognosis of small coronary artery atherosclerosis.

Assessment of intermediate coronary lesions by fractional flow reserve and quantitative flow ratio in patients with small-vessel disease

BACKGROUND

Quantitative flow ratio (QFR) has recently been introduced as a novel, less-invasive, adenosine-free measure for functional coronary lesion assessment. Whether reference vessel dimensions affect functional lesion assessment is uncertain.

METHODS

A total of 436 patients with 516 interrogated coronary vessels by means of FFR were included in the study. Patients were dichotomized according to the median reference vessel diameter (group 1: ≤2.8 mm and group 2: >2.8 mm). QFR analyses were performed offline at the institution's core laboratories.

RESULTS

Reference vessel diameter was 2.5 [2.3-2.7] mm in group 1 and 3.3 [3.0-3.6] mm in group 2. Diameter stenosis (41.4 [36.4-47.6] % vs. 41.4 [36.4-45.7] %, p = .20) did not differ among groups. Median FFR values were lower in group 1 (0.87 [0.81-0.92]) as compared with group 2 (0.89 [0.84-0.93], p = .001). Consistently, QFR values were lower in group 1 (0.88 [0.82-0.92]) than in group 2 (0.91 [0.85-0.94], p = .001). The proportions of functionally significant coronary lesions as defined by FFR ≤0.80 were 24.1% and 14.2% in groups 1 and 2 (p = .005), and as defined by cQFR ≤0.80 20.4% and 11.8% (p = 0.009), respectively. In ROC analysis for an FFR ≤.80, the AUC was 0.89 (95% CI 0.85-0.93, p < .001) in group 1 and 0.81 (95% CI 0.76-0.86, p < .001) in group 2.

CONCLUSIONS

These results suggest that QFR measurements are accurate irrespective of the reference vessel diameter. Future studies are needed to elucidate the higher percentage of functionally significant lesions observed in small vessels despite a similar angiographic lesion severity.

Role of Drug-coated Balloons in Small-vessel Coronary Artery Disease

Percutaneous coronary intervention of small-vessel coronary artery disease (SVD) remains challenging due to difficulties with device delivery and high restenosis rate, even with the use of newer-generation drug-eluting stents. Drug-coated balloons represent an attractive emerging percutaneous coronary intervention option in patients with SVD. Potential advantages of drug-coated balloons in SVD include enhanced deliverability because of their small profile, avoidance of foreign-body implantation, and shorter duration of dual antiplatelet therapy.

Two-year results after coronary stenting of small vessels in Japanese population using 2.25-mm diameter sirolimus-eluting stent with bioresorbable polymer: primary and long-term outcomes of CENTURY JSV study

Percutaneous coronary intervention (PCI) in coronary artery disease (CAD) with very small vessels remains challenging. The aim of this study is to evaluate the safety and effectiveness of the 2.25-mm diameter Ultimaster sirolimus-eluting stent in the treatment of Japanese patients with CAD due to lesions in very small vessels. The CENTURY JSV study is a prospective, multicentre, single-arm study. Seventy patients with lesions deemed suitable for implantation of a 2.25-mm diameter stent were enrolled at seven hospitals in Japan. Patients underwent clinical follow-up at 1-, 9-month, 1-, and 2-year after the PCI procedure. The primary endpoint was the major adverse cardiac event (MACE), a composite of cardiac death, target vessel myocardial infarction (MI), and clinically driven target lesion revascularization (TLR) free rate at 9-month following the procedure. The MACE-free rate was 97.1%, and the lower limit of the two-sided 95% confidence interval (CI) was 90.1%, which exceeded the threshold of 80% set as the performance goal. Angiographic in-stent and in-segment late loss at 9-month were 0.22 ± 0.31 and - 0.02 ± 0.34 mm, respectively. Between 9 months and 2 years, two additional TLRs occurred. Stent thrombosis, bleeding and vascular complication did not occur throughout 2 years. The 2.25-mm diameter Ultimaster^® bioresorbable-polymer sirolimus-eluting stent is safe and effective for treating lesions in very small coronary arteries throughout 2 years after stent implantation.Clinical trial registration: UMIN000012928.

The outcomes of patients with very small coronary artery disease treated with thin strut cobalt chromium bare metal stents: an observational study

BACKGROUND

Percutaneous coronary interventions (PCI) in coronary artery disease (CAD) with very small vessel diameters remains controversial and challenging. These lesions are usually more diffuse, calcified and tortuous. The usage of thin strut bare metal stents (BMS) with excellent crossing profiles in a very small caliber coronary lesions has increased the likelihood of procedural success.

OBJECTIVES

This observational study assessed the 9-month clinical outcomes in an 'all-comers' population with very small caliber CAD after implantation of thin strut cobalt chromium BMS.

METHODS

Thin strut cobalt chromium BMS implantation in a priori pre-defined subgroups was investigated in a non-randomized, international, multi-center 'all-comers' observational study. Primary end-point was the 9-month clinically driven target lesion revascularization (TLR) rate. Secondary end-points included the 9-month major adverse cardiac event (MACE) and procedural success rates. Data collection was done using an established electronic data acquisition form with built-in plausibility checks.

