Prognostic Value of Coronary CT Angiography in Patients With Non-ST-Segment Elevation Acute Coronary Syndromes

BACKGROUND

Severity and extent of coronary artery disease (CAD) assessed by invasive coronary angiography (ICA) guide treatment and may predict clinical outcome in patients with non-ST-segment elevation acute coronary syndrome (NSTEACS).

OBJECTIVES

This study tested the hypothesis that coronary computed tomography angiography (CTA) is equivalent to ICA for risk assessment in patients with NSTEACS.

METHODS

The VERDICT (Very Early Versus Deferred Invasive Evaluation Using Computerized Tomography in Patients With Acute Coronary Syndromes) trial evaluated timing of treatment in relation to outcome in patients with NSTEACS and included a clinically blinded coronary CTA conducted prior to ICA. Severity of CAD was defined as obstructive (coronary stenosis ≥50%) or nonobstructive. Extent of CAD was defined as high risk (obstructive left main or proximal left anterior descending artery stenosis and/or multivessel disease) or non-high risk. The primary endpoint was a composite of all-cause death, nonfatal recurrent myocardial infarction, hospital admission for refractory myocardial ischemia, or heart failure.

RESULTS

Coronary CTA and ICA were conducted in 978 patients. During a median follow-up time of 4.2 years (interquartile range: 2.7 to 5.5 years), the primary endpoint occurred in 208 patients (21.3%). The rate of the primary endpoint was up to 1.7-fold higher in patients with obstructive CAD compared with in patients with nonobstructive CAD as defined by coronary CTA (hazard ratio [HR]: 1.74; 95% confidence interval [CI]: 1.22 to 2.49; p = 0.002) or ICA (HR: 1.54; 95% CI: 1.13 to 2.11; p = 0.007). In patients with high-risk CAD, the rate of the primary endpoint was 1.5-fold higher compared with the rate in those with non-high-risk CAD as defined by coronary CTA (HR: 1.56; 95% CI: 1.18 to 2.07; p = 0.002). A similar trend was noted for ICA (HR: 1.28; 95% CI: 0.98 to 1.69; p = 0.07).

CONCLUSIONS

Coronary CTA is equivalent to ICA for the assessment of long-term risk in patients with NSTEACS. (Very Early Versus Deferred Invasive Evaluation Using Computerized Tomography in Patients With Acute Coronary Syndromes [VERDICT]; NCT02061891).

Coronary CT Angiography in Patients With Non-ST-Segment Elevation Acute Coronary Syndrome

BACKGROUND

In patients with non-ST-segment elevation acute coronary syndrome (NSTEACS), coronary pathology may range from structurally normal vessels to severe coronary artery disease.

OBJECTIVES

The purpose of this study was to test if coronary computed tomography angiography (CTA) may be used to exclude coronary artery stenosis ≥50% in patients with NSTEACS.

METHODS

The VERDICT (Very Early Versus Deferred Invasive Evaluation Using Computerized Tomography in Patients With Acute Coronary Syndromes) trial (NCT02061891) evaluated the outcome of patients with confirmed NSTEACS randomized 1:1 to very early (within 12 h) or standard (48 to 72 h) invasive coronary angiography (ICA). As an observational component of the trial, a clinically blinded coronary CTA was conducted prior to ICA in both groups. The primary endpoint was the ability of coronary CTA to rule out coronary artery stenosis (≥50% stenosis) in the entire population, expressed as the negative predictive value (NPV), using ICA as the reference standard.

RESULTS

Coronary CTA was conducted in 1,023 patients-very early, 2.5 h (interquartile range [IQR]: 1.8 to 4.2 h), n = 583; and standard, 59.9 h (IQR: 38.9 to 86.7 h); n = 440 after the diagnosis of NSTEACS was made. A coronary stenosis ≥50% was found by coronary CTA in 68.9% and by ICA in 67.4% of the patients. Per-patient NPV of coronary CTA was 90.9% (95% confidence interval [CI]: 86.8% to 94.1%) and the positive predictive value, sensitivity, and specificity were 87.9% (95% CI: 85.3% to 90.1%), 96.5% (95% CI: 94.9% to 97.8%) and 72.4% (95% CI: 67.2% to 77.1%), respectively. NPV was not influenced by patient characteristics or clinical risk profile and was similar in the very early and the standard strategy group.

CONCLUSIONS

Coronary CTA has a high diagnostic accuracy to rule out clinically significant coronary artery disease in patients with NSTEACS.

