Impact of the first coronavirus-disease pandemic wave on cardiovascular admissions and sudden cardiac death rates in Greece

Background

Various studies suggest a decrease of hospital admissions for acute coronary syndromes (ACS) during COVID-19 outbreak, implying an increase in ACS related pre-hospital-care deaths as a cause of this phenomenon.

Purpose

Aim of this study was to investigate the impact of social containment measures on ACS admission and acute coronary deaths (ACDs) rates in Greece, during COVID-19 first pandemic wave in 2020.

Methods

Data for this analysis were retrieved by the official records of University Forensic and Cardiology Departments and the Forensic Science Services of the most crowded metropolitan areas of Greece (almost 25% of the entire Greek population ≈ 2.5 million people). The study period was defined as the time between March 15 2020, when the Greek state started to implement strict lock-down measures to contain COVID-19 pandemics, until April 14 2020. To compare admission and SCD rates, a corresponding control period a year earlier was chosen. Incidence rates (IRs) (events over days) of ACSs and ACDs in each time-period were assessed along with IRs ratios (IRRs) and 95% CI intervals. Secondary analysis for non-ischemic cardiovascular deaths (CVDs) or violent deaths (VDs) (including road traffic accident deaths) was also performed.

Results

There has been a relative 38.9% reduction in ACS admissions in 2020 [1.8, 95% CI (1.35–2.34) in 2019 vs 1.1, 95% CI (0.76–1.54) in 2020, p=0.02], concordant with a 66% relative reduction of total admissions (p<0.005). Overall, 171 deaths in 2020 vs 208 in 2019 were referred for autopsies in the enrolled forensic departments. Gender and age distribution were not significantly different between case and control periods. There were no statistically significant differences in the frequency of deaths between the two periods examined, with the exception of deaths secondary to road traffic accidents [IR 0.13, 95% CI (0.04–0.34) in 2020 vs 0.67, 95% CI (0.41–1.03) in 2019, p=0.001] and CVDs [IR 0.43, 95% CI (0.23–0.74) in 2020 vs 1.03, 95% CI (0.70–1.47) in 2019, p=0.007] which significantly decreased during COVID-19 pandemic wave. Absolute numbers, percentile changes and IRs are demonstrated in Figure 1 and Table 1.

Conclusions

Our analysis offers evidence over a significant decrease in ACS-related hospitalization rates during COVID-19 first pandemic wave. This decrease is not linked to an increase in pre-hospital, autopsy defined ACDs, as previously thought, implying that many ACS patients may not ask for help on time due to infection fear, being prone however to late-onset complications. Pre-hospital triage and care services, should be appropriately transformed to facilitate and speed-up access of cardiovascular patients to health-care systems during the pandemic.

Funding Acknowledgement

Type of funding sources: None. Figure 1

Shockwave intravascular lithotripsy facilitated percutaneous coronary intervention in patients with calcified coronary artery disease: a systematic review and meta-analysis of observational studies

Background

Percutaneous coronary intervention (PCI) outcomes for patients with significant coronary artery calcification (CAC) have been consistently inferior compared to patients without significant CAC. Shockwave Intravascular Lithotripsy (S-IVL) system offers a novel option for lesion modification of severely calcified plaques but supporting evidence on safety and efficacy of this technology is narrow. The aim of this study is to assess S-IVL safety and efficacy in patients with severe CAC undergoing PCI.

Methods

We systematically searched MEDLINE, ClinicalTrials.gov and the Cochrane Library to identify studies assessing the efficacy and safety of S-IVL in adult patients with calcified coronary artery disease undergoing PCI. We excluded those studies assessing the effect of S-IVL in patients with under-expanded coronary stents and/or in-stent restenosis.

Results

The largest meta-analysis to date was performed. All studies were observational since no relevant randomized controlled trials have been published so far. Nine studies were included in our qualitative synthesis, while 7 of them, in a total of 794 enrolled patients, were used in the quantitative synthesis. Frequency of peri-procedural outcomes of interest was low: a) coronary dissection: 2.52%, b) coronary perforation: 3.0%, c) MI: 3.51%. Relative frequency of 1-month MACE was 5.59% and cardiovascular death 1.01%. S-IVL resulted in a significant increase in the in-stent post-IVL minimum lumen diameter by 1.67 mm, a significant decrease in the in-stent post-IVL vessel diameter stenosis by 53.60%, and a significant increase in the in-stent post-IVL acute gain by 1.68 mm. OCT analysis confirmed a significant decrease in area stenosis post-IVL by 19.71% and calcium angle by 22.14o and a significant increase in lumen area by 1.62 mm2, without however affecting maximum calcium thickness. When we compared post-stent post-IVL vs. pre-stent post-IVL OCT results, we demonstrated a further significant decrease in area stenosis by 35.89% and in calcium angle by 20.33o, a significant increase in lumen area by 2.74 mm2 and a neutral effect on maximum calcium thickness.