RESULTS

A total of 783 patients with a mean age of 70.4 ± 12.8 years were enrolled, 205 (26.2 %) of them had vessel diameters of 2.5 mm and smaller which was defined as CAD with very small reference vessel calibers. Older age and diabetics were associated with higher incidences of very small caliber vessels. The mean reference vessel diameter in the very small vessel group was 2.05 ± 0.27 mm and mean diameter for vessels >2.5 mm was 3.41 ± 0.55 mm. Pre-dilatation was performed more often in the very small vessel patients (52.2 vs. 42.2 %; p value 0.007). There was no difference in the overall technical success rates in very small vessel disease group (97.9 vs. 97.7 %). The 9-month TLR rate was 6.3 % for the very small vessels and 3.7 % for vessels >2.5 mm (p = 0.129). The 9-month and in-hospital MACE rates in the very small vessel group and patient with vessel diameters >2.5 mm were not significantly different (13.1 vs. 9.2 %; p = 0.1265 and 5.2 vs. 3.7 %; p = 0.349) respectively.

CONCLUSION

This study has demonstrated that the use of thin strut cobalt chromium BMS in very small vessel CAD was reasonably safe and efficacious in the context of 'real-world' practice.

Clinical and Imaging Outcomes up to 1 Year Following Balloon Angioplasty for Isolated Penile Artery Stenoses in Patients With Erectile Dysfunction: The PERFECT-2 Study

PURPOSE

To assess the angiographic and clinical outcomes in patients with erectile dysfunction and isolated penile artery stenoses treated by balloon angioplasty.

METHODS

In this prospective study, 22 patients (mean age 61.0±7.6 years, range 50-79) with erectile dysfunction and 34 isolated penile artery stenoses (mean 74.9%±9.1%) were enrolled and underwent balloon angioplasty. The mean International Index for Erectile Function-5 (IIEF-5) score at baseline was 10.3±4.5. The mean lesion length was 11.1±9.0 mm (mean reference vessel diameter 1.7±0.4 mm). The primary endpoint was in-segment restenosis ≥50% by pelvic computed tomography angiography (CTA) at 8 months. The 1-year sustained clinical success (IIEF-5 score ≥22 or a ≥4-point change in the IIEF-5 score and no later decline by ≥4) was the secondary outcome measure.

RESULTS

Procedural success was achieved in 31 (91%) of 34 stenotic lesions; there was 1 flow-limiting dissection and 2 arteries with >30% residual stenosis. At 8 months, 14 of 34 lesions in 13 of 22 patients had CTA-documented binary restenosis. At 1 year, sustained clinical success was achieved in 11 of 22 patients. Of the 9 patients not developing binary restenosis, 8 achieved sustained clinical success.

CONCLUSION

Our findings establish the safety and efficacy of penile artery angioplasty for patients with erectile dysfunction and isolated penile artery stenoses. They also highlight the unmet need for a more enduring treatment strategy for penile artery stenotic disease.

Vessel Size and Long-Term Outcomes After Limus-Based Drug-Eluting Stent Implantation Focusing on Medium- and Small-Diameter Vessels

Introduction:

This study aimed to evaluate the efficacy and safety of limus-based drug-eluting stent (DES) implanted in medium or small coronary vessels during a very long-term follow-up period.

Methods:

A total of 2383 patients treated with 2916 limus-based DES between April 2003 and March 2015 were evaluated. The enrolled patients were stratified into 3 groups according to the reference vessel diameter: group A: ≤2.5 mm; group B: 2.51 to 3.00 mm; group C: 3.01 to 3.50 mm.

Results:

Group A had a significantly higher loss index and binary restenosis rate than the other 2 groups at 9 months of angiographic follow-up. Group A also had a significantly higher rate of target lesion revascularization and a lower rate of major adverse cardiovascular event–free survival than the other 2 groups after a follow-up period of 68 ± 59 months. The long-term cardiovascular event–free survival curves based on a Cox regression model showed large vessel size, and second-generation DES had better outcomes.

Conclusion:

An inverse relationship between vessel size (≤3.5 mm) and clinical outcomes was noted in patients who received limus-based DES implantation.

Small-vessel treatment with contemporary newer-generation drug-eluting coronary stents in all-comers: Insights from 2-year DUTCH PEERS (TWENTE II) randomized trial

BACKGROUND

Treatment of lesions in small vessels was associated with worse clinical outcome, and various definitions of "small vessels" have been used. Data with novel drug-eluting stents are scarce.

METHODS

To compare the outcome of patients with vs without small-vessel treatment, we assessed 2-year follow-up data of the DUTCH PEERS randomized trial (ClinicalTrials.gov: NCT01331707), in which 1,811 all-comers were treated with contemporary zotarolimus-eluting (Resolute Integrity) or everolimus-eluting (Promus Element) stents. Primary end point was target lesion failure (TLF), a composite of cardiac death, target vessel myocardial infarction, and target lesion revascularization.

RESULTS

The rates of TLF (9.5% vs 5.4%; P log rank = .001) and 2 individual components thereof-target vessel myocardial infarction (3.1% vs 1.3%; P log rank = .006) and target lesion revascularization (4.8% vs 2.8%; P log rank = .02)-were higher among 798 (44.1%) patients treated in at least one small vessel (<2.50 mm by quantitative coronary angiography). Multivariate analysis with propensity score adjustment demonstrated that treatment of small-vessel lesions independently predicted TLF at 2-year follow-up (hazard ratio 1.60, 95% CI 1.09-2.34). Patients with the smallest target vessel being <2.25 mm had TLF rates similar to patients with smallest target vessels of 2.25 to <2.50 mm; however, patients treated in vessels no smaller than 2.50 to <3.00 mm and patients treated in vessels ≥3.00 mm had lower TLF rates (9.3%, 9.8%, 5.0%, and 5.8%, respectively; P log rank = .009).