Relationship Between Two Common Lipoprotein Lipase Variants and the Metabolic Syndrome and Its Individual Components

BACKGROUND

Common lipoprotein lipase (LPL) variants are important determinants of triglycerides (TG) and high-density lipoprotein (HDL) cholesterol (C) concentrations. High TG/low HDL-C tend to cluster with hypertension, glucose intolerance, and abdominal obesity and comprise the metabolic syndrome (MetS). The role of LPL variants as a cause of MetS is unclear. This study investigated the relationship between two common LPL variants and the presence of MetS and its individual components.

METHODS

Cross-sectional study, including 2348 Danish women (50.7%) and men, age 41-72 years, without known cardiovascular disease. Carrier status for the two common LPL variants: 447Ter (low TG/high HDL-C) and 291Ser (high TG/low HDL-C) was determined. The prevalence of MetS according to the National Cholesterol Education Program criteria was 16.6%.

RESULTS

Of the 2348 participants, 19.8% had the 447Ter variant and 4.9% had the 291Ser variant. Compared with the reference variant, the prevalence of MetS was lower in carriers of the 447Ter variant (11.2% vs. 17.9%, P < 0.001) but with no difference in carriers of the 291Ser variant (18.4% vs. 16.5%, P = 0.59). Adjusted for age, sex, smoking, physical activity, alcohol consumption, and highest sex-specific insulin quartile, the relative risk of MetS was 0.63 (95% confidence interval [CI] 0.45-0.89, P < 0.01) for carriers of the 447Ter variant and 1.20 (95% CI 0.70-2.03, P > 0.05) for carriers of the 291Ser variant. Both LPL variants were associated with high TG/low HDL-C (P < 0.01), but not with the MetS components waist circumference, hypertension, and glucose intolerance (P > 0.05).

CONCLUSION

The two common LPL variants were associated with MetS through their effect on high TG/low HDL-C.

Symptomatic venous thromboembolism following fractures distal to the knee: a nationwide Danish cohort study

BACKGROUND

Our aims were to determine the incidence of symptomatic deep venous thrombosis (DVT) and pulmonary embolism (PE) that required inpatient or outpatient treatment, and to identify specific risk factors associated with DVT/PE in patients who had undergone surgery for a fracture distal to the knee.

METHODS

Using individual linkage of nationwide registries, we included all Danish patients who had undergone surgery for a fracture distal to the knee between 1999 and 2011. Patients were followed for 180 days from discharge. Event rates of DVT/PE were calculated, and significant risk factors were identified with use of multivariable Cox regression analyses. Routine postdischarge antithrombotic chemoprophylaxis was not given to these patients.

RESULTS

The study included 57,619 patients, 594 of whom had a venous thromboembolic event during the follow-up period. Thirty-nine (6.6%) of the 594 events were death due to PE. The overall event rate during the 180-day study period was 1.0%. The incidence rate was 7.28 events per 100 person-years before discharge, decreasing to a stable level below one event per 100 person-years in week 13 to 14 after discharge. Use of oral contraception by patients eighteen to fifty years of age (hazard ratio [HR] = 5.23, 95% confidence level [CI] = 3.35 to 8.18), previous DVT (HR = 6.27, 95% CI = 4.18 to 9.40), previous PE (HR = 5.45, 95% CI = 3.05 to 9.74), coagulopathy (HR = 2.47, 95% CI = 1.07 to 5.72), and peripheral artery disease (HR = 2.34, 95% CI = 1.20 to 4.56) were the factors associated with the highest risk of postoperative DVT/PE. Also, increasing age, increasing body mass index, cancer, and treatment with nonsteroidal anti-inflammatory drugs were associated with a significantly increased risk of DVT/PE.

CONCLUSIONS

The incidence of DVT/PE was low following surgery for fractures distal to the knee; however, the risk was increased in the presence of a number of risk factors. This study suggests that specific groups of patients undergoing surgery for a fracture distal to the knee might benefit from postdischarge antithrombotic treatment.

Soluble Urokinase Plasminogen Activator Receptor for Risk Prediction in Patients Admitted with Acute Chest Pain

BACKGROUND

Plasma concentrations of soluble urokinase plasminogen activator receptor (suPAR) predict mortality in several clinical settings, but the long-term prognostic importance of suPAR in chest pain patients admitted on suspicion of non–ST-segment elevation acute coronary syndrome (NSTEACS) is uncertain.

METHODS

suPAR concentrations were measured on admission in 449 consecutive chest pain patients in a single center between January 3, 2005, and February 14, 2006. Patients were followed for all-cause mortality from discharge until July 28, 2011.