Conclusion

Shockwave Intravascular lithotripsy offers a significant improvement in coronary lumen to facilitate stent delivery and deployment in severely calcified coronary arteries. Although S-IVL appears to be associated with a low incidence of complications and MACE based on our present findings, further evidence from RCTs and longer-term follow-up is required to advocate its routine use in patients with severe CAC.

Funding Acknowledgement

Type of funding sources: None.

Prognostic significance of novel serum biomarkers in patients with acute coronary syndrome

Background

As oxygen and nutrient supply to the myocardium significantly decrease during ischemic periods, important changes occur regarding myocardial intermediary energy metabolism and metabolomic biomarkers.

Purpose

To identify patients at high risk for adverse cardiovascular (CV) events based on their metabolic signatures through combining clinical characteristics with established and novel biomarkers. Hence, we investigated the prognostic significance of protein biomarkers associated with CAD, namely Galectin-3, Adiponectin, Neutrophil gelatinase-associated lipocalin (NGAL) and Apolipoprotein B and A-1 (ApoB and A-1).

Methods

We conducted a sub-analysis of the Corlipid trial (NCT04580173) including patients who underwent coronary angiography in the cardiac catheterization laboratory of an academic tertiary hospital. Venous fasting blood samples were collected prior to coronary angiography and patients were followed-up for 12 months to record the occurrence of major adverse CV events. Galectin-3, adiponectin, NGAL and ApoB/A-1 ratio were measured by enzyme-linked immunosorbent assay (ELISA) in patients' venous blood samples. Serum concentrations were compared among CAD patient subgroups to assess the prognostic significance of these novel protein biomarkers in terms of cardiovascular mortality. Receiver operating characteristic (ROC) curves were also performed to calculate the corresponding area under the curve (AUC) for each biomarker and define their prognostic validity for patients with CAD.

Results

Out of 1140 total participants of the CorLipid trial, 534 patients with acute coronary syndrome (ACS) were finally included in the present analysis. Of them, 222 suffered from STEMI, 170 from NSTEMI and 141 from unstable angina. Higher ApoB/ApoA-1 and Galectin-3 serum concentrations were significantly linked with higher incidence of CV death in patients with NSTEMI during the one-year study follow up (p=0.049 and 0.027, respectively). Generated AUC of 0.713 (p=0.047) and 0.775 (p=0.002) indicate a potential utility in the quantification of those proteins as predictors of CV death in patients with NSTEMI. Analysis of serum adiponectin values did not yield any significant outcome (p>0.05). Lower NGAL concentrations were significantly correlated with CV death in patients with STEMI (p<0.001). The corresponding AUC of 0.824 (p=0.003) demonstrated that NGAL could be a prognostic biomarker of great sensitivity and specificity, potently capable to identify STEMI patients with increased risk of CV mortality.

Conclusion(s)

In patients with ACS, higher values of serum ApoB/ApoA-I and Galectin-3, as well as low NGAL concentrations were associated with higher prevalence of CV death in specific patient subgroups. Therefore, these serum biomarkers could be utilized for early risk-stratification and a more individualized approach in patients with ACS. Larger trials are warranted to confirm and bolster the significance and generalizability of our findings.

Funding Acknowledgement

Type of funding sources: Public grant(s) – EU funding. Main funding source(s): The specific project has been co-financed through the call for Proposals for the Action “Competitiveness, entrepreneurship & innovation” in the framework of the Operational Programme “Research, Create, Innovate” (project code: T1EDK-04005) of the Partnership Agreement for the Development Programme 2014-2020 by the European Social Fund (ESF) and Greek National funds. The project has undergone peer review and has been approved for funding, being awarded a grant of €873,821.00. The funder had no role in the design or conduct of the study, preparation, review or approval of the manuscript and decision to submit the manuscript for publication.

