Angiographic Disease Progression and Residual Risk of Cardiovascular Events While on Optimal Medical Therapy

Comparison of Characteristics and Outcomes of Veterans With Stable Ischemic Heart Disease Enrolled in the COURAGE Trial Versus the Veterans Affairs Clinical Assessment, Reporting, and Tracking Program

Randomized clinical trials have not demonstrated a survival benefit with percutaneous coronary intervention in stable ischemic heart disease (SIHD). We evaluated the generalizability of the COURAGE (Clinical Outcomes Utilizing Revascularization and Aggressive Drug Evaluation) trial findings to the broader population of veterans with SIHD. Veterans who underwent coronary angiography between 2005 and 2013 for SIHD were identified from the Veterans Affairs Clinical Assessment, Reporting and Tracking Program (VA CART). Patient-level comparisons were made between patients from VA CART who met the eligibility criteria for COURAGE and veterans enrolled in COURAGE between 1999 and 2004. All-cause mortality over long-term follow-up was assessed using Cox proportional hazards models. COURAGE-eligible patients from VA CART (n = 59,758) were older, had a higher body mass index, a greater prevalence of co-morbidities, but fewer diseased vessels on index coronary angiography, and were less likely to be on optimal medical therapy at baseline and on 1-year follow-up compared with VA COURAGE participants (n = 968). Patients from VA CART (median follow-up 6.5 years) had higher all-cause mortality (adjusted hazard ratio [aHR] 1.98 [1.61 to 2.43]) than participants from VA COURAGE (median follow-up: 4.6 years). Risks of mortality were greater in the 56.4% patients from CART who were medically managed (aHR 1.94 [1.49 to 2.53]) and in the 43.6% who underwent percutaneous coronary intervention (aHR 1.99 [1.45 to 2.74]), compared with their respective VA COURAGE arms. In conclusion, in this noncontemporaneous patient-level analysis, veterans in the randomized COURAGE trial had more favorable outcomes than the population of veterans with SIHD at large.

Individual Patient Data Meta-analysis of Drug-eluting Versus Bare-metal Stents for Percutaneous Coronary Intervention in Chronic Versus Acute Coronary Syndromes

New-generation drug-eluting stents (DES) strongly reduce restenosis and repeat revascularization compared with bare-metal stents (BMS) for percutaneous coronary intervention. There is residual uncertainty as to whether other prognostically relevant outcomes are affected by DES versus BMS concerning initial presentation (chronic coronary syndrome [CCS] vs acute coronary syndrome [ACS]). We performed an individual patient data meta-analysis of randomized trials comparing new-generation DES versus BMS (CRD42017060520). The primary outcome was the composite of cardiac death or myocardial infarction (MI). Outcomes were examined at maximum follow-up and with a 1-year landmark. Risk estimates are expressed as hazard ratio (HR) with 95% confidence interval (CI). A total of 22,319 patients were included across 14 trials; 7,691 patients (34.5%) with CCS and 14,628 patients (65.5%) with ACS. We found evidence that new-generation DES versus BMS consistently reduced the risk of cardiac death or MI in both patients with CCS (HR 0.83, 95% CI 0.70 to 0.98, p <0.001) and ACS (HR 0.83, 95% CI 0.75 to 0.92, p <0.001) (p-interaction = 0.931). This benefit was mainly driven by a similar reduction in the risk of MI (p-interaction = 0.898) for both subsets (HR_CCS 0.80, 95% CI 0.65 to 0.97; HR_ACS 0.79, 95% CI 0.70 to 0.89). In CCS and ACS, we found a time-dependent treatment effect, with the benefit from DES accumulating during 1-year follow-up, without offsetting effects after that. In conclusion, patients with CCS were slightly underrepresented in comparative clinical trials. Still, they benefited similarly to patients with ACS from new-generation DES instead of BMS with a sustained reduction of cardiac death or MI because of lower event rates within 1 year.

Quantitative plaque characterisation and association with acute coronary syndrome on medium to long term follow up: insights from computed tomography coronary angiography

Background

Computed tomography coronary angiography (CTCA) is an established imaging modality widely used for diagnosing coronary artery stenosis with expanding potential for comprehensive assessment of coronary artery disease (CAD). Lesion-based analyses of high-risk plaques (HRP) on CTCA may aid further in prognostication presenting with stable chest pain. We conduct qualitative and quantitative assessments to identify HRPs that are associated with acute coronary syndrome (ACS) on a medium to long term follow-up.

