Quantification of scientific output in cardiovascular medicine: a perspective based on global data

AIMS

We sought to explore whether global and regional scientific output in cardiovascular medicine is associated with economic variables and follows the same trend as medicine and as science overall.

METHODS AND RESULTS

We registered the number of documents, number of citations, citations per document and the h-index for the first 50 countries according to the h-index (a measure to evaluate both the productivity and impact of the publications) in cardiovascular medicine. Economic variables (gross domestic product [GDP] per capita, % expenditure of the GDP in research and development [R&D] and health) were obtained from the World Bank, the UNESCO, and the World Health Organization. In total, the scientific output in cardiology showed the same position as in medicine and science overall (mean difference vs. medicine -0.9±5.3º, p=0.25 vs. science -0.7±5.3º, p=0.39). We found significant correlations between the h-index and the % GDP expenditure in R&D (r=0.67, p<0.001), and the % GDP expenditure in health (r=0.71, p<0.0001). Overall, there was a 21.4% (interquartile range 3.7; 55.0) increase in the % GDP expenditure in R&D between 1996 and 2007. Emerging economies showed the larger growth in % GDP expenditure in health and R&D.

CONCLUSIONS

The global situation of scientific output in cardiovascular medicine is highly polarised and closely related to economic indicators. Emergent economies, with higher rates of GDP growth and increasingly larger expenditures for R&D and healthcare, are expected to show a visible escalation in the scientific global picture in the near future.

Vulnerable plaque: from bench to bedside; local pacification versus systemic therapy

Critical coronary stenoses accounts for a small proportion of acute coronary syndromes and sudden death. The majority are caused by coronary thromboses that arise from a nonangiographically obstructive atheroma. Recent developments in noninvasive imaging of so-called vulnerable plaques created opportunities to direct treatment to prevent morbidity and mortality associated with these high-risk lesions. This review covers therapy employed in the past, present, and potentially in the future as the natural history of plaque assessment unfolds.

Stent thrombosis and major clinical events at 3 years after zotarolimus-eluting or sirolimus-eluting coronary stent implantation: a randomised, multicentre, open-label, controlled trial

BACKGROUND

We sought to compare the long-term safety of two devices with different antiproliferative properties: the Endeavor zotarolimus-eluting stent (E-ZES; Medtronic, Inc) and the Cypher sirolimus-eluting stent (C-SES; Cordis, Johnson & Johnson) in a broad group of patients and lesions.

METHODS

Between May 21, 2007 and Dec 22, 2008, we recruited 8791 patients from 36 recruiting countries to participate in this open-label, multicentre, randomised, superiority trial. Eligible patients were those aged 18 years or older undergoing elective, unplanned, or emergency procedures in native coronary arteries. Patients were randomly assigned to either receive E-ZES and C-SES (ratio 1:1). Randomisation was stratified per centre with varying block sizes of four, six, or eight patients, and concealed with a central telephone-based or web-based allocation service. The primary outcome was definite or probable stent thrombosis at 3 years and was analysed by intention to treat. Patients and investigators were aware of treatment assignment. This trial is registered with ClinicalTrials.gov, number NCT00476957.

FINDINGS

PROTECT randomised 8791 patients, of whom 8709 provided consent to participate and were eligible: 4357 were allocated to the E-ZES group and 4352 patients to the C-SES group. At 3 years, rates of definite or probable stent thrombosis did not differ between groups (1·4% for E-ZES [predicted: 1·5%] vs 1·8% [predicted: 2·5%] for C-SES; hazard ratio [HR] 0·81, 95% CI 0·58-1·14, p=0·22). Dual antiplatelet therapy was used in 8402 (96%) patients at discharge, 7456 (88%) at 1 year, 3041 (37%) at 2 years, and 2364 (30%) at 3 years.

INTERPRETATION

No evidence of superiority of E-ZES compared with C-SES in definite or probable stent thrombosis rates was noted at 3 years. Time analysis suggests a difference in definite or probable stent thrombosis between groups is emerging over time, and a longer follow-up is therefore needed given the clinical relevance of stent thrombosis.

FUNDING

Medtronic, Inc.

Coronary plaque burden in patients with stable and unstable coronary artery disease using multislice CT coronary angiography

PURPOSE

We evaluated the multislice computed tomography (MSCT) coronary plaque burden in patients with stable and unstable angina pectoris.