568 Imaging and quantitative estimation of thrombus burden in patients with ST elevation acute myocardial infarction (STEMI) with the use of micro-computed tomography-A methodological approach

Funding Acknowledgements

Operational Program "Human Resources Development, Education and Lifelong Learning" - co-financed by the European Social Fund and Greek national funds

Background

Acute myocardial infarction with ST elevation (STEMI) remains one of the leading causes of mortality. High thrombus burden has been proven to be an independent risk factor for stent thrombosis and for Major Adverse Clinical outcomes. However randomized controlled trials concerning thrombus aspiration showed controversial results, providing no evidence of benefits for thrombus aspiration. A possible explanation is that aspiration was performed as a routine strategy, whereas these patients should be considered as a heterogeneous group and they should be risk-stratified. Thus, it is important to classify patients according to the volume of thrombus burden. The currently existing classifications of thrombus burden are based on visual assessment of angiographic characteristics and they are not reflecting the volume of the thrombi in actual numbers. To the best of our knowledge, never before has the exact volume of thrombus burden been quantified.

Purpose

The study aims to assess for the first time, through the application of innovative technologies (micro-Computed Tomography, micro-CT), important characteristics of aspirated thrombi (volume and density), which might be linked to certain clinical outcomes, in patients with STEMI.

Methodology

After being aspirated, thrombi are preserved in formalin. As they consist of soft tissue with low X-ray absorption, thrombi have to be stained using contrast enhancing chemicals prior to scanning; in particular a solution containing 0.3% phosphotungstic acid is used (Metscher protocol). The scanning procedure results into a series of projection images arranged in the form of image stacks which, in turn, are reformed in sections with the use of special software, which applies a modified algorithm of backward projection Feldkamp. The resulting sections are combined to create the 3D models which are further analyzed to extract useful measurements for the characteristics of the thrombi, such as volume and density.

Results

From January 2018 to May 2019, 66 patients were enrolled in the study. Mean age was 60.36 (±11.71) years and the majority of them (78.7%) were men. Revascularization was achieved in mean 358 ± 255 minutes from symptom onset. Distal embolization was observed in 27.5% of the patients and no-reflow phenomenon was seen in 11.6%. Angiographically evident residual thrombus burden was observed in 6 patients (8.7%). Micro-CT managed to effectively quantify the volume and the density of aspirated thrombi. Mean volume was 12.98 ± 10.84 mm3, mean density was 2992 ± 872 HU and mean surface was 0.206 ± 0.19.

Conclusion

Micro-CT can be used as a tool to effectively assess important characteristics of aspirated thrombi, which might be linked to certain clinical outcomes. This method could become the gold standard for the exact measurement of thrombus burden and could be used in larger, clinically-oriented trials to help stratify patients with thrombus burden according to their risk for adverse outcomes.

Abstract 568 Figure. Coronary thrombi as depicted on micro-CT

Inferoposterior myocardial infarction originating from an unexpected coronary vessel

Images

One year clinical follow up of paclitaxel eluting stents for acute myocardial infarction compared with sirolimus eluting stents

OBJECTIVE

To compare clinical outcome of paclitaxel eluting stents (PES) versus sirolimus eluting stents (SES) for the treatment of acute ST elevation myocardial infarction.

DESIGN AND PATIENTS

The first 136 consecutive patients treated exclusively with PES in the setting of primary percutaneous coronary intervention for acute myocardial infarction in this single centre registry were prospectively clinically assessed at 30 days and one year. They were compared with 186 consecutive patients treated exclusively with SES in the preceding period.

SETTING

Academic tertiary referral centre.

RESULTS

At 30 days, the rate of all cause mortality and reinfarction was similar between groups (6.5% v 6.6% for SES and PES, respectively, p = 1.0). A significant difference in target vessel revascularisation (TVR) was seen in favour of SES (1.1% v 5.1% for PES, p = 0.04). This was driven by stent thrombosis (n = 4), especially in the bifurcation stenting (n = 2). At one year, no significant differences were seen between groups, with no late thrombosis and 1.5% in-stent restenosis (needing TVR) in PES versus no reinterventions in SES (p = 0.2). One year survival free of major adverse cardiac events (MACE) was 90.2% for SES and 85% for PES (p = 0.16).