Methods

Retrospective cohort study of patients who underwent CTCA for suspected CAD. Obstructive stenosis (OS) is defined as ≥50% and the presence of HRP and its constituents: positive-remodelling (PR), low-attenuation-plaque (LAP; <56 HU), very-low-attenuation-plaque (vLAP; <30 HU) and spotty-calcification (SC) were recorded. A cross-sectional quantitative analysis of HRP was performed at the site of minimum-luminal-area (MLA). The primary endpoint was fatal or non-fatal ACS on follow-up.

Results

A total of 1,257 patients were included (mean age 61±14 years old and 51% male) with a median follow-up of 7.24 years (interquartile range 5.5 to 7.7 years). The occurrence of ACS was significantly higher in HRP (+) patients compared to HRP (−) patients and patients with no plaques (20.5% vs. 1.6% vs. 0.4%, log-rank test P<0.001). ACS was more frequent in HRP (+)/OS (+) patients (20.7%) compared to HRP (+)/OS (−) patients (8.6%), HRP (−)/OS (+) patients (1.8%) and HRP (−)/OS (−) patients (1.0%). OS, cross-sectional plaque area (PA) and the presence of vLAP identified those HRP lesions that were more likely to cause future ACS. Cross-sectional LAP area (<56 HU) in HRP lesions added incremental prognostic value to OS in predicting ACS (P=0.008).

Conclusions

The presence of OS and the LAP area at the site of MLA identify the HRP lesions that have the greatest association with development of future ACS.

Anatomic and Flow Characteristics of Left Anterior Descending Coronary Artery Angiographic Stenoses Predisposing to Myocardial Infarction

The impact of the anatomic characteristics of coronary stenoses on the development of future coronary thrombosis has been controversial. This study aimed at identifying the anatomic and flow characteristics of left anterior descending (LAD) coronary artery stenoses that predispose to myocardial infarction, by examining angiograms obtained before the index event. We identified 90 patients with anterior ST-elevation myocardial infarction (STEMI) for whom coronary angiograms and their reconstruction in the three-dimensional space were available at 6 to 12 months before the STEMI, and at the revascularization procedure. The majority of culprit lesions responsible for STEMI occurred between 20 and 40 mm from the LAD ostium, whereas the majority of stable lesions not associated with STEMI were found in distances >60 mm (p < 0.001). Culprit lesions were significantly more stenosed (diameter stenosis 68.6 ± 14.2% vs 44.0 ± 10.4%, p < 0.001), and significantly longer than stable ones (15.3 ± 5.4 mm vs 9.2 ± 2.5 mm, p < 0.001). Bifurcations at culprit lesions were significantly more frequent (88.8%) compared with stable lesions (34.4%, p < 0.001). Computational fluid dynamics simulations demonstrated that hemodynamic conditions in the vicinity of culprit lesions promote coronary thrombosis due to flow recirculation. A multiple logistic regression model with diameter stenosis, lesion length, distance from the LAD ostium, distance from bifurcation, and lesion symmetry, showed excellent accuracy in predicting the development of a culprit lesion (AUC: 0.993 [95% CI: 0.969 to 1.000], p < 0.0001). In conclusion, specific anatomic and hemodynamic characteristics of LAD stenoses identified on coronary angiograms may assist risk stratification of patients by predicting sites of future myocardial infarction.

Comparison of coronary atherosclerotic disease burden between ST-elevation myocardial infarction and non-ST-elevation myocardial infarction: Non-culprit Gensini score and non-culprit SYNTAX score

Background

Patients with non‐ST‐elevation myocardial infarction (NSTEMI) have worse long‐term prognoses than those with ST‐elevation myocardial infarction (STEMI).

Hypothesis

It may be attributable to more extended coronary atherosclerotic disease burden in patients with NSTEMI.

Methods

This study consisted of consecutive 231 patients who underwent coronary intervention for myocardial infarction (MI). To assess the extent and severity of atherosclerotic disease burden of non‐culprit coronary arteries, two scoring systems (Gensini score and synergy between percutaneous coronary intervention with Taxus and cardiac surgery [SYNTAX] score) were modified by subtracting the score of the culprit lesion: the non‐culprit Gensini score and the non‐culprit SYNTAX score.