CONCLUSION

Patients treated with novel drug-eluting stents in small-vessel lesions had higher adverse event rates than did patients who had no small-vessel treatment. Our data suggest that with current stents, a vessel diameter <2.50 mm is a suitable threshold to identify small target vessels.

The use of paclitaxel coated balloon (PCB) in acute coronary syndrome of small vessel de novo lesions: an analysis of a prospective 'real world' registry

Background

Paclitaxel-coated balloon (PCB) angioplasty in small vessel de novo lesions has favourable outcome and appears to be an alternative to stent implantation. However there is limitted data on its use specifically in small vessel acute coronary syndrome (ACS).

Methods

We analyse patients data from the SeQuent Please Small Vessel ‘PCB only’ Registry. It was an international, prospective, multicentre registry which enrolled patients with de novo lesions of small vessel diameter (≥2.0, ≤2.75 mm). Patients were divided into the ACS group and the non-ACS group and comparison made between the two groups. The primary end-point was clinically driven target lesion revascularisation (TLR) at 9 months. Secondary end-points were acute technical success, 30-day and 9-month major adverse cardiac events (death, myocardial infarction or TLR) (MACE) and the occurence of definite lesion and vessel thrombosis.

Results

A total of 447 patients were enrolled for this registry of which 105 (23.5 %) patients were ACS (STEMI and NSTEMI). The procedural success rate was 98.1 % in ACS group. The mean vessel diameter for the ACS and non-ACS group were 2.15 ± 0.36 and 2.14 ± 0.35 respectively. Similar mean lesion length of around 15.5 mm was recorded in both groups. Additional stenting was required in 9.3 % ACS and 6.5 % non-ACS, p = 0.308. Reasons for additional stenting were target lesion related dissection (57.6 %) or non-target lesion stenosis (41.2 %). More than half of the patients had 4 weeks of aspirin/clopidogrel (57.1 % ACS, 60.5 % non-ACS). No significant difference between the ACS and non-ACS groups with regards to the duration and types of DAPT during follow up. At 30-day, MACE rate were (0 % ACS vs 0.3 % non-ACS, p = 0.599). At 9 months TLR rates were (1.2 % ACS vs 4.3 % non-ACS, p = 0.180) and MACE rates (3.6 % ACS vs 5.0 % non-ACS, p = 0.601).

Conclusion

PCB in ACS with small vessel de novo lesions has low 30-day and 9-month TLR/MACE rates comparable to non-ACS small vessels. Thus it appears to be an alternative to stent implantation in the treatment ACS.

Comparison of Paclitaxel-Coated Balloon Treatment and Plain Old Balloon Angioplasty for De Novo Coronary Lesions

PURPOSE

This study compared the angiographic outcomes of paclitaxel-coated balloon (PCB) versus plain old balloon angioplasty (POBA) treatment for de novo coronary artery lesions. At present, there is no available data comparing the efficacy of PCB versus POBA for the treatment of de novo coronary lesions.

MATERIALS AND METHODS

This multicenter retrospective observational study enrolled patients with de novo coronary lesions with a reference vessel diameter between 2.5 mm and 3.0 mm and lesion length ≤ 24 mm who were successfully treated with PCB or POBA. Angiographic measurements and quantitative coronary analysis were performed before and after the procedure, and at 9 months follow-up.

RESULTS

A total of 72 patients (49 receiving PCB and 23 receiving POBA) were enrolled in this study. Late luminal loss was -0.12 ± 0.30 mm in the PCB group and 0.25 ± 0.50 mm in the POBA group (p<0.001). There was a higher percentage of binary restenosis (diameter stenosis ≥ 50%) in POBA, compared to PCB (30.4%, n=7 vs. 4.1%, n=2, p<0.001). Target vessel revascularization was higher in the POBA group (13.0%, n=3 vs. 0%, p=0.033).

CONCLUSION

PCB treatment of de novo coronary lesions showed better 9-month angiographic outcomes than POBA treatment alone.

Composite outcomes in 2.25-mm drug eluting stents: a systematic review

BACKGROUND

Coronary atherosclerosis often involves small-caliber coronaries, yet the safety and efficacy of 2.25-mm DES have been poorly defined, with a general lack of separation of 2.25 with 2.5-mm performance. No randomized head-to-head 2.25 mm DES studies have been reported. There are several single-arm prospective studies, and we aim to systematically review all published specific 2.25-mm data to estimate composite DES-specific performance and highlight current knowledge gaps.

METHODS

We performed a systematic literature search of PubMed, EMBASE, Web of Science and Cochrane database for clinical trials of 2.25-mm DES. Angiographic and composite clinical outcomes were compared with descriptive statistics.

RESULTS

2.25 mm-Paclitaxel (PES), sirolimus (SES), everolimus (EES) and platinum chromium EES DES-specific outcomes have been reported. Death at 12 months for SES, PES, EES and platinum chromium EES was 1.3%, 3.0%, 1.5%, and 4.4%. Rates of target vessel revascularization at 12 months for SES, PES, EES and platinum chromium EES were 5.7%, 13.3%, 8.8%, and 3.3%. Angiographic outcomes at 9 months to one year were as follows: mean late lumen loss (LLL) for SES, PES, and EES was 0.15 ± 0.11-mm, 0.28 ± 0.11-mm, and 0.16 ± 0.41-mm and mean diameter restenosis for SES, PES, and EES were 29.5 ± 6.2%, 34.7 ± 4.2%, and 20.9 ± 22.5%. Reported stent thrombosis rates for 2.25-mm DES were low ranging from 0% to 2.2% in up to 24-months of follow-up.