CONCLUSIONS

No significant differences were seen in MACE-free survival at one year between SES and PES for the treatment of acute myocardial infarction with very low rates of reintervention for restenosis. Bifurcation stenting in acute myocardial infarction should, if possible, be avoided because of the increased risk of stent thrombosis.

Long term outcome after intracoronary beta radiation therapy

OBJECTIVES

To determine the long term outcome after intracoronary beta radiation therapy (IRT).

SETTING

Tertiary referral centre.

METHODS

The rate of major adverse cardiac events (MACE) was retrospectively determined in 301 consecutive patients who were treated with IRT. MACE was defined as death, myocardial infarction, or any reintervention. Long term clinical outcome was obtained from an electronic database of hospital records and from questionnaires to the patients and referring physicians. Long term survival status was assessed by written inquiries to the municipal civil registries.

RESULTS

The mean (SD) follow up was 3.6 (1.2) years. The cumulative incidence of MACE at six months was 19.1%, at one year 36.4%, and at four years 58.3%. The target lesion revascularisation (TLR) rate at six months was 12.9%, at one year 28.3%, and at four years 50.4%. From multivariate analysis, dose < 18 Gy was the most significant predictor of TLR. At four years the cumulative incidence of death was 3.8%, of myocardial infarction 13.4%, and of coronary artery bypass surgery 11.3%. Total vessel occlusion was documented in 12.3% of the patients.

CONCLUSIONS

In the long term follow up of patients after IRT, there are increased adverse cardiac events beyond the first six months.

Routine sirolimus eluting stent implantation for unselected in-stent restenosis: insights from the rapamycin eluting stent evaluated at Rotterdam Cardiology Hospital (RESEARCH) registry

OBJECTIVE

To assess the effectiveness of routine sirolimus eluting stent (SES) implantation for unselected patients with in-stent restenosis and to provide preliminary information about the angiographic outcome for lesion subgroups and for different in-stent restenosis patterns.

DESIGN

Prospective, single centre registry.

SETTING

Tertiary referral centre.

PATIENTS

44 consecutive patients (53 lesions) without previous brachytherapy who were treated with SES for in-stent restenosis were evaluated. Routine angiographic follow up was obtained at six months and the incidence of major adverse cardiovascular events was evaluated.

RESULTS

At baseline, 42% of the lesions were focal, 21% diffuse, 26% proliferative, and 11% total occlusions. Small vessel size (reference diameter < or = 2.5 mm) was present in 49%, long lesions (> 20 mm) in 30%, treatment of bypass grafts in 13%, and bifurcation stenting in 18%. At follow up, post-SES restenosis was observed in 14.6%. No restenosis was observed in focal lesions. For more complex lesions, restenosis rates ranged from 20-25%. At the one year follow up, the incidence of death was 0, myocardial infarction 4.7% (n = 2), and target lesion revascularisation 16.3% (n = 7). The target lesion was revascularised because of restenosis in 11.6% (n = 5).

CONCLUSIONS

Routine SES implantation is highly effective for focal in-stent restenosis and appears to be a promising strategy for more complex patterns of restenosis.

Sonotherapy, antirestenotic therapeutic ultrasound in coronary arteries: the first clinical experience

We studied the safety and feasibility of intracoronary sonotherapy (IST) and its effect on the coronary vessel at 6 months. Thirty-seven patients with stable or unstable angina were included (40 lesions). The indication was de novo lesion (n = 26), restenosis (n = 2), in-stent restenosis (n = 11), and a total occlusion of a venous bypass graft. After successful angioplasty, IST was performed using a 5 Fr catheter with three serial ultrasound transducers operating at 1 MHz. IST was successfully performed in 36 lesions (success rate, 90%). IST exposure time per lesion was 718 +/- 127 sec. During hospital stay, one patient died due to a bleeding complication. At 6-month follow-up, one patient experienced acute myocardial infarction, eight patients underwent repeat PTCA. No patient underwent CABG. Late lumen loss was 1.05 +/- 0.70 mm with a restenosis rate of 25%. IVUS analysis revealed a neointima burden of 25% +/- 11%. IST can be applied safely and with high acute procedural success. Sonotherapy-related major adverse events were not observed. Late lumen loss and neointimal growth were similar to conventional PTCA approaches. These results justify the initiation of randomized clinical efficacy studies.