Results

Patients with NSTEMI had more multi‐vessel disease, initial thrombolysis in myocardial infarction (TIMI) flow grade 2/3, and final TIMI flow grade 3 than those with STEMI. As compared to STEMI, patients with NSTEMI had significantly higher non‐culprit Gensini score (16.3 ± 19.8 vs. 31.2 ± 25.4, p < 0.001) and non‐culprit SYNTAX score (5.8 ± 7.0 vs. 11.1 ± 9.7, p < 0.001).

Conclusions

Patients with NSTEMI had more advanced coronary atherosclerotic disease burden including non‐obstruction lesions, which may at least in part explain higher incidence of cardiovascular events in these patients.

Use of High-Risk Coronary Atherosclerotic Plaque Detection for Risk Stratification of Patients With Stable Chest Pain: A Secondary Analysis of the PROMISE Randomized Clinical Trial

Importance

Coronary computed tomographic angiography (coronary CTA) can characterize coronary artery disease, including high-risk plaque. A noninvasive method of identifying high-risk plaque before major adverse cardiovascular events (MACE) could provide practice-changing optimizations in coronary artery disease care.

Objective

To determine whether high-risk plaque detected by coronary CTA was associated with incident MACE independently of significant stenosis (SS) and cardiovascular risk factors.

Design, Setting, and Participants

This prespecified nested observational cohort study was part of the Prospective Multicenter Imaging Study for Evaluation of Chest Pain (PROMISE) trial. All stable, symptomatic outpatients in this trial who required noninvasive cardiovascular testing and received coronary CTA were included and followed up for a median of 25 months.

Exposures

Core laboratory assessment of coronary CTA for SS and high-risk plaque (eg, positive remodeling, low computed tomographic attenuation, or napkin-ring sign).

Main Outcomes and Measures

The primary end point was an adjudicated composite of MACE (defined as death, myocardial infarction, or unstable angina).

Results

The study included 4415 patients, of whom 2296 (52%) were women, with a mean age of 60.5 years, a median atherosclerotic cardiovascular disease (ASCVD) risk score of 11, and a MACE rate of 3% (131 events). A total of 676 patients (15.3%) had high-risk plaques, and 276 (6.3%) had SS. The presence of high-risk plaque was associated with a higher MACE rate (6.4% vs 2.4%; hazard ratio, 2.73; 95% CI, 1.89-3.93). This association persisted after adjustment for ASCVD risk score and SS (adjusted hazard ratio [aHR], 1.72; 95% CI, 1.13-2.62). Adding high-risk plaque to the ASCVD risk score and SS assessment led to a significant continuous net reclassification improvement (0.34; 95% CI, 0.02-0.51). Presence of high-risk plaque increased MACE risk among patients with nonobstructive coronary artery disease relative to patients without high-risk plaque (aHR, 4.31 vs 2.64; 95% CI, 2.25-8.26 vs 1.49-4.69). There were no significant differences in MACE in patients with SS and high-risk plaque as opposed to those with SS but not high-risk plaque (aHR, 8.68 vs. 9.31; 95% CI, 4.25-17.73 vs 4.21-20.61). High-risk plaque was a stronger predictor of MACE in women (aHR, 2.41; 95% CI, 1.25-4.64) vs men (aHR, 1.40; 95% CI, 0.81-2.39) and younger patients (aHR, 2.33; 95% CI, 1.20-4.51) vs older ones (aHR, 1.36; 95% CI, 0.77-2.39).

Conclusions and Relevance

High-risk plaque found by coronary CTA was associated with a future MACE in a large US population of outpatients with stable chest pain. High-risk plaque may be an additional risk stratification tool, especially in patients with nonobstructive coronary artery disease, younger patients, and women. The importance of findings is limited by low absolute MACE rates and low positive predictive value of high-risk plaque.

Trial Registration

clinicaltrials.gov Indentifier: NCT01174550.

Influence of irregular heart rhythm on radiation exposure, image quality and diagnostic impact of cardiac computed tomography angiography in 4,339 patients. Data from the German Cardiac Computed Tomography Registry

BACKGROUND

Coronary computed tomography angiography (coronary CTA) provides non-invasive evaluation of the coronary arteries with high precision for the detection of significant coronary artery disease (CAD).