MATERIALS AND METHODS

Twenty-one patients with stable and 20 with unstable angina pectoris scheduled for conventional coronary angiography (CCA) underwent MSCT-CA using a 64-slice scanner offering a fast rotation time (330 ms) and higher X-ray tube output (900 mAs). To determine the MSCT coronary plaque burden, we assessed the extent (number of diseased segments), size (small or large), type (calcific, noncalcific, mixed) of plaque, its anatomic distribution and angiographic appearance in all available ≥2-mm segments. In a subset of 15 (seven stable, eight unstable) patients, the detection and classification of coronary plaques by MSCT was verified by intracoronary ultrasound (ICUS).

RESULTS

Sensitivity and specificity of MSCT compared with ICUS to detect significant plaques (defined as ≥1-mm plaque thickness on ICUS) was 83% and 87%. Overall, 473 segments were examined, resulting in 11.6±1.5 segments per patient. Plaques were present in 62% of segments and classified as large in 47% of diseased segments. Thirty-two percent were noncalcific, 25% calcific and 43% mixed. Plaques were most frequently located in the proximal and mid segments. Plaque was found in 33% of segments classified as normal on CCA. Unstable patients had significantly more noncalcific plaques when compared with stable patients (45% vs. 21%, p<0.05).

CONCLUSIONS

MSCT-CA provides important information regarding the coronary plaque burden in patients with stable and unstable angina.

2-year follow-up of a randomized controlled trial of everolimus- and paclitaxel-eluting stents for coronary revascularization in daily practice. COMPARE (Comparison of the everolimus eluting XIENCE-V stent with the paclitaxel eluting TAXUS LIBERTÉ stent in all-comers: a randomized open label trial)

OBJECTIVES

The purpose of this study was to compare the safety and efficacy of the Xience V (Abbott Vascular, Santa Clara, California) everolimus-eluting stent (EES) with the Taxus Liberté (Boston Scientific, Natick, Massachusetts) paclitaxel-eluting stent (PES) at 2-year follow-up.

BACKGROUND

COMPARE (Comparison of the everolimus eluting XIENCE-V stent with the paclitaxel eluting TAXUS LIBERTÉ stent in all-comers: a randomized open label trial) demonstrated a superior clinical outcome of EES over PES at 1 year in all comers. Whether this superiority is maintained after discontinuation, at 12 months, of dual antiplatelet therapy is unclear.

METHODS

Patients undergoing percutaneous coronary intervention with limited exclusion criteria were randomly allocated to EES or PES. The 2-year pre-specified endpoints are composites of safety and efficacy and stent thrombosis.

RESULTS

Follow-up was completed in 1,795 of 1,800 patients (99.7%). The groups had similar baseline characteristics. At 2 years, significantly fewer EES patients took dual antiplatelet therapy (11.4% vs. 15.4%, p = 0.02). The primary composite of all death, nonfatal myocardial infarction, and target vessel revascularization occurred in 9.0% of EES patients and 13.7% of PES patients (relative risk [RR]: 0.66; 95% confidence interval [CI]: 0.50 to 0.86) driven by a lower rate of myocardial infarction (3.9% vs. 7.5%; RR: 0.52; 95% CI: 0.35 to 0.77) and target vessel revascularization (3.2% vs. 8.0%; RR: 0.41; 95% CI: 0.27 to 0.62), in parallel with a lower rate of definite or probable stent thrombosis (0.9% vs. 3.9%; RR: 0.23; 95% CI: 0.11 to 0.49). Differences significantly increased between 1- and 2-year follow-up for the primary composite endpoint (p = 0.04), target vessel revascularization (p = 0.02), and definite or probable stent thrombosis (p = 0.02).

CONCLUSIONS

The substantial clinical benefit of the EES over the PES with regard to measures of both safety and efficacy is maintained at 2 years in real-life practice with an increasing benefit in terms of safety and efficacy between 1 year and 2 years.

Enhancing back-up support during difficult coronary stent delivery: single-center case series of experience with the Heartrail II catheter

BACKGROUND

Despite continued advances in creating lower-profile intracoronary balloons and stents, technical difficulties with stent deliverability are frequently encountered. Recent advances in catheter design have yielded soft ended atraumatic catheters for use within standard guide catheters - the so called double coaxial guiding catheter technique. We report our preliminary experience using the 5 Fr Terumo guide catheter (Heartrail II, Terumo) from a single center.