Intracoronary beta-radiation to reduce restenosis after balloon angioplasty and stenting; the Beta Radiation In Europe (BRIE) study

AIMS

The BRIE trial is a registry evaluating the safety and performance of (90)Sr delivered locally (Beta-Cath TM system of Novoste) to de-novo and restenotic lesions in patients with up to two discrete lesions in different vessels.

METHODS AND RESULTS

In total, 149 patients (175 lesions) were enrolled; 62 treated with balloons and 113 with stents. The restenosis rate, the minimal luminal diameter and the late loss were determined in three regions of interest: (a) in a subsegment of 5mm containing the original minimal luminal diameter pre-intervention termed target segment; (b) the irradiated segment, 28 mm in length, and (c) the entire analysed segment, 42 mm in length, termed the vessel segment. Binary restenosis was 9.9% for the target segment, 28.9% for the irradiated segment, and 33.6% for the vessel segment. These angiographic results include 5.3% total occlusions. Excluding total occlusions binary restenosis was 4.9%, 25% and 29.9%, respectively. At 1 year the incidence of major adverse cardiac events placed in a hierarchical ranking were: death 2%, myocardial infarction 10.1%, CABG 2%, and target vessel revascularization 20.1%. The event-free survival rate was 65.8%. Non-appropriate coverage of the injured segment by the radioactive source termed geographical miss affected 67.9% of the vessels, and increased edge restenosis significantly (16.3% vs 4.3%, P=0.004). It accounted for 40% of the treatment failures.

CONCLUSION

The results of this registry reflect the learning process of the practitioner. The full therapeutic potential of this new technology is reflected by the restenosis rate at the site of the target segment. It can only be unravelled once the incidence of late vessel occlusion and geographical miss has been eliminated by the prolonged use of thienopyridine, the appropriate training of the operator applying this new treatment for restenosis prevention, and the use of longer sources.

Routine intracoronary beta-irradiation. Acute and one year outcome in patients at high risk for recurrence of stenosis

AIMS

Intracoronary radiation is a promising therapy potentially reducing restenosis following catheter-based interventions. Currently, only limited data on this treatment are available. The feasibility and outcome in daily routine practice, however, is unknown.

METHODS AND RESULTS

In 100 consecutive patients, intracoronary beta-radiation was performed with a (90)Strontium system (Novoste Beta-Cathtrade mark) following angioplasty. Predominantly complex (73% type B2 and C) and long lesions (length 24.3+/-15.3 mm) were included (37% de novo, 19% restenotic and 44% in-stent restenotic lesions). Radiation success was 100%. Mean prescribed dose was 19.8+/-2.5 Gy. A pullback procedure was performed in 19% lesions. Geographic miss occurred in 8% lesions. Periprocedural thrombus formation occurred in four lesions, dissection in nine lesions. During hospital stay, no death, acute myocardial infarction, or repeat revascularization was observed. Major adverse cardiac events occurred predominantly between 6 and 12 months after the index procedure with major adverse cardiac event-free survival of 66% at 12 months (one death, 10 Q-wave myocardial infarctions, 23 target vessel revascularizations; ranked for worst event).

CONCLUSION

Routine catheter-based intracoronary beta-radiation therapy after angioplasty is safe and feasible with a high acute procedural success. The clinical 1-year follow-up showed delayed occurrence of major adverse cardiac events between 6 and 12 months after the index procedure.

In vitro study of FFR, QCA, and IVUS for the assessment of optimal stent deployment

We tested whether fractional flow reserve (FFR) discriminates between suboptimally and optimally deployed stents. Latex tubes (diameter solidus in circle = 4 mm) with diameter stenosis 40% (n = 3), 50% (n = 3) and 60% (n = 3) were tested in a pulsatile flow system, using water. Measurements were done at baseline (n = 9; FFR/QCA) and after suboptimal (SOD; 3-mm balloon at 8 atm) and optimal (OD; 4 mm balloon at 16 atm) deployment of a 35-mm stent (n = 6; FFR/QCA/IVUS). Varying Q from 150 to 50 ml/min increased FFR by 2-7%. Conversely, at 100 ml/min, FFR increased by only 0.8% from SOD to OD (P < 0.05). Extrapolating data to blood flow, the gain in FFR from SOD to OD is less than 5% for Q = 100 ml/min, while FFR may increase by 15-20% by changes in blood flow from 50 to 150 ml/min. We conclude that IVUS and QCA are more appropriate for the assessment of optimal stent deployment.