AIM

To investigate whether irregular heart rhythm including atrial fibrillation and premature beats during data acquisition influences (i) radiation and contrast media exposure, (ii) number of non-evaluable coronary segments and (iii) diagnostic impact of coronary CTA.

METHODS

Twelve tertiary care centers with ≥64 slice CT scanners and ≥5 years of experience with cardiovascular imaging participated in this registry. Between 2009 and 2014, 4339 examinations were analysed in patients who underwent clinically indicated coronary CTA for suspected CAD. Clinical and epidemiologic data were gathered from all patients. In addition, clinical presentation, heart rate and rhythm during the scan, Agatston score, radiation and contrast media exposure and the diagnostic impact of coronary CTA were systematically analysed.

RESULTS

Of 4339 patients in total, 260 (6.0%) had irregular heart rhythm, whereas the remaining 4079 (94.0%) had stable sinus rhythm. Patients with irregular heart rhythm were older (63.2 ± 12.5yrs versus 58.6 ± 11.4yrs. p < 0.001), exhibited a higher rate of pathologic stress tests before CTA (37.1% versus 26.1%, p < 0.01) and higher heart rates during CTA compared to those with sinus rhythm (62.5 ± 11.6bpm versus 58.9 ± 8.5bpm, p < 0.001). Both contrast media exposure and radiation exposure were significantly higher in patients with irregular heart rhythm (90 mL (95%CI = 80-110 mL) versus 80 mL (95%CI = 70-90 mL) and 6.2 mSv (95%CI = 2.5-11.7) versus 3.3 mSv (95%CI = 1.7-6.9), p < 0.001 for both). Coronary CTA excluded significant CAD less frequently in patients with irregular heart rhythm (32.9% versus 44.8%, p < 0.001). This was attributed to the higher rate of examinations with at least one non-diagnostic coronary segment in patients with irregular heart rhythm (10.8% versus 4.6%, p < 0.001). Subsequent invasive angiography could be avoided in 47.2% of patients with irregular heart rhythm compared to 52.9% of patients with sinus rhythm (p = NS), whereas downstream stress testing was recommended in 3.2% of patients with irregular heart rhythm versus 4.0% of patients with sinus rhythm (p = NS).

CONCLUSION

A significant number of patients scheduled for coronary CTA have irregular heart rhythm in a real-world clinical setting. In such patients, heart rate during coronary CTA is higher, possibly resulting in (i) higher radiation and contrast agent exposure and (ii) more frequent coronary CTA examinations with at least one non-diagnostic coronary artery segment. However, this does not seem to lead to increased downstream stress testing or subsequent invasive procedures.

Effect of Percutaneous Coronary Intervention on Survival in Patients with Stable Ischemic Heart Disease

PURPOSE OF REVIEW

This study aims to determine if percutaneous coronary intervention (PCI) does improve survival in stable ischemic heart disease (SIHD).

RECENT FINDINGS

The International Study of Comparative Health Effectiveness with Medical and Invasive Approaches (ISCHEMIA) trial will evaluate patients with moderate to severe ischemia and will be the largest randomized trial of an initial management strategy of coronary revascularization (percutaneous or surgical) versus optimal medical therapy alone for SIHD. Although the ISCHEMIA trial may show a benefit with upfront coronary revascularization in this high-risk population, cardiac events after PCI are largely caused by plaque rupture in segments outside of the original stented segment. Furthermore, given the robust data from prior randomized trials, which showed no survival benefit with PCI, and the likelihood that the highest risk patients in ISCHEMIA will be treated with surgery, it is unlikely that the ISCHEMIA trial will show a survival benefit particular to PCI.

RECENT FINDINGS

Although PCI relieves symptoms, the evidence base indicates that it does not prolong survival in SIHD.

Flow Mediated Dilatation as a Biomarker in Vascular Surgery Research

Endothelial dysfunction is one of the hallmarks of atherogenesis, and correlates with many cardiovascular risk factors. One of the features of endothelial dysfunction is the loss of nitric oxide (NO) bioavailability, resulting in derangements in the vasodilatory response of the vessel wall. Flow mediated dilatation (FMD) of the brachial artery is an accepted method for non-invasive assessment of systemic endothelial function. FMD is examined extensively in the context of cardiovascular research, and has been utilised as a routine assessment in large cohorts such as the Framingham Heart Study, Young Finns Study, and Gutenberg Heart Study. However, FMD is less known in the context of vascular surgery research, despite the similarities between the underpinning disease mechanisms. This review will provide a summary of FMD in terms of its history of development and the conduct of the test in research settings. It will further highlight the key literature of FMD as a biomarker for vascular surgeons, particularly in the context of abdominal aortic aneurysms and lower limb peripheral arterial disease.