CONCLUSIONS

This systematic review summarizes and tabulates all available specific data on 2.25-mm DES. Based on our descriptive analysis, 2.25-mm DESs have a favorable safety and efficacy profile for the treatment of very small coronary lesions.

Diagnostic accuracy and discrimination of ischemia by fractional flow reserve CT using a clinical use rule: results from the Determination of Fractional Flow Reserve by Anatomic Computed Tomographic Angiography study

BACKGROUND

Fractional flow reserve (FFR) is the gold standard for determining lesion-specific ischemia. Computed FFRCT derived from coronary CT angiography (coronary CTA) correlates well with invasive FFR and accurately differentiates between ischemia-producing and nonischemic lesions. The diagnostic performance of FFRCT when applied in a clinically relevant way to all vessels ≥ 2 mm in diameter stratified by sex and age has not been previously examined.

METHODS

Two hundred fifty-two patients and 407 vessels underwent coronary CTA, FFRCT, invasive coronary angiography, and invasive FFR. FFRCT and FFR ≤ 0.80 were considered ischemic, whereas CT stenosis ≥ 50% was considered obstructive. The diagnostic performance of FFRCT was assessed following a prespecified clinical use rule which included all vessels ≥ 2 mm in diameter, not just those assessed by invasive FFR measurements. Stenoses <30% were assigned an FFR of 0.90, and stenoses >90% were assigned an FFR of 0.50. Diagnostic performance of FFRCT was stratified by vessel diameter, sex, and age.

RESULTS

By FFR, ischemia was identified in 129 of 252 patients (51%) and in 151 of 407 vessels (31%). Mean age (± standard deviation) was 62.9 ± 9 years, and women were older (65.5 vs 61.9 years; P = .003). Per-patient diagnostic accuracy (83% vs 72%; P < .005) and specificity (54% vs 82%, P < .001) improved significantly after application of the clinical use tool. These were significantly improved over standard coronary CTA values before application of the clinical use rule. Discriminatory power of FFRCT also increased compared with baseline (area under the receiver operating characteristics curve [AUC]: 0.93 vs 0.81, P < .001). Diagnostic performance improved in both sexes with no significant differences between the sexes (AUC: 0.93 vs 0.90, P = .43). There were no differences in the discrimination of FFRCT after application of the clinical use rule when stratified by age ≥ 65 or <65 years (AUC: 0.95 vs 0.90, P = .10).

CONCLUSIONS

The diagnostic accuracy and discriminatory power of FFRCT improve significantly after the application of a clinical use rule which includes all clinically relevant vessels >2 mm in diameter. FFRCT has similar diagnostic accuracy and discriminatory power for ischemia detection in men and women irrespective of age using a cut point of 65 years.

A multistudy analysis investigating systematic differences in cardiovascular trial results between Europe and Asia

OBJECTIVE

To assess whether there are differences in the results of cardiovascular trials between Europe and Asia using data from an extensive collection of randomised controlled trials.

STUDY DESIGN AND SETTING

All meta-analyses containing randomised controlled trials (RCT's) for the treatment or prevention of cardiovascular diseases were searched for in The Cochrane Library (2000-2008) and MEDLINE (2005-2008). Analysis was then conducted within and over each meta-analysis which satisfied given criteria. Separate estimates of treatment effect were calculated for Europe and Asia in each meta-analysis and then compared. Estimates of a common inter-continental difference over all meta-analyses were also calculated and meta-regression was performed. This was performed for both fatal and non-fatal end points.

RESULTS

The literature search identified 59 meta-analyses that satisfied the inclusion criteria. After exclusion, the number of meta-analyses reporting greater effect sizes in Asia than in Europe was significantly more than would be expected by chance (fatal 12/14, p=0.013; non-fatal 23/32, p=0.020).

CONCLUSIONS

This study provides some evidence that for cardiovascular interventions treatment effect estimation differs between Europe and Asia, with respect to both fatal and non-fatal end points.

Coronary artery stents: advances in technology

The introduction of percutaneous coronary intervention (PCI) in the late 1970s revolutionized the management of stable and unstable coronary artery disease, providing an effective, quick, safe, and increasingly widely available method for coronary revascularization for many patients. Rapid development in this field led to the introduction of a number of new technologies, including intracoronary stents that have resulted in improved efficacy and long-term safety. In this manuscript we review the experience with the 2 major available classes of stents (bare metal [BMS], drug-eluting [DES]) and describe the delivery systems for these stents. An evidence review of the large trial data comparing balloon angioplasty, BMS, and DES demonstrates the incremental advances over time, with the latest generation of DES achieving the lowest rates of restenosis, stent thrombosis, and recurrent myocardial infarction. In addition, we provide an overview of the latest developments in stent technology, including the introduction of bioresorbable stents and new stent delivery systems. These latest advances are hoped to further improve outcomes while reducing costs due to a reduction in the need for future procedures and hospitalizations due to recurrent coronary disease.