METHODS

We describe six percutaneous coronary intervention (PCI) procedures where stent deployment initially failed during the standard approach. Subsequent utilization of this 5 Fr catheter system within a standard 6 Fr guide facilitated successful procedural outcomes. This catheter system facilitated non-traumatic deep intubation and stent delivery beyond the site of obstruction encountered during PCI of the distal right coronary and left anterior descending arteries.

RESULTS

3 males and 3 females with a mean age of 72.5 ± 5.4 years underwent PCI using the Heartrail II catheter. Patient and procedural characteristics are summarized in Table 1. The intracoronary catheter was inserted into 3 right coronary arteries, 2 left circumflex arteries and 1 left anterior descending artery. Classification of discrete lesions yielded 6 type C lesions. The mean number of stents deployed was 3.33 ± 0.80 with a mean procedure X-ray screening duration of 35.04 ± 7.79 minutes. No complications relating to ostial artery catheter-induced dissections were encountered.

Lumen enhancement influences absolute noncalcific plaque density on multislice computed tomography coronary angiography: ex-vivo validation and in-vivo demonstration

AIM

The purpose of this study was to define the in-vitro and in-vivo effects of intracoronary enhancement on the absolute density values of coronary plaques during multislice computed tomography.

METHODS

We studied seven ex-vivo left coronary artery specimens surrounded by olive oil and filled with isotonic saline and four solutions with decreasing dilutions of contrast material: control (isotonic saline), 1/200, 1/80, 1/50, and 1/20. The multislice computed tomography protocol was: slice/collimation 32 x 2 x 0.6 mm and rotation time 330 ms. The attenuation (Hounsfield units) value of atherosclerotic plaques was measured for each dilution in lumen, plaque (noncalcified coronary wall thickening), calcium, and surrounding oil. In-vivo assessment was performed in 12 patients (nine men; mean age 58.7 +/- 9.9 years) who underwent two subsequent multislice computed tomography scans (arterial and delayed) after intravenous administration of a single bolus of contrast material. The attenuation values of lumen and plaques during arterial and delayed computed tomography were compared. The results were compared with one-way analysis of variance and correlated with Pearson's test.

RESULTS

Mean lumen (45 +/- 38-669 +/- 151 HU) and plaque (11 +/- 35-101 +/- 72 HU) attenuation differed significantly (P < 0.001) among the different dilutions. The attenuation of lumen and plaque of coronary plaques showed moderate correlation (r = 0.54, P < 0.001). The mean attenuation value in vivo for the arterial and delayed phase scans differed significantly (P < 0.001) for lumen (325 +/- 70 and 174 +/- 46 HU, respectively) and plaque (138 +/- 71 and 100 +/- 52 HU, respectively).

CONCLUSION

Coronary plaque attenuation values are significantly modified by differences in lumen contrast densities both ex vivo and in vivo. This should be taken into account when considering the distinction between lipid and fibrous plaques.

Second-generation everolimus-eluting and paclitaxel-eluting stents in real-life practice (COMPARE): a randomised trial

BACKGROUND

Everolimus-eluting and paclitaxel-eluting stents, compared with bare metal stents, reduced the risk of restenosis in clinical trials with strict inclusion and exclusion criteria. We compared the safety and efficacy of the second-generation everolimus-eluting and paclitaxel-eluting stents in real-life practice.

METHODS

We randomly assigned 1800 consecutive patients (aged 18-85 years) undergoing percutaneous coronary intervention at one centre to treatment with everolimus-eluting or paclitaxel-eluting stents. The primary endpoint was a composite of safety and efficacy (all-cause mortality, myocardial infarction, and target vessel revascularisation) within 12 months. Patients were not told which stent they had been allocated. Analysis was by intention to treat. The trial is registered with ClinicalTrials.gov, number NCT01016041.

FINDINGS

Follow-up was completed in 1797 patients. The primary endpoint occurred in 56 (6%) of 897 patients in the everolimus-eluting stent group versus 82 (9%) of 903 in the paclitaxel-eluting stent group (relative risk 0.69 [95% CI 0.50-0.95], p value for superiority=0.02). The difference was attributable to a lower rate of stent thrombosis (6 [<1%] vs 23 [3%], 0.26 [0.11-0-64], p=0.002), myocardial infarction (25 [3%] vs 48 [5%], 0.52 [0.33-0.84], p=0.007), and target vessel revascularisation (21 [2%] vs 54 [6%], 0.39 [0.24-0.64], p=0.0001). Cardiac death, non-fatal myocardial infarction, or target lesion revascularisation occurred in 44 [5%] patients in the everolimus-eluting stent group versus 74 [8%] patients in the paclitaxel-eluting stent group, p value for superiority was 0.005.