Prognostic Value of Noninvasive Cardiovascular Testing in Patients With Stable Chest Pain: Insights From the PROMISE Trial (Prospective Multicenter Imaging Study for Evaluation of Chest Pain)

BACKGROUND

Optimal management of patients with stable chest pain relies on the prognostic information provided by noninvasive cardiovascular testing, but there are limited data from randomized trials comparing anatomic with functional testing.

METHODS

In the PROMISE trial (Prospective Multicenter Imaging Study for Evaluation of Chest Pain), patients with stable chest pain and intermediate pretest probability for obstructive coronary artery disease (CAD) were randomly assigned to functional testing (exercise electrocardiography, nuclear stress, or stress echocardiography) or coronary computed tomography angiography (CTA). Site-based diagnostic test reports were classified as normal or mildly, moderately, or severely abnormal. The primary end point was death, myocardial infarction, or unstable angina hospitalizations over a median follow-up of 26.1 months.

RESULTS

Both the prevalence of normal test results and incidence rate of events in these patients were significantly lower among 4500 patients randomly assigned to CTA in comparison with 4602 patients randomly assigned to functional testing (33.4% versus 78.0%, and 0.9% versus 2.1%, respectively; both P<0.001). In CTA, 54.0% of events (n=74/137) occurred in patients with nonobstructive CAD (1%-69% stenosis). Prevalence of obstructive CAD and myocardial ischemia was low (11.9% versus 12.7%, respectively), with both findings having similar prognostic value (hazard ratio, 3.74; 95% confidence interval [CI], 2.60-5.39; and 3.47; 95% CI, 2.42-4.99). When test findings were stratified as mildly, moderately, or severely abnormal, hazard ratios for events in comparison with normal tests increased proportionally for CTA (2.94, 7.67, 10.13; all P<0.001) but not for corresponding functional testing categories (0.94 [P=0.87], 2.65 [P=0.001], 3.88 [P<0.001]). The discriminatory ability of CTA in predicting events was significantly better than functional testing (c-index, 0.72; 95% CI, 0.68-0.76 versus 0.64; 95% CI, 0.59-0.69; P=0.04). If 2714 patients with at least an intermediate Framingham Risk Score (>10%) who had a normal functional test were reclassified as being mildly abnormal, the discriminatory capacity improved to 0.69 (95% CI, 0.64-0.74).

CONCLUSIONS

Coronary CTA, by identifying patients at risk because of nonobstructive CAD, provides better prognostic information than functional testing in contemporary patients who have stable chest pain with a low burden of obstructive CAD, myocardial ischemia, and events.

CLINICAL TRIAL REGISTRATION

URL: http://www.clinicaltrials.gov. Unique identifier: NCT01174550.

Flow Mediated Dilatation and Progression of Abdominal Aortic Aneurysms

OBJECTIVE/BACKGROUND

Biomarker(s) for prediction of the future progression rate of abdominal aortic aneurysms (AAA) may be useful to stratify the management of individual patients. AAAs are associated with features of systemic inflammation and endothelial dysfunction. Flow mediated dilatation (FMD) of the brachial artery is a recognised non-invasive measurement for endothelial function. We hypothesised that FMD is a potential biomarker of AAA progression and reflects the temporal changes of endothelial function during AAA progression.

METHODS

In a prospectively recruited cohort of patients with AAAs (Oxford Abdominal Aortic Aneurysm Study), AAA size was recorded by antero-posterior diameter (APD) (outer to outer) on ultrasound. Annual AAA progression was calculated by (ΔAPD/APD at baseline)/(number of days lapsed/365 days). FMD was assessed at the same time as AAA size measurement. Analyses of data were performed in the overall cohort, and further in subgroups of AAA by size (small: 30-39 mm; moderate: 40-55 mm; large: > 55 mm).