Miniaturized self-expanding drug-eluting stent in small coronary arteries: late effectiveness

Background

Small vessels represent a risk factor for restenosis in percutaneous coronary angioplasty (PCA). The Sparrow^® self-expanding drug-eluting stent, which has a lower profile than the current systems, has never been tested in this scenario.

Objectives

To evaluate the late effectiveness of the Sparrow^® drug-eluting stent, regarding in-stent late lumen loss (LLL).

Methods

Patients with ischemia, symptomatic or documented, were submitted to PCA in vessels with reference diameter < 2.75 mm, divided into two groups regarding Sparrow^® stent type: group 1: Sparrow^® drug-eluting stent (DES), group 2: Sparrow^® bare metal stent (BMS). Clinical follow-up duration was 12 months. Evaluation using quantitative coronary angiography (QCA) was performed immediately and at 8 months. A decrease of over 65% of in-stent LLL with DES was estimated to calculate sample size. IBM^® SPSS software, release 19 (Chicago, Illinois, USA) was used for the statistical analysis.

Results

A total of 24 patients were randomized, 12 in each group. The DES and BMS groups were similar in age (63.25 ± 10.01 vs. 64.58 ± 11.54, p = 0.765), male gender (58.3% vs. 33.3%, p = 0.412), risk factors and all angiographs aspects. Immediate results were satisfactory in both groups. At 8 months in-stent late lumen loss was significantly lower in DES than in BMS group (DES vs. BMS 0.25 ± 0.16 0.97 ± 0.76, p = 0.008).

Conclusion

In small-vessel PCA, the Sparrow^® DES determined significant reduction in in-stent LLL, when compared to Sparrow^® BMS.

Percutaneous revascularization strategies in small-vessel disease

Percutaneous coronary intervention (PCI) of small coronary vessels represents a real challenge for myocardial revascularization because of the high risk of stent-restenosis and increased risk of adverse clinical events. Moreover, small coronary arteries supply small myocardial territories therefore questioning the clinical significance of small-vessel stenoses. The definition of small-vessel disease and PCI-strategies used are very heterogeneous across studies. The present review will focus on percutaneous coronary revascularization in patients with small vessel coronary artery disease.

Everolimus-eluting stents in interventional cardiology

Bare metal stents have a proven safety record, but limited long-term efficacy due to in-stent restenosis. First-generation drug-eluting stents successfully countered the restenosis rate, but were hampered by concerns about their long-term safety. Second generation drug-eluting stents have combined the low restenosis rate of the first generation with improved long-term safety. We review the evolution of drug-eluting stents with a focus on the safety, efficacy, and unique characteristics of everolimus-eluting stents.

New technologies aimed at percutaneous intervention in the small coronary artery

Percutaneous coronary intervention (PCI) of small vessels can be complicated by technically difficult access to the target lesion, an increased risk of major adverse cardiac events and in-stent restenosis requiring repeat revascularization. Conventional management of such lesions is with drug-eluting stent implantation; however, these have only partly attenuated the problem. In response, several medical device companies are competing to produce new technologies aimed at PCI in small coronary arteries. Such innovations include thin-strutted stents, stent-on-a-wire systems, drug-coated balloons, endothelial progenitor cell-catching stents and biodegradable stent systems. To date, none of these techniques have been sufficiently validated for use in small coronary arteries to justify a change in practice; however, small-vessel coronary artery disease is an increasingly common problem, and PCI of target lesions with reference vessel diameter <3.0 mm is likely to increase, especially in view of the increasing prevalence of diabetes, warranting further well-designed studies. The prospect of mounting a self-expandable biodegradable drug-eluting stent directly onto a guidewire could potentially be an exciting future development.

Wingspan stents for the treatment of symptomatic atherosclerotic stenosis in small intracranial vessels: safety and efficacy evaluation

BACKGROUND AND PURPOSE

Until now, endovascular treatment of symptomatic atherosclerotic stenosis in small intracranial arteries (≤2.5 mm) was limited. We evaluated the safety and efficacy of the treatment by using Wingspan stents in arteries of this caliber.

MATERIALS AND METHODS

From March 2007 to July 2010, 53 symptomatic intracranial stenoses with narrowing of at least 50% in 53 patients were treated by using Wingspan stents. Clinical manifestations and imaging features were recorded.

RESULTS

The technical success rate was 98.1%. There were no serious complications, with the exception of 1 patient who experienced a small cerebral hemorrhage caused by perforation of microwire. Thirty-nine patients (74%) were available for follow-up imaging with DSA. ISR was documented in 13 of these patients, including 2 patients with symptomatic ISR. The median length of the vascular lesions was 5.39 mm, and patients whose vascular lesions were longer than 5.39 mm had a much higher incidence of ISR than patients whose vascular lesions were shorter than 5.39 mm (53% versus 15%, respectively). The median ratio of the reference artery diameter to the stent diameter was 0.78, and patients whose ratio was smaller than 0.78 had a much higher incidence of ISR than patients whose ratio was larger than 0.78 (53% versus 15%, respectively).

CONCLUSIONS

In our series, percutaneous transluminal angioplasty and stent placement of small intracranial arteries by using Wingspan stents was safe. The ISR rate was relatively high; most patients having ISR were asymptomatic. Further follow-up is needed to assess the long-term efficacy of this procedure.