INTERPRETATION

The everolimus-eluting stent is better than the second generation paclitaxel-eluting stent in unselected patients in terms of safety and efficacy. On the basis of our results, we suggest that paclitaxel-eluting stents should no longer be used in everyday clinical practice.

FUNDING

Unrestricted grants from Abbott Vascular and Boston Scientific.

Paclitaxel eluting stents for the treatment of angiographically non‐significant atherosclerotic lesions

OBJECTIVE

To assess the safety and efficacy of the implantation of Paclitaxel Eluting Stents (PES) for de novo, non-flow limiting lesions.

METHODS AND RESULTS

We assessed the 12-month occurrence of major adverse cardiac events (MACE) in 21 patients (4% of the total population treated in a 'real world' registry) with 22 non-significant coronary narrowings treated with PES. The following criteria had to be met: (1) the lesion was de novo; (2) the location was non-ostial, and not a bifurcation lesion; (3) the diameter stenosis by quantitative coronary angiography (QCA) was <50%; (4) there was no visible thrombus and (5) the lesion was not located in an angiographically diffusely diseased segment. Procedural success rate was 100% without any periprocedural myocardial infarction. After a mean follow-up of 407.33+/-53 (range: 344-498) days the overall MACE-free survival was 95.2%. Freedom from target revascularization was 95.2%.

CONCLUSIONS

The result of this non-randomized observational study suggests that the implantation of PES for de novo, non-significant lesions appears most probably safe and effective.

Ostial left main coronary stenosis in a frequent flyer

A 52 year old gentleman presented with chest pain, after a long distance flight from India; he had made long haul flights every 2 weeks over the last 5 years as part of his job. His ECG revealed T wave inversion in leads V1-3. Cardiac biomarkers including troponin were negative; we proceeded to exercise stress testing (EST). This revealed 2 mm ST depression at 2 min of the standard Bruce protocol, associated with chest pain. He was taken immediately to the coronary catheterization laboratory; engagement of the left main caused pressure damping with 6 French, then 5 French diagnostic Judkins left 4 catheters. An ostial left main stenosis was seen; the right and left coronary trees otherwise had no significant stenoses. He had normal LV function. He underwent inpatient CABG 7 days later.

Self-rated health does not explain the socioeconomic differential in mortality: a prospective study in the EPIC-Norfolk cohort

BACKGROUND

Self-rated health (SRH), a subjective measure of health, is strongly predictive of mortality, independently of objective measures of health status and existing known disease. There is a strong social gradient in SRH. An investigation was carried to determine whether SRH can explain the well-known socioeconomic gradient in mortality.

METHODS

The effect of adjusting for SRH on the socioeconomic differential in mortality was examined in a prospective study of 20 754 men and women aged 39-79 years, without prevalent disease, living in the general community in Norfolk, UK, recruited using general practice age-sex registers for 1993-1997 and followed up for an average of 10 years.

RESULTS

Mortality risk increased with decreasing social class in men and women. There was some attenuation after adjustment for covariates age, body mass index, smoking, history of diabetes, systolic blood pressure, cholesterol level, alcohol consumption, physical activity and educational level, but a gradient remained. Further adjustment for SRH attenuated the association slightly more, but there was still some evidence of a socioeconomic differential in mortality, particularly in class V compared with class I (age- and sex-adjusted hazard ratio 1.57; 95% CI 1.19 to 2.06).

CONCLUSIONS

SRH does not substantially explain the socioeconomic differential in mortality beyond that explained by health-related covariates.

Clinical end points in coronary stent trials: a case for standardized definitions

BACKGROUND

Although most clinical trials of coronary stents have measured nominally identical safety and effectiveness end points, differences in definitions and timing of assessment have created confusion in interpretation.