RESULTS

The diagnoses at discharge comprised high-risk NSTEACS [non–ST elevation myocardial infarction or unstable angina with electrocardiogram (ECG) abnormalities] in 77 patients (17.2%) and low-risk NSTEACS without evidence of myocardial ischemia in 257 (57.2%) of patients. Another 115 (25.6%) of patients received other diagnoses. During a median follow-up of 5.7 years (range, 0.01–6.6 years) there were 162 (36.1%) deaths. suPAR was predictive of mortality independent of age, sex, smoking, final diagnosis for the hospitalization, comorbidities (diabetes, hypertension, previous myocardial infarction, and heart failure), and variables measured on the day of admission (renal function, inflammatory markers, and markers of myocardial ischemia) with a hazard ratio (95% CI) of 1.93 (1.48–2.51) per SD increase in log-transformed suPAR, P &lt; 0.0001. The use of suPAR improved the predictive accuracy of abnormal ECG findings and increased troponin concentrations regarding all-cause mortality (c statistics, 0.751–0.805; P &lt; 0.0001).

CONCLUSIONS

suPAR is a strong predictor of adverse long-term outcomes and improves risk stratification beyond traditional risk variables in chest pain patients admitted with suspected NSTEACS.

Risk stratification in stable coronary artery disease is possible at cardiac troponin levels below conventional detection and is improved by use of N-terminal pro-B-type natriuretic peptide

AIMS

Low prevalence of detectable cardiac troponin in healthy people and low-risk patients previously curtailed its use. With a new high-sensitive cardiac troponin assay (hs-cTnT), concentrations below conventional detection may have prognostic value, notably in combination with N-terminal pro-B-type natriuretic peptide (NT-pro-BNP).

METHODS AND RESULTS

Biomarker concentrations were determined from serum obtained at enrolment in the CLARICOR trial involving 4197 patients with stable coronary artery disease (CAD) followed for 2.6 years. Serum hs-cTnT was detectable (above 3 ng/l) in 78% and above the conventional 99th percentile (13.5 ng/l) in 23%. Across all levels of hs-cTnT there was a graded increase in the risk of cardiovascular death after adjustment for known prognostic indicators: hazard ratio (HR) per unit increase in the natural logarithm of the hs-cTnT level, 1.49; 95% confidence interval (CI), 1.23-1.81; similarly for all-cause mortality (HR 1.48, 95% CI 1.29-1.70) and myocardial infarction (HR 1.37, 95% CI 1.13-1.67). Increasing values of hs-cTnT were associated with increased mortality across all values of NT-pro-BNP, but this was particularly prominent when NT-pro-BNP >400 ng/l.

CONCLUSIONS

In patients with stable CAD, any detectable hs-cTnT level is significantly associated with all-cause mortality, cardiovascular death, and myocardial infarction after adjustment for traditional risk factors and NT-pro-BNP. Excess mortality is particularly pronounced in patients with NT-pro-BNP >400 ng/l.

Association of clopidogrel treatment with risk of mortality and cardiovascular events following myocardial infarction in patients with and without diabetes

CONTEXT

Pharmacodynamic studies have shown that persistently high platelet reactivity is common in patients with diabetes in spite of clopidogrel treatment. Clinical trials have not convincingly demonstrated that clopidogrel benefits patients with diabetes as much patients without diabetes.

OBJECTIVES

To estimate the clinical effectiveness associated with clopidogrel treatment after myocardial infarction (MI) in patients with diabetes.

DESIGN, SETTING, AND PATIENTS

By individual-level linkage of the Danish nationwide administrative registries between 2002-2009, patients who were hospitalized with incident MI and who had survived and not undergone coronary artery bypass surgery 30 days after discharge were followed up for as long as 1 year (maximally until December 31, 2009). Adjusted for age, sex, comorbidity, calendar year, concomitant pharmacotherapy, and invasive interventions, hazard ratios that were associated with clopidogrel in patients with and without diabetes were analyzed by Cox proportional-hazard models and propensity score-matched models.

MAIN OUTCOME MEASURES

All-cause mortality, cardiovascular mortality, and a composite end point of recurrent MI and all-cause mortality.