RESULTS

FMD is inversely correlated with the diameter of AAAs in all patients (n=162, Spearman's r=-.28, p<.001). FMD is inversely correlated with AAA diameter progression in the future 12 months (Spearman's r=-.35, p=.001), particularly in the moderate size group. Furthermore, FMD deteriorates during the course of AAA surveillance (from a median of 2.0% at baseline to 1.2% at follow-up; p=.004), while surgical repair of AAAs (n=50 [open repair n=22, endovascular repair n=28)] leads to an improvement in FMD (from 1.1% pre-operatively to 3.8% post-operatively; p<.001), irrespective of the type of surgery.

CONCLUSION

FMD is inversely correlated with future AAA progression in humans. FMD deteriorates during the natural history of AAA, and is improved by surgery. The utility of FMD as a potential biomarker in the context of AAA warrants further investigation.

Factors Associated With Coronary Artery Disease Progression Assessed By Serial Coronary Computed Tomography Angiography

Background

Coronary computed tomography angiography (CCTA) allows for noninvasive coronary artery disease (CAD) phenotyping. Factors related to CAD progression are epidemiologically valuable.

Objective

To identify factors associated with CAD progression in patients undergoing sequential CCTA testing.

Methods

We retrospectively analyzed 384 consecutive patients who had at least two CCTA studies between December 2005 and March 2013. Due to limitations in the quantification of CAD progression, we excluded patients who had undergone surgical revascularization previously or percutaneous coronary intervention (PCI) between studies. CAD progression was defined as any increase in the adapted segment stenosis score (calculated using the number of diseased segments and stenosis severity) in all coronary segments without stent (in-stent restenosis was excluded from the analysis). Stepwise logistic regression was used to assess variables associated with CAD progression.

Results

From a final population of 234 patients, a total of 117 (50%) had CAD progression. In a model accounting for major CAD risk factors and other baseline characteristics, only age (odds ratio [OR] 1.04, 95% confidence interval [95%CI] 1.01-1.07), interstudy interval (OR 1.03, 95%CI 1.01-1.04), and past PCI (OR 3.66, 95%CI 1.77-7.55) showed an independent relationship with CAD progression.

Conclusions

A history of PCI with stent placement was independently associated with a 3.7-fold increase in the odds of CAD progression, excluding in-stent restenosis. Age and interstudy interval were also independent predictors of progression.

Near-Infrared Spectroscopy Enhances Intravascular Ultrasound Assessment of Vulnerable Coronary Plaque: A Combined Pathological and In Vivo Study

OBJECTIVES

Pathological studies demonstrate the dual significance of plaque burden (PB) and lipid composition for mediating coronary plaque vulnerability. We evaluated relationships between intravascular ultrasound (IVUS)-derived PB and arterial remodeling with near-infrared spectroscopy (NIRS)-derived lipid content in ex vivo and in vivo human coronary arteries.

APPROACH AND RESULTS

Ex vivo coronary NIRS and IVUS imaging was performed through blood in 116 coronary arteries of 51 autopsied hearts, followed by 2-mm block sectioning (n=2070) and histological grading according to modified American Heart Association criteria. Lesions were defined as the most heavily diseased 2-mm block per imaged artery on IVUS. IVUS-derived PB and NIRS-derived lipid core burden index (LCBI) of each block and lesion were analyzed. Block-level analysis demonstrated significant trends of increasing PB and LCBI across more complex atheroma (Ptrend <0.001 for both LCBI and PB). Lesion-based analyses demonstrated the highest LCBI and remodeling index within coronary fibroatheroma (Ptrend <0.001 and 0.02 versus all plaque groups, respectively). Prediction models demonstrated similar abilities of PB, LCBI, and remodeling index for discriminating fibroatheroma (c indices: 0.675, 0.712, and 0.672, respectively). A combined PB+LCBI analysis significantly improved fibroatheroma detection accuracy (c index 0.77, P=0.028 versus PB; net-reclassification index 43%, P=0.003), whereas further adding remodeling index did not (c index 0.80, P=0.27 versus PB+LCBI). In vivo comparisons of 43 age- and sex-matched patients (to the autopsy cohort) undergoing combined NIRS-IVUS coronary imaging yielded similar associations to those demonstrated ex vivo.

CONCLUSIONS

Adding NIRS to conventional IVUS-derived PB imaging significantly improves the ability to detect more active, potentially vulnerable coronary atheroma.