METHODS AND RESULTS

The Academic Research Consortium is an informal collaboration between academic research organizations in the United States and Europe. Two meetings, in Washington, DC, in January 2006 and in Dublin, Ireland, in June 2006, sponsored by the Academic Research Consortium and including representatives of the US Food and Drug Administration and all device manufacturers who were working with the Food and Drug Administration on drug-eluting stent clinical trial programs, were focused on consensus end point definitions for drug-eluting stent evaluations. The effort was pursued with the objective to establish consistency among end point definitions and provide consensus recommendations. On the basis of considerations from historical legacy to key pathophysiological mechanisms and relevance to clinical interpretability, criteria for assessment of death, myocardial infarction, repeat revascularization, and stent thrombosis were developed. The broadly based consensus end point definitions in this document may be usefully applied or recognized for regulatory and clinical trial purposes.

CONCLUSION

Although consensus criteria will inevitably include certain arbitrary features, consensus criteria for clinical end points provide consistency across studies that can facilitate the evaluation of safety and effectiveness of these devices.

Use of Impella Recover(R) LP 2.5 left ventricular assist device during high-risk percutaneous coronary interventions; clinical, haemodynamic and biochemical findings

AIM

To investigate in terms of clinical, haemodynamic and biochemical profile the safety and efficacy of the Impella Recover(R) LP 2.5 left ventricular assist device during elective high risk percutaneous coronary interventions (HR-PCI).

METHODS AND RESULTS

Ten out of twelve patients were initially enrolled to receive PCI supported by the Impella catheter; eight underwent pressure-volume (PV) loop analysis while one patient was monitored by intra-cardiac echocardiographic. Free haemoglobin (fHb), B-type natriuretic pepetide, catecholamines, aldosterone, angiotensin II, and endothelin were assessed before, every 40 minutes as average during the procedure and at 3, 12, 24 and 48 hours after intervention. The Impella catheter was used for 144+/-88 min [median (IQR) 108 (85-198)], and was removed immediately after the procedure in all but one patients. In 6, 3 and 2 patients, fHb levels increased above 1, 5 and 10 times the upper limit of normal (ULN), respectively. No significant effect was found on the tested biomarkers in Impella-supported procedures. The PV analysis showed the occurrence of an acute volume increase in the majority of patients immediately after Impella insertion that tended to persist even at maximal pump speed. This was confirmed by the intracardiac echocardiography that was performed in one patient.

CONCLUSIONS

Our data, although preliminary due to the limited sample size, does not encourage the routine use of Impella Recover(R) LP 2.5 in HR-PCI. Additional studies are required to confirm and elucidate the mechanisms responsible for the acute LV volume loading and to quantify the degree of haemolysis induced by the pump in a broader set of patients.

Methodological considerations and approach to cross-technique comparisons using in vivo coronary plaque characterization based on intravascular ultrasound radiofrequency data analysis: insights from the Integrated Biomarker and Imaging Study (IBIS)

Grey scale intravascular ultrasound (IVUS) is a valuable clinical tool to assess the extent and severity of coronary atheroma. However, it cannot reliably identify plaques with a high-risk of future clinical events. Serial IVUS studies to assess the progression and/or regression of atherosclerotic plaques demonstrated only modest effects, of pharmacological intervention on plaque burden, even when clinical efficacy is documented. Spectral analysis of radiofrequency ultrasound data (IVUS-virtual histology (IVUS-VH), Volcano Therapeutics, Rancho Cordova, CA) has the potential to characterize accurately plaque composition. The Integrated Biomarker and Imaging Study (IBIS) evaluated both invasive and non-invasive imaging techniques along with the assessment of novel biomarkers to characterize sub-clinical atherosclerosis. IVUS-VH was not included at the start of the IBIS protocol. The purpose of this paper is to describe the methodology we used to obtain and analyse IVUS-VH images and the approach to cross-correlations with the other techniques.

One-year clinical outcome after coronary stenting of very small vessels using 2.25 mm sirolimus- and paclitaxel-eluting stents: a comparison between the RESEARCH and T-SEARCH registries

BACKGROUND

The efficacy of sirolimus-eluting stents (SES) compared to paclitaxel-eluting stents (PES) remains unknown. We evaluated the clinical outcomes after implantation of 2.25 mm diameter SES and PES.