RESULTS

Of the 58,851 patients included in the study, 7247 (12%) had diabetes and 35,380 (60%) received clopidogrel. In total, 1790 patients (25%) with diabetes and 7931 patients (15%) without diabetes met the composite end point. Of these, 1225 (17%) with and 5377 (10%) without diabetes died. In total, 978 patients (80%) with and 4100 patients (76%) without diabetes died of events of cardiovascular origin. For patients with diabetes who were treated with clopidogrel, the unadjusted mortality rates (events/100 person-years) were 13.4 (95% CI, 12.8-14.0) vs 29.3 (95% CI, 28.3-30.4) for those not treated. For patients without diabetes who were treated with clopidogrel, the unadjusted mortality rates were 6.4 (95% CI, 6.3-6.6) vs 21.3 (95% CI, 21.0-21.7) for those not treated. However, among patients with diabetes vs those without diabetes, clopidogrel was associated with less effectiveness for all-cause mortality (HR, 0.89 [95% CI, 0.79-1.00] vs 0.75 [95% CI, 0.70-0.80]; P for interaction, .001) and for cardiovascular mortality (HR, 0.93 [95% CI, 0.81-1.06] vs 0.77 [95% CI, 0.72-0.83]; P for interaction, .01) but not for the composite end point (HR, 1.00 [95% CI, 0.91-1.10] vs 0.91 [95% CI, 0.87-0.96]; P for interaction, .08). Propensity score-matched models gave similar results.

CONCLUSION

Among patients with diabetes compared with patients without diabetes, the use of conventional clopidogrel treatment after MI was associated with lower reduction in the risk of all-cause death and cardiovascular death.

Cell-specific detection of microRNA expression during cardiomyogenesis by combined in situ hybridization and immunohistochemistry

MicroRNAs (miRNAs) regulate gene expression by mediating translational repression or mRNA degradation of their targets, and several miRNAs control developmental decisions through embryogenesis. In the developing heart, miRNA targets comprise key players mediating cardiac lineage determination. However, although several miRNAs have been identified as differentially regulated during cardiac development and disease, their distinct cell-specific localization remains largely undetermined, likely owing to a lack of adequate methods. We therefore report the development of a markedly improved approach combining fluorescence-based miRNA-in situ hybridization (miRNA-ISH) with immunohistochemistry (IHC). We have applied this protocol to differentiating embryoid bodies (EBs) as well as embryonic and adult mouse hearts, to detect miRNAs that were upregulated during EB cardiomyogenesis, as determined by array-based miRNA expression profiling. In this manner, we found specific co-localization of miR-1 to myosin positive cells (cardiomyocytes) of EBs, developing and mature hearts. In contrast, miR-125b and -199a did not localize to cardiomyocytes, as previously suggested for miR-199a, but were rather expressed in connective tissue cells of the heart. More specifically, by co-staining with α-smooth muscle actin (α-SMA) and collagen-I, we found that miR-125b and -199a localize to perivascular α-SMA(-) stromal cells. Our approach thus proved valid for determining cell-specific localization of miRNAs, and the findings we present highlight the importance of determining exact cell-specific localization of miRNAs by sequential miRNA-ISH and IHC in studies aiming at understanding the role of miRNAs and their targets. This approach will hopefully aid in identifying relevant miRNA targets of both the heart and other organs.

Soluble urokinase plasminogen activator receptor is associated with subclinical organ damage and cardiovascular events

OBJECTIVE

The soluble urokinase plasminogen activator receptor (suPAR) is a plasma marker of low grade inflammation and has been associated with cardiovascular risk. We wanted to investigate whether suPAR was associated with markers of subclinical organ damage.

METHODS

In a population sample of 2038 individuals, aged 41, 51, 61 and 71 years, without diabetes, prior stroke or myocardial infarction, not receiving any cardiovascular, anti-diabetic or lipid-lowering medications, we measured urine albumin/creatinine ratio (UACR), carotid atherosclerotic plaques and carotid/femoral pulse wave-velocity (PWV) together with traditional cardiovascular risk factors and high sensitivity C-reactive protein (hsCRP).

RESULTS

suPAR was significantly associated with the presence of plaques (P = 0.003) and UACR (P < 0.001), but not PWV (P = 0.17) when adjusting for age, gender, systolic blood pressure, cholesterol, plasma glucose, waist/hip ratio, smoking and hsCRP. However, suPAR explained only a small part of the variation in the markers of subclinical organ damage (R(2) 0.02-0.04). During a median follow-up of 12.7 years (5th-95th percentile 5.1-13.4 years) a total of 174 composite endpoints (CEP) of cardiovascular death, non-fatal myocardial infarction and stroke occurred. suPAR was associated with CEP independent of plaques, PWV, UACR, and hsCRP as well as age, gender, systolic blood pressure, cholesterol, plasma glucose, waist/hip ratio and smoking with a standardized hazard ratio of 1.16 (95% confidence interval 1.04-1.28, P = 0.006).

CONCLUSION

suPAR was associated with subclinical organ damage, but predicted cardiovascular events independent of subclinical organ damage, traditional risk factors and hsCRP. Further studies must investigate whether suPAR plays an independent role in the pathogenesis of cardiovascular disease.