High-grade culprit lesions are a common cause of ST-segment elevation myocardial infarction

INTRODUCTION

Conventional knowledge holds that the majority of ruptured atherosclerotic plaques causing ST-segment elevation myocardial infarction (STEMI) are found in moderate stenoses that produce < 50% loss of arterial diameter. This study aimed to analyse the culprit lesions in patients who presented with STEMI and underwent primary percutaneous coronary intervention (PPCI) at our institution.

METHODS

Patients who underwent PPCI between June 2008 and August 2010 at our institution were included in the analysis. Quantitative coronary angiography was performed for the culprit lesions immediately after antegrade flow was restored by thrombectomy, low-profile balloon predilatation or guidewire crossing.

RESULTS

A total of 1,021 patients were included in the study. The mean age was 57 ± 12 years and 85.2% were male. Lesion measurement was done after coronary flow was restored by thrombectomy (73.1%), balloon dilatation (24.1%) and following guidewire passage across the lesion (2.8%). Mean minimal luminal diameter was 1.1 ± 0.5 mm, mean reference vessel diameter was 2.8 ± 0.6 mm, mean diameter stenosis was 61 ± 16% and mean lesion length was 16 ± 6 mm. Most (80.2%) of the culprit lesions had diameter stenoses > 50% (p < 0.01). Although balloon angioplasty was performed in 24.1% of the patients, the majority (64.2%) still had diameter stenoses > 50%. High-grade stenoses (> 50%) were more frequently observed in male patients (p = 0.04).

CONCLUSION

Contrary to the existing paradigm, we found that most of the patients with STEMI in our institution had culprit lesions with diameter stenosis > 50%.

Predicting outcome in the COURAGE trial (Clinical Outcomes Utilizing Revascularization and Aggressive Drug Evaluation): coronary anatomy versus ischemia

OBJECTIVES

The aim of this study was to determine the relative utility of anatomic and ischemic burden of coronary artery disease for predicting outcomes.

BACKGROUND

Both anatomic burden and ischemic burden of coronary artery disease determine patient prognosis and influence myocardial revascularization decisions. When both measures are available, their relative utility for prognostication and management choice is controversial.

METHODS

A total of 621 patients enrolled in the COURAGE (Clinical Outcomes Utilizing Revascularization and Aggressive Drug Evaluation) trial with baseline quantitative nuclear single-photon emission computed tomography (SPECT) and quantitative coronary angiography were studied. Several multiple regression models were constructed to determine independent predictors of the endpoint of death, myocardial infarction (MI) (excluding periprocedural MI) and non-ST-segment elevation acute coronary syndromes (NSTE-ACS). Ischemic burden during stress SPECT, anatomic burden derived from angiography, left ventricular ejection fraction, and assignment to either optimal medical therapy (OMT) + percutaneous coronary intervention (PCI) or OMT alone were analyzed.

RESULTS

In nonadjusted and adjusted regression models, anatomic burden and left ventricular ejection fraction were consistent predictors of death, MI, and NSTE-ACS, whereas ischemic burden and treatment assignment were not. There was a marginal (p = 0.03) effect of the interaction term of anatomic and ischemic burden for the prediction of clinical outcome, but separately or in combination, neither anatomy nor ischemia interacted with therapeutic strategy to predict outcome.

CONCLUSIONS

In a cohort of patients treated with OMT, anatomic burden was a consistent predictor of death, MI, and NSTE-ACS, whereas ischemic burden was not. Importantly, neither determination, even in combination, identified a patient profile benefiting preferentially from an invasive therapeutic strategy. (Clinical Outcomes Utilizing Revascularization and Aggressive Drug Evaluation [COURAGE]; NCT00007657).

Prognostic importance of coronary anatomy and left ventricular ejection fraction despite optimal therapy: assessment of residual risk in the Clinical Outcomes Utilizing Revascularization and Aggressive DruG Evaluation Trial

BACKGROUND

It is unknown if baseline angiographic findings can be used to estimate residual risk of patients with chronic stable angina treated with both optimal medical therapy (OMT) and protocol-assigned or symptom-driven percutaneous coronary intervention (PCI).

METHODS

Death, myocardial infarction (MI), and hospitalization for non-ST-segment elevation acute coronary syndrome were adjudicated in 2,275 COURAGE patients. The number of vessels diseased (VD) was defined as the number of major coronary arteries with ≥50% diameter stenosis. Proximal left anterior descending, either isolated or in combination with other disease, was also evaluated. Depressed left ventricular ejection fraction (LVEF) was defined as ≤50%. Cox regression analyses included these anatomical factors as well as interaction terms for initial treatment assignment (OMT or OMT + PCI).