Long-term clinical outcome in patients with small vessel disease treated with drug-eluting versus bare-metal stenting

BACKGROUND

DES is superior to BMS in reducing restenosis and repeat revascularization. Available data are less convincing in small vessel disease. Aim of our study is to assess long-term clinical outcome of drug-eluting stents (DES) vs. bare-metal stents (BMS) in small coronary vessel disease.

METHODS

Procedural and long-term clinical outcomes were assessed in consecutive patients (pts) treated with stenting of native small coronary arteries (reference vessel diameter and implanted stent < 3mm).

RESULTS

Pts enrolled were 645: DES group (n = 277) presented more frequently diabetes (173 [62%] vs. 32 [9%], P < .0001), higher body mass index (27 ± 5 vs. 26 ± 4, P = .01) and with previous PCI (115 [42%] vs. 118 [32%], P = .01) as compared to BMS group (n=368). DES group presented more frequently with unstable angina (46 [17%] vs. 38 [10%], P = .02); BMS group presented more frequently with myocardial infarction (103 [28] vs. 43 [15], P = .0002). Reference vessel (2.27 ± 0.36 vs. 2.24 ± 0.36, P = .29), minimal lumen (0.81 ± 0.32 vs. 0.80 ± 0.31, P = .84) and stent diameter (2.59 ± 0.17 vs. 2.60 ± 0.15, P = .69) did not differ between the 2 groups. Lesion length was significantly higher in DES group (15.85 ± 6.81 vs. 13.66 ± 7.18, P = .01). At a median clinical follow-up of 3.0 years (IQR range 2.2-4.6), pts with DES showed significantly lower major adverse cardiac events (MACE, HR 0.51, 95%CI 0.33-0.78) and target vessel revascularization (TVR, HR 0.44, 95%CI 0.25-0.78). No differences were observed between the two groups as to death, myocardial infarction and stent thrombosis.

CONCLUSIONS

In small vessel disease, DES was more frequently implanted in pts at higher risk of restenosis, though it demonstrated to be more effective than BMS in reducing MACE and TVR at long-term follow-up.

Paclitaxel coated balloons for coronary artery interventions: a comprehensive review of preclinical and clinical data

After the "mechanical era" in interventional cardiology (represented by balloon angioplasty and bare metal stent implantation), arrived the "local dispensing" era, began with the intracoronary delivery of antithrombotic or antirestenotic drugs. However, even drug eluting stents have some pitfalls and cannot be used in all clinical subsets. In this article we will review the significant data on the paclitaxel-coated balloons for the treatment of coronary artery disease. Particularly, we will review the rationale of this new treatment strategy, the preclinical data and will focus on available clinical studies in humans. After the initial boost of the paclitaxel coated balloons with the Paccocath technology in in-stent restenotic lesions, the experimentation of newer devices in native coronary arteries raised some concerns on their efficacy and safety. We will comment on this topic trying to understand the reasons of this failure, and will discuss on possible future developments and applications for these devices for the treatment of coronary artery disease.

Drug-eluting stents perform better than bare metal stents in small coronary vessels: a meta-analysis of randomised and observational clinical studies with mid-term follow up

BACKGROUND

We tested drug-eluting stent (DES) and bare metal stent (BMS) performance in small coronary vessels by means of meta-analysis of all available clinical studies.

METHODS

The analysis included randomised controlled trials (RCT), subgroups of RCT and observational studies with a follow-up of at least six months comparing the use of DES and BMS during percutaneous interventions involving small coronary arteries (diameter<3mm). The primary endpoint was target vessel failure (TVF); the others were pooled and isolated major adverse cardiovascular events (MACE), stent thrombosis (ST), binary restenosis and late lumen loss at the longest available follow-up. The effect of treatment was evaluated in terms of odds ratios (OR) and 95% confidence intervals (95% CI) for binary variables, and mean difference (MD)± standard deviation (SD) for continuous variables. Fixed- or random-effect models were used depending on the statistical heterogeneity of studies. The analyses of major endpoints were stratified by study type, length of follow-up, and type of DES.

RESULTS

We pooled 12 studies involving 3182 patients. Trial heterogeneity was a minor issue. TVF (OR: 0.35; CI: 0.24-0.51), MACE (OR: 0.36; CI: 0.29-0.45), binary restenosis (OR: 0.15; CI: 0.12-0.20) and late lumen loss (MD: -0.46; SD: -0.55 to -0.38) all significantly improved with DES treatment; ST (OR: 0.63; CI: 0.34-1.17) was not statistically different between studies.

CONCLUSIONS

DES are superior to BMS in terms of their efficacy in managing small coronary arteries (diameter<3mm), and at least equivalent in terms of safety. The use of DES should be considered the treatment of choice in this setting.

Effectiveness of drug-eluting stents versus bare-metal stents in large coronary arteries in patients with acute myocardial infarction

This study compared clinical outcomes of drug-eluting stents (DES) versus bare-metal stents (BMS) in large coronary arteries in patients with acute myocardial infarction (MI). A total of 985 patients who underwent single-vessel percutaneous coronary intervention (PCI) in large coronary arteries (≥ 3.5 mm) in lesions < 25 mm were divided into DES group (n = 841) and BMS group (n = 144). Clinical outcomes during 12 months were compared. In-hospital outcome was similar between the groups. At six months, death/MI rate was not different. However, DES group had significantly lower rates of target-lesion revascularization (TLR) (1.7% vs 5.6%, P = 0.021), target-vessel revascularization (TVR) (2.2% vs 5.6%, P = 0.032), and total major adverse cardiac events (MACE) (3.4% vs 11.9%, P = 0.025). At 12 months, the rates of TLR and TVR remained lower in the DES group (2.5% vs 5.9%, P = 0.032 and 5.9% vs 3.1%, P = 0.041), but the rates of death/MI and total MACE were not statistically different. The use of DES in large vessels in the setting of acute MI is associated with lower need for repeat revascularization compared to BMS without compromising the overall safety over the course of one-year follow-up.