METHODS AND RESULTS

PES have been used as the stent of choice for all percutaneous coronary interventions as part of the prospective Taxus-Stent Evaluated At Rotterdam Cardiology Hospital (T-SEARCH) Registry. Ninety consecutive patients received at least one 2.25 mm PES (PES group), and were compared with 107 patients who received at least one 2.25 mm SES as part of the RESEARCH registry. The overall population presented high-risk characteristics commonly excluded from most studies. Populations were well-matched. There were 2 (2.2%) incidents of subacute stent thrombosis in the PES group (in a 2.25 mm stent), and none in the SES group. At one year, the cumulative incidence of major adverse cardiac events was 5.6% in the SES group, and 17.8% in the PES group (p = 0.007). After adjustments for other significant univariate variables, presentation with acute coronary syndrome (ACS) (adjusted OR 5.2 [95% CI 1.8-15.0], p = 0.002) and PES utilization (adjusted OR 3.7 [95% CI 1.3-10.5], p = 0.013) were found to be significant independent predictors of major adverse cardiac events (MACE).

CONCLUSIONS

In an unselected population treated for very small vessel disease, SES were associated with better 12-month clinical outcomes and the use of PES was identified as an independent predictor of adverse events.

Assessment of stent dimensions with a novel intracoronary balloon-based system: comparative study versus intravascular ultrasound and quantitative coronary angiography. The CAMUS - Coronary Angioplasty Metricath vs. UltraSound Trial

AIMS

To compare measurements of coronary stent dimensions using a novel, low pressure balloon catheter-based technique - Metricath (MC), with those obtained by intravascular ultrasound (IVUS) and quantitative coronary angiography (QCA).

BACKGROUND

Intravascular ultrasound (IVUS), the current gold standard to optimize stent placement is expensive, not widely available, and needs expertise for interpretation.

METHODS AND RESULTS

We compared cross-sectional diameter and area measurements obtained by MC, IVUS, and QCA immediately after successful stent implantation. The order of measurements was randomized. Both on-line and off-line (independent core lab) analysis was performed.Measurements were obtained in 21 patients at 22 stents in the LAD (n=10), RCA (n=6), and LCx (n=6). Nominal stent diameter was 2.5-3.5 mm. Average stent diameter was 2.54+/-0.28 mm by QCA, 2.77+/-0.31 mm by IVUS, and 2.86+/-0.28 mm by MC (P<0.001 QCA versus MC, P=0.13 IVUS versus MC). Results of on-line area measurements showed a small but significant difference between IVUS and MC 0.53 mm2, 95% confidence interval 0.17-0.90 mm2, P<0.01. Regression analysis demonstrated, however, that MC correlated best with off-line IVUS (diameter: y=1.01x, R2=0.83, P<0.001; area: y=1.02x, R2=0.81, P<0.001). Bland-Altman analysis showed a mean difference in diameter between on-line MC and off-line IVUS of 0.03+/-0.12 mm and between MC and off-line QCA of 0.10+/-0.23 mm.

CONCLUSION

MC is a new, promising method providing information on average stent dimensions that is equivalent to that obtained by off-line IVUS analyzed in an independent core lab.

Drug-eluting stent implantation for chronic total occlusions: comparison between the Sirolimus- and Paclitaxel-eluting stent

AIMS

Long-term results following percutaneous coronary intervention (PCI) with bare metal stents in the treatment of chronic total occlusions (CTOs) is hindered by a significant rate of restenosis and re-occlusion. Drug-eluting stents have shown dramatically reduced restenosis rates for the treatment of relatively simple non-occlusive lesions, though there is only limited data as to the efficacy in CTO's. We evaluated the long-term results of the sirolimus-eluting stent (SES) and paclitaxel-eluting stent (PES) for the treatment of CTOs.

METHODS AND RESULTS

From April 2002, all patients at our institution were treated with SES as the device of choice during PCI. During the first quarter of 2003 the default strategy changed to the use of PES. Drug-eluting stent implantation was carried out in CTOs (defined as >3 months' duration) in 9% of de novo PCI procedures. A total of 76 consecutive patients were treated with SES implantation, followed by a consecutive series of 57 patients treated with PES implantation. These patients were compared with a similar group of patients (n=26) treated with BMS in the 6-month period preceding April 2002. At 400 days, the cumulative survival-free of target vessel revascularization was 80.8% in the BMS group versus 97.4% and 96.4% in the SES and PES groups respectively (p=0.01).

CONCLUSIONS

The use of both the SES and PES in the treatment of chronic total coronary occlusions reduces the need for target vessel revascularization compared to bare metal stents.