RESULTS

Percutaneous coronary intervention and proximal left anterior descending did not influence any outcome. Death was predicted by low LVEF (hazard ratio [HR] 1.86, CI 1.34-2.59, P < .001) and VD (HR 1.45, CI 1.20-1.75, P < .001). Myocardial infarction and non-ST-segment elevation acute coronary syndrome were predicted only by VD (HR 1.53, CI 1.30-1.81 and HR 1.24, CI 1.06-1.44, P = .007, respectively).

CONCLUSIONS

In spite of OMT and irrespective of protocol-assigned or clinically driven PCI, LVEF and angiographic burden of disease at baseline retain prognostic power and reflect residual risk for secondary ischemic events.

Multislice computed tomographic coronary angiography for quantitative assessment of culprit lesions in acute coronary syndromes

BACKGROUND

We studied the characteristics of low-density plaque (LDP) burden in patients with acute coronary syndrome (ACS), using 64-slice computed tomography (CT) assessment. Though several CT plaque features such as positive remodelling, adjacent spotty calcification or the presence of LDP have been demonstrated to be associated with unstable plaques, it is still unknown whether their severity and extent present any differences between different types of ACS.

METHODS

In 45 subjects with ACS (22 unstable angina and 23 non-ST-elevation myocardial infarction [NSTEMI]), 118 coronary plaques were evaluated using a CT multislice 64 assessment including the burden with atheroma having a CT density below 30, 60, or 100 Hounsfield units (HU), remodelling index and spotty calcification.

RESULTS

Culprit lesions tend to be larger in volume (111.11 mm(3) vs 62.25 mm(3); P < 0.0001), have a higher remodelling index (1.27 vs 1.01; P < 0.0001), and present a significantly larger LDP with a density < 30 HU (23.3 mm(3) vs 7.6 mm(3); P < 0.0001) or < 60 HU (33.4 mm(3) vs 16.9 mm(3); P < 0.0001) than nonculprit lesions. The presence of a plaque more than 20 mm(3) in volume with a CT density < 30 HU (P = 0.0009) and the presence of all 3 markers of plaque vulnerability (LDP, spotty calcifications or positive remodelling) (P = 0.01) significantly correlated with the presence of an NSTEMI.

CONCLUSIONS

Culprit lesions demonstrated larger plaque volumes, a higher burden with low-density cores, and more intense remodelling than nonculprit lesions, whereas culprit lesions associated with NSTEMI showed a higher burden with lower density cores than those associated with unstable angina.

Risk factor reduction in progression of angiographic coronary artery disease

INTRODUCTION

To investigate differences between outpatients with progressive and nonprogressive coronary artery disease (CAD) measured by coronary angiography.

MATERIAL AND METHODS

Chart reviews were performed in patients in an outpatient cardiology practice having ≥ 2 coronary angiographies ≥ 1 year apart. Progressive CAD was defined as 1) new non-obstructive or obstructive CAD in a previously disease-free vessel; or 2) new obstruction in a previously non-obstructive vessel. Coronary risk factors, comorbidities, cardiovascular events, medication use, serum low-density lipoprotein cholesterol (LDL-C), and blood pressure were used for analysis.

RESULTS

The study included 183 patients, mean age 71 years. Mean follow-up duration was 11 years. Mean follow-up between coronary angiographies was 58 months. Of 183 patients, 108 (59%) had progressive CAD, and 75 (41%) had nonprogressive CAD. The use of statins, β-blockers, angiotensin-converting enzyme inhibitors or angiotensin receptor blockers, and aspirin was not significantly different in patient with progressive CAD or nonprogressive CAD Mean arterial pressure was higher in patients with progressive CAD than in patients with nonprogressive CAD (97±13 mm Hg vs. 92±12 mm Hg) (p<0.05). Serum LDL-C was insignificantly higher in patients with progressive CAD (94±40 mg/dl) than in patients with nonprogressive CAD (81±34 mg/dl) (p=0.09).

CONCLUSIONS

Our data suggest that in addition to using appropriate medical therapy, control of blood pressure and serum LDL-C level may reduce progression of CAD.