Small coronary vessel angioplasty: outcomes and technical considerations

Small vessel (<3 mm) coronary artery disease is common and has been identified as independent predictor of restenosis after percutaneous coronary intervention. It remains controversial whether bare-metal stent (BMS) implantation in small vessels has an advantage over balloon angioplasty in terms of angiographic and clinical outcomes. Introduction of drug-eluting stent (DES) has resulted in significant reduction in restenosis and the need for repeat revascularization. Several DESs have been introduced resulting in varying reduction in outcomes as compared with BMS. However, their impact on outcomes in small vessels is not clearly known. It is expected that DES could substantially reduce restenosis in smaller vessels. Large, randomized studies are warranted to assess the impact of different DESs on outcomes in patients with small coronary arteries.

Clinical and angiographic features of small vessel stenting in the drug-eluting stent era

HYPOTHESIS

This study was designed to investigate the clinical and angiographic features and procedural outcomes of small-vessel stenting in a real-world experience during the transition era between drug-eluting stents (DES) and bare-metal stents (BMS).

METHODS

Using one of the largest single-institutional cohorts, this study evaluated all patients who underwent percutaneous coronary intervention (PCI) from 2002 through 2005. Analysis was restricted to patients receiving a single stent or undergoing balloon-only angioplasty in a single anatomic site. Small-vessel stents (SVS) were defined as 2.00 to 2.75 mm and large-vessel stents (LVS) as 3.00 to 4.00 mm in diameter.

RESULTS

A total of 19,580 stents were placed in 10,396 patients. Of 6208 patients fulfilling inclusion criteria, 1630 (26.3%) received SVS, and 4578 (73.7%) received LVS. The SVS group had more female (35.5% vs 26.3%, P < .001) and diabetic patients (27.9% vs 24.2%, P < .003) than the LVS group. Compared with LVS, SVS lesions were shorter (14.5 +/- 5.8 mm vs 15.7 +/- 6.4 mm, P < .0001) and more complex (66% vs 53% class B2/C lesions, P = .041). Indicators of procedural difficulty, including greater contrast volume, number of devices, total inflation time, and fluoroscopy time, were more commonly observed in the SVS group. After adjustment for confounding factors, the incidence of small treatment vessel diameter was significantly higher among the DES vs the BMS group (odds ratio [OR]: = 1.94, 95% confidence interval [CI]: 1.56-2.36).

CONCLUSIONS

In addition to identifying distinct patient, lesion, and procedural performance characteristics, our study, one of the largest single-center experiences in small-vessel PCI, suggests that the availability of DES substantially increased the use of SVS, as opposed to balloon-only angioplasty, in this anatomically challenging setting.

Treatment of small coronary arteries with a paclitaxel-coated balloon catheter

BACKGROUND

Treatment of lesions in small coronary arteries by percutaneous transluminal coronary intervention is limited by a high recurrence rate. We assessed the use of a paclitaxel-coated balloon in this indication.

METHODS

One-hundred eighteen patients with stenoses in small coronary vessels were treated by a paclitaxel-coated balloon (3 microg/mm(2)). The main inclusion criteria encompassed diameter stenosis of > or =70% and < or =22 mm in length with a vessel diameter of 2.25-2.8 mm. Follow-up angiography was performed at scheduled 6-month post-intervention or whenever driven by clinical or electrocardiographic signs of ischemia. The primary endpoint was angiographic in-segment late lumen loss.

RESULTS

Eighty-two of 118 patients (70%) with a vessel diameter of 2.35 +/- 0.19 mm were treated with the drug-coated balloon only, while 32 patients required additional stent deployment. The mean in-segment late lumen loss was 0.28 +/- 0.53 mm. In patients treated with the drug-coated balloon only, the in-segment late lumen loss was 0.16 +/- 0.38 mm. At 12 months, the rate of major adverse cardiac events was 15% which was primarily due to the need for target lesion revascularization in 14 patients (12%). In those with additional bare metal stent implantation geographical mismatch between coated-balloon dilatation and stent implantation was significantly associated with the occurrence of restenosis.

CONCLUSION

Treatment of coronary stenosis in small coronary vessels with the paclitaxel-coated balloon was well tolerated. It may offer an alternative to the implantation of a drug-eluting stent (ClinicalTrials.gov Identifier: NCT00404144).