Evaluation of left ventricular function and volumes in patients with ischaemic cardiomyopathy: gated single-photon emission computed tomography versus two-dimensional echocardiography

The objective of this study was to perform a head-to-head comparison between two-dimensional (2D) echocardiography and gated single-photon emission computed tomography (SPET) for the evaluation of left ventricular (LV) function and volumes in patients with severe ischaemic LV dysfunction. Thirty-two patients with chronic ischaemic LV dysfunction [mean LV ejection fraction (EF) 25%+/-6%] were studied with gated SPET and 2D echocardiography. Regional wall motion was evaluated by both modalities and scored by two independent observers using a 16-segment model with a 5-point scoring system (1= normokinesia, 2= mild hypokinesia, 3= severe hypokinesia, 4= akinesia and 5= dyskinesia). LVEF and LV end-diastolic and end-systolic volumes were evaluated by 2D echocardiography using the Simpson's biplane discs method. The same parameters were calculated using quantitative gated SPET software (QGS, Cedars-Sinai Medical Center). The overall agreement between the two imaging modalities for assessment of regional wall motion was 69%. The correlations between gated SPET and 2D echocardiography for the assessment of end-diastolic and end-systolic volumes were excellent (r=0.94, P<0.01, and r=0.96, P<0.01, respectively). The correlation for LVEF was also good (r=0.83, P<0.01).

IN CONCLUSION

in patients with ischaemic cardiomyopathy, close and significant relations between gated SPET and 2D echocardiography were observed for the assessment of regional and global LV function and LV volumes; gated SPET has the advantage that it provides information on both LV function/dimensions and perfusion.

Uncomplicated moderate coronary artery dissections after balloon angioplasty: good outcome without stenting

OBJECTIVE

To study the relation between moderate coronary dissections, coronary flow velocity reserve (CFVR), and long term outcome.

METHODS

523 patients undergoing balloon angioplasty and sequential intracoronary Doppler measurements were examined as part of the DEBATE II trial (Doppler endpoints balloon angioplasty trial Europe). After successful balloon angioplasty, patients were randomised to stenting or no further treatment. Dissections were graded at the core laboratory by two observers and divided into four categories: none, mild (type A-B), moderate (type C), severe (types D to F). Patients with severe dissections (n = 128) or without available reference vessel CFVR (n = 139) were excluded. The remaining 256 patients were divided into two groups according to the presence (group A, n = 45) or absence (group B, n = 211) of moderate dissection.

RESULTS

Following balloon angioplasty, there was no difference in CFVR between the two groups. At 12 months follow up, a higher rate of major adverse cardiac events was observed overall in group A than in group B (10 (22%)v 23 (11%), p = 0.041). However, the risk of major adverse events was similar in the subgroups receiving balloon angioplasty (group A, 6 (19%) v group B, 16 (16%), NS). Among group A patients, the adverse events risk was greater in those randomised to stenting (odds ratios 6.603v 1.197, p = 0.046), whereas there was no difference in risk if the group was analysed according to whether the CFVR was < 2.5 or ⩾ 2.5 after balloon angioplasty.

CONCLUSIONS

Moderate dissections left untreated result in no increased risk of major adverse cardiac events. Additional stenting does not improve the long term outcome.

Uncomplicated moderate coronary artery dissections after balloon angioplasty: good outcome without stenting

OBJECTIVE

To study the relation between moderate coronary dissections, coronary flow velocity reserve (CFVR), and long term outcome.

METHODS

523 patients undergoing balloon angioplasty and sequential intracoronary Doppler measurements were examined as part of the DEBATE II trial (Doppler endpoints balloon angioplasty trial Europe). After successful balloon angioplasty, patients were randomised to stenting or no further treatment. Dissections were graded at the core laboratory by two observers and divided into four categories: none, mild (type A-B), moderate (type C), severe (types D to F). Patients with severe dissections (n = 128) or without available reference vessel CFVR (n = 139) were excluded. The remaining 256 patients were divided into two groups according to the presence (group A, n = 45) or absence (group B, n = 211) of moderate dissection.