Rationale and methods of the integrated biomarker and imaging study (IBIS): combining invasive and non-invasive imaging with biomarkers to detect subclinical atherosclerosis and assess coronary lesion biology

Death or myocardial infarction, the most serious clinical consequences of atherosclerosis, often result from plaque rupture at non-flow limiting lesions. Current diagnostic imaging with coronary angiography only detects large plaques that already impinge on the lumen and cannot accurately identify those that have a propensity to cause unheralded events. Accurate evaluation of the composition or of the biomechanical characteristics of plaques with invasive or non-invasive methods, alone or in conjunction with assessment of circulating biomarkers, could help identify high-risk patients, thus providing the rationale for aggressive treatments in order to reduce future clinical events. The IBIS (Integrated Biomarker and Imaging Study) study is a prospective, single-center, non-randomized, observational study conducted in Rotterdam. The aim of the IBIS study is to evaluate both invasive (quantitative coronary angiography, intravascular ultrasound (IVUS) and palpography) and non-invasive (multislice spiral computed tomography) imaging techniques to characterize non-flow limiting coronary lesions. In addition, multiple classical and novel biomarkers will be measured and their levels correlated with the results of the different imaging techniques. A minimum of 85 patients up to a maximum of 120 patients will be included. This paper describes the study protocol and methodological solutions that have been devised for the purpose of comparisons among several imaging modalities. It outlines the analyses that will be performed to compare invasive and non-invasive imaging techniques in conjunction with multiple biomarkers to characterize non-flow limiting subclinical coronary lesions.

The efficacy of sirolimus-eluting stents versus bare metal stents for diabetic patients undergoing elective percutaneous coronary intervention

BACKGROUND

Diabetes mellitus is a well-known risk factor for future adverse cardiac events after coronary intervention with conventional metal stents. In this study, the impact of sirolimus-eluting stents (SES) were evaluated in a consecutive group of diabetic patients undergoing elective percutaneous coronary treatment and compared to a population treated with bare metal stents.

METHODS AND RESULTS

From April 2002, a policy of routine SES implantation has been instituted in our hospital. During 1 year of enrollment, a total of 112 consecutive diabetic patients with de novo coronary lesions were electively treated with SES (SES group). A similar group for comparison comprised 118 consecutive patients treated with bare metal stents in the preceding period (the pre-SES group). After 1-year follow-up, the cumulative rate of major adverse cardiac events (death, myocardial infarction, and any repeat revascularization) was 17.3% in the SES group versus 30.2% in the pre-SES group (hazard ratio, 0.54 [95% confidence interval, 0.32-0.91]; p = 0.02), mainly due to a marked reduction in the need for repeat revascularization (10.2% versus 23.5%; hazard ratio, 0.40 [95% confidence interval, 0.21-0.78]; p = 0.007).

CONCLUSIONS

Routine utilization of SES for diabetic patients significantly reduces the rate of adverse cardiac events at 1 year compared to bare metal stents.

Coronary artery remodelling is related to plaque composition

OBJECTIVE

To assess the potential relation between plaque composition and vascular remodelling by using spectral analysis of intravascular ultrasound (IVUS) radiofrequency data.

METHODS AND RESULTS

41 coronary vessels with non-significant (< 50% diameter stenosis by angiography), < or = 20 mm, non-ostial lesions located in non-culprit vessels underwent IVUS interrogation. IVUS radiofrequency data obtained with a 30 MHz catheter, were analysed with IVUS virtual histology software. A remodelling index (RI) was calculated and divided into three groups. Lesions with RI > or = 1.05 were considered to have positive remodelling and lesions with RI < or = 0.95 were considered to have negative remodelling. Lesions with RI > or = 1.05 had a significantly larger lipid core than lesions with RI 0.96-1.04 and RI < or = 0.95 (22.1 (6.3) v 15.1 (7.6) v 6.6 (6.9), p < 0.0001). A positive correlation between lipid core and RI (r = 0.83, p < 0.0001) and an inverse correlation between fibrous tissue and RI (r = -0.45, p = 0.003) were also significant. All of the positively remodelled lesions were thin cap fibroatheroma or fibroatheromatous lesions, whereas negatively remodelled lesions had a more stable phenotype, with 64% having pathological intimal thickening, 29% being fibrocalcific lesions, and only 7% fibroatheromatous lesions (p < 0.0001).

CONCLUSIONS

In this study, in vivo plaque composition and morphology assessed by spectral analysis of IVUS radiofrequency data were related to coronary artery remodelling.