New stent design for use in small coronary arteries during percutaneous coronary intervention

Patients with diabetes mellitus, of female gender, increased age, and/or with peripheral vascular disease often develop coronary stenoses in small caliber vessels. This review describes treatment of these lesions with the paclitaxel-eluting 2.25 mm TAXUS^® Liberté^® Atom™ stent. Given the same stent composition, polymer, antirestenotic drug (paclitaxel), and release kinetics as the first-generation 2.25 mm TAXUS^® Express^® Atom™ stent, the second-generation TAXUS Liberté Atom stent incorporates improved stent design characteristics, including thinner struts (0.0038 versus 0.0052 inches), intended to increase conformability and deliverability. In a porcine noninjured coronary artery model, TAXUS Liberté Atom stent implantation in small vessels demonstrated complete strut tissue coverage compared with the bare metal stent control, suggesting a similar degree of tissue healing between the groups at 30, 90, and 180 days. The prospective, single-armed TAXUS ATLAS Small Vessel trial demonstrated improved instent late loss (0.28 ± 0.45 versus 0.84 ± 0.57 mm, P < 0.001), instent binary restenosis (13.0% versus 38.1%, P < 0.001), and target lesion revascularization (5.8% versus 17.6%, P < 0.001) at nine months with the TAXUS Liberté Atom stent as compared with the bare metal Express stent control, with similar safety measures between the two groups. The TAXUS Liberté Atom also significantly reduced nine-month angiographic rates of both instent late loss (0.28 ± 0.45 versus 0.44 ± 0.61 mm, P = 0.03) and instent binary restenosis (13.0% versus 25.9%, P = 0.02) when compared with the 2.25 mm TAXUS Express Atom control. The observed reduction in target lesion revascularization with the TAXUS Liberté Atom compared with the TAXUS Express Atom at nine months (5.8% versus 13.7%, P = 0.02) was sustained through three years (10.0% versus 22.1%, P = 0.008) with similar, stable safety outcomes between the groups. In conclusion, these data confirm the safety and favorable performance of the TAXUS Liberté Atom stent in the treatment of small coronary vessels.

Perioperative handling of patients on antiplatelet therapy with need for surgery

The widespread use of metal stents and drug-eluting stents has shown the extent to which patients with unstable coronary perfusion depend on antiplatelet drugs, and how their risk of late thrombosis depends on the long-term use of agents such as clopidogrel. It has also been shown that the risk of surgical bleeding, if antiplatelet drugs are continued, is lower than that of coronary thrombosis if they are withdrawn. Thus, except for low-risk settings, the practice of withdrawing antiplatelet drugs 5-10 days prior to surgical procedures should be changed. The following suggestions are meant to provide a guideline in this respect. Most of the current surgical procedures may be performed while on low-dose aspirin treatment. Except when bleeding may occur in closed spaces (e.g. intracranial surgery, spinal surgery in the medullary canal, surgery of the posterior chamber of the eye) or where excessive blood loss is expected, where only clopidogrel should be discontinued; in all other cases the surgical procedures should be carried out in the presence of dual antiplatelet agents (if prescribed). Aspirin may be discontinued only in subjects at low risk of thrombosis, and at high risk of intraoperative bleeding. Operations associated with an expected excessive blood loss should be postponed unless vital. When prescribed for acute coronary syndrome or during stent re-endothelialization, clopidogrel should not be discontinued before a noncardiac procedure. For elective procedures, surgery should be postponed until the end of the indication for clopidogrel. After the operation, clopidogrel should be resumed within the 12-24 h. Cardiac procedures should be postponed for at least 4 days after clopidogrel withdrawal. The thrombotic risk of preoperative withdrawal of antiplatelet drugs overwhelms the benefit of regional or neuraxial blockade. Antiplatelet treatment replacement by heparin or low-molecular weight heparin does not provide protection against the risk of coronary artery or stent thrombosis. Haemostasis requires that at least 20% of circulating platelets have a normal function. As the effects of antiplatelet agents are not reversible by other drugs, fresh platelets are the only manner to rapidly restore normal haemostasis. Aprotinin decreases postoperative bleeding and transfusion rates in patients undergoing CABG and on clopidogrel during the days preceding surgery.

Clinical and angiographic follow-up of small vessel lesions treated with paclitaxel-eluting stents (from the TRUE Registry)

Several randomized trials have shown that sirolimus-eluting stents and paclitaxel-eluting stents (PES) are effective in reducing restenosis in respect to bare-metal stents, including the subset of small vessels. The objective of this study was to evaluate "real world" angiographic and clinical outcomes of a large series of patients enrolled in the TRUE registry and treated with PES for both small vessel and very small vessel lesions. A consecutive series of 675 patients (926 lesions) with reference vessel diameter <2.75 mm measured by quantitative coronary angiography analysis were analyzed. The primary end point was the rate of angiographic in-stent restenosis and 1-year major adverse cardiac events. In this study 390 lesions were identified as small vessel (reference vessel diameter >or=2.25 and <2.75 mm) and 536 lesions as very small vessel (reference vessel diameter <2.25 mm). Overall in-stent restenosis was 15.5% (n = 96). Compared with small vessel, the very small vessel lesions had more in-stent restenosis (21.7% vs 11.4%, p <0.001) and in-segment restenosis (29.3% vs 22.5%, p = 0.055). The majority of the restenotic lesions (n = 125) were focal (57%, n = 71). At 1 year, cardiac death was 1.6% (n = 11), acute myocardial infarction 0.5% (n = 4.), and the target lesion revascularization 12.8% (n = 86). Cumulative major adverse cardiac events rate was 17.3% (n = 119). The rate of definite and probable stent thrombosis was 0.9% (n = 8). In conclusion, in comparison with historical bare-metal stent controls, this large series of small vessel lesions treated with PES confirms previous results reporting the efficacy of PES in small vessels. The rate of subacute and late stent thrombosis was low in this subgroup of patients.