RESULTS

Following balloon angioplasty, there was no difference in CFVR between the two groups. At 12 months follow up, a higher rate of major adverse cardiac events was observed overall in group A than in group B (10 (22%) v 23 (11%), p = 0.041). However, the risk of major adverse events was similar in the subgroups receiving balloon angioplasty (group A, 6 (19%) v group B, 16 (16%), NS). Among group A patients, the adverse events risk was greater in those randomised to stenting (odds ratios 6.603 v 1.197, p = 0.046), whereas there was no difference in risk if the group was analysed according to whether the CFVR was < 2.5 or >/= 2.5 after balloon angioplasty.

CONCLUSIONS

Moderate dissections left untreated result in no increased risk of major adverse cardiac events. Additional stenting does not improve the long term outcome.

Geographical miss during catheter-based intracoronary beta-radiation: incidence and implications in the BRIE study. Beta-Radiation In Europe

OBJECTIVES

We sought to determine the incidence and causes of geographical miss (GM) and to evaluate its impact on edge restenosis after intracoronary beta-radiation therapy.

BACKGROUND

Edge restenosis is a limitation of intracoronary beta-radiation therapy. Geographical miss is the situation in which the radiation source does not fully cover the injured segment and may lead to edge restenosis.

METHODS

We analyzed 175 vessels treated according to the Beta-Radiation In Europe (BRIE) study protocol. The effective irradiated segment (EIRS) and both edges were studied with quantitative coronary angiography. The edges of the EIRS that were injured constituted the GM edges. Restenosis was defined as diameter stenosis >50% at follow-up. Geographical miss was determined by simultaneous electrocardiographic-matched, side-by-side projection of the source and balloons deflated at the injury site, in identical angiographic projections surrounded by contrast.

RESULTS

Geographical miss affected 41.2% of the edges and increased edge restenosis significantly compared with non-GM edges (16.3% vs. 4.3%, respectively, p = 0.004). Restenosis was increased both in the proximal (p = 0.05) and distal (p = 0.02) GM edges compared with noninjured edges. Geographical miss associated with stent injury significantly increased edge restenosis (p = 0.006), whereas GM related to balloon injury did not significantly increase edge restenosis (p = 0.35). The restenosis in the EIRS was similar between vessels with and without GM (24.3% and 21.6%, respectively, p = 0.8).

CONCLUSIONS

Geographical miss is strongly associated with restenosis at the edges of the EIRS. This effect is more prominent when caused by stenting. Geographical miss does not increase restenosis in the EIRS.

The pattern of restenosis and vascular remodelling after cold-end radioactive stent implantation

BACKGROUND

Edge restenosis is a major problem after radioactive stenting. The cold-end stent has a radioactive mid-segment (15.9 mm) and non-radioactive proximal and distal 5.7 mm segments. Conceptually this may negate the impact of negative vascular remodelling at the edge of the radiation.

METHOD AND RESULTS

ECG-gated intravascular ultrasound with three-dimensional reconstruction was performed post-stent implantation and at the 6-month follow-up to assess restenosis within the margins of the stent and at the stent edges in 16 patients. Angiographic restenosis was witnessed in four patients, all in the proximal in-stent position. By intravascular ultrasound in-stent neointimal hyperplasia, with a >50% stented cross-sectional area, was seen in eight patients. This was witnessed proximally (n=2), distally (n=2) and in both segments (n=4). Echolucent tissue, dubbed the 'black hole' was seen as a significant component of neointimal hyperplasia in six out of the eight cases of restenosis. Neointimal hyperplasia was inhibited in the area of radiation: Delta neointimal hyperplasia=3.72 mm3 (8.6%); in-stent at the edges of radiation proximally and distally Delta neointimal hyperplasia was 7.9 mm3 (19.0%) and 11.4 mm3 (25.6%), respectively (P=0.017). At the stent edges there was no significant change in lumen volume.

CONCLUSIONS

Cold-end stenting results in increased neointimal hyperplasia in in-stent non-radioactive segments.

Value of coronary stenotic flow velocity acceleration on the prediction of long-term improvement in functional status after angioplasty

BACKGROUND

The coronary flow velocity acceleration at the stenotic site (SVA), defined as a > or = 50% increase in resting stenotic velocity when compared with the reference segment, has been shown to be highly sensitive and specific for the diagnosis of a hemodynamically significant stenosis. In this study, we describe the value of postprocedural SVA for the prediction of a lack of improvement in functional activity at long-term follow-up balloon angioplasty (BA).

METHODS

We investigated the improvement in functional activity in patients undergoing single native vessel angioplasty and intracoronary Doppler (before BA, after BA, and again at 6-month follow-up) as part of the Doppler Endpoints Balloon Angioplasty Trial Europe (DEBATE) I trial. Lack of improvement was defined as no change in Duke Activity Status Index (DASI) at 6-month follow-up, whereas SVA was defined as > or = 50% elevation in resting velocity at the treated area compared with the distal measurement.

RESULTS

SVA was found more frequently in patients without improvement in DASI (45% vs 31%, P =.03). Similar percent diameter stenosis and coronary flow velocity reserve were observed in patients with and those without improvement in DASI at follow-up. By multivariate regression analysis, the presence of SVA (P = .029; odds ratio, 1.97; 95% confidence interval, 1.07 to 3.63) and an elevated DASI at baseline (P < .001; odds ratio, 1.05; 95% confidence interval, 1.03 to 1.07) were associated with a lack of improvement at follow-up.

CONCLUSIONS

The detection of SVA was associated with failure of improvement in functional activity at follow-up after coronary intervention.

Radioactive stents delay but do not prevent in-stent neointimal hyperplasia

BACKGROUND

Restenosis after conventional stenting is almost exclusively caused by neointimal hyperplasia. Beta-particle-emitting radioactive stents decrease in-stent neointimal hyperplasia at 6-month follow-up. The purpose of this study was to evaluate the 1-year outcome of (32)P radioactive stents with an initial activity of 6 to 12 microCi using serial quantitative coronary angiography and volumetric ECG-gated 3D intravascular ultrasound (IVUS).

METHODS AND RESULTS

Of 40 patients undergoing initial stent implantation, 26 were event-free after the 6-month follow-up period and 22 underwent repeat catheterization and IVUS at 1 year; they comprised half of the study population. Significant luminal deterioration was observed within the stents between 6 months and 1 year, as evidenced by a decrease in the angiographic minimum lumen diameter (-0.43+/-0.56 mm; P:=0.028) and in the mean lumen diameter in the stent (-0.55+/-0. 63 mm; P:=0.001); a significant increase in in-stent neointimal hyperplasia by IVUS (18.16+/-12.59 mm(3) at 6 months to 27.75+/-11. 99 mm(3) at 1 year; P:=0.001) was also observed. Target vessel revascularization was performed in 5 patients (23%). No patient experienced late occlusion, myocardial infarction, or death. By 1 year, 21 of the initial 40 patients (65%) remained event-free.

CONCLUSIONS

Neointimal proliferation is delayed rather than prevented by radioactive stent implantation. Clinical outcome 1 year after the implantation of stents with an initial activity of 6 to 12 microCi is not favorable when compared with conventional stenting.

Stent development and local drug delivery

Stent implantation has become the new standard angioplasty procedure. In-stent re-stenosis remains the major limitation of coronary stenting. Re-stenosis is related to patient-, lesion- and procedure-specific factors. Patient-specific factors can not be influenced to any extent. Procedure-specific factors are affected by implantation technique and stent characteristics. Design and material influence vascular injury and humoral and cellular response. Radiation has been shown to have inhibitory effects on smooth muscle cell growth and neo-intima formation, but in clinical trials the outcome has been hampered by re-stenosis at the edges of the radioactive stent ('candy wrapper'). New approaches target pharmacological modulation of local vascular biology by local administration of drugs. This allows for drug application at the precise site and time of vessel injury. Systemic release is minimal and this may reduce the risk of toxicity. The drug and the delivery vehicle must fulfil pharmacological, pharmacokinetic and mechanical requirements and the application of eluting degradable matrices seems to be a possible solution. Numerous pharmacological agents with antiproliferative properties are currently under clinical investigation, e.g. actinomycin D, rapamycin or paclitaxel. Another approach is for stents to be made of biodegradable materials as an alternative to metallic stents. Their potential long-term complications, such as in-stent re-stenosis and the inaccessibility of the lesion site for surgical revascularization, needs to be assessed. Current investigational devices and the line of (pre)clinical investigation are discussed in detail. Currently, there is little experimental, and only preliminary clinical, understanding of the acute and long-term effects of drug-eluting or biodegradable stents in coronary arteries. The clinical benefit of these approaches still has to be proven.