Independent Predictor Of Ischemia Research Articles

The role of myocardial perfusion imaging in predicting myocardial ischemia in patients diagnosed with long COVID.

Incomplete recovery with long-term complications weeks beyond the acute coronavirus disease 2019 (COVID-19) infection is referred to as long COVID. Among the well-known long-term complications of COVID-19, myocardial damage is a frequently encountered side effect. Yet there is a lack of data for identifying high-risk patients who are more likely to develop long-term cardiovascular complications following COVID-19. Myocardial perfusion imaging (MPI) is the primary functional imaging modality in evaluating myocardial ischemia This study aimed to investigate the role of MPI in predicting myocardial ischemia in patients diagnosed with long COVID. Subjects were selected from eligible long COVID patients and control subjects without a prior history of COVID-19 who were referred to the nuclear medicine department for stress and rest single-photon emission computed tomography (SPECT) MPI. All participants' past medical records and clinical, and demographic characteristics were scanned. In addition, patients undergoing coronary angiography (CAG) following SPECT MPI were documented and patients with critical coronary stenosis were identified. Our results revealed that long COVID patients had higher rates of abnormal summed stress scores compared to the control subjects (p < 0.05). Additionally, serum CRP level, SPECT lung-to-heart ratio (LHR), and the presence of long COVID were independent predictors of ischemia. The presence of long COVID was the best predictor of ischemia among the aforementioned parameters (p < 0.001). Our data indicate that SPECT MPI provides comprehensive information on myocardial perfusion and left ventricular function in long COVID patients.

Body Mass Index Is Independently Associated with the Presence of Ischemia in Myocardial Perfusion Imaging.

Background and Objectives: Obesity has been linked to various cardiovascular risk factors, increased incidence of coronary artery disease, and myocardial perfusion defects. The aim of this study was to investigate if body mass index (BMI) and waist circumference (WC) were associated with myocardial perfusion defects. Materials and Methods: A total of 308 consecutive patients who had myocardial perfusion imaging (MPI) with single photon emission computed tomography (SPECT) and a complete medical record on file were studied retrospectively. Results: The median age was 69 (61–76) years, the BMI was 27.6 (24.4–30.7) kg/m2, and the WC was 110 (102–118) cm. Of the 308 patients, 239 patients (77.6%) had myocardial ischemia. A positive test for ischemia was more frequent in men compared to women (72 vs. 28%, p < 0.001). Within the male group, BMI and WC were not significantly different between the ischemia and non-ischemia groups. In contrast, within the female group, both BMI (30.2 vs. 27.1 kg/m2, p = 0.002) and WC (112 vs. 105.5 cm, p = 0.020) were significantly higher in the ischemia group. Multivariable logistic regression showed that male sex and BMI were the only two independent predictors of ischemia in our patient population. Conclusions: This study showed that BMI was an independent predictor of ischemia in our patient population.

The effect of coronavirus disease 2019 pneumonia on myocardial ischemia detected by single-photon emission computed tomography myocardial perfusion imaging.

ObjectiveWe aimed to examine the effects of COVID-19 pneumonia on cardiac ischemia detected by myocardial perfusion imaging with single-photon emission computed tomography myocardial perfusion imaging (SPECT-MPI) in patients presenting with chest pain and shortness of breath after recovery from COVID-19.Materials and methodPatients with a history of COVID-19 confirmed by reverse transcriptase-PCR test who underwent SPECT-MPI for the evaluation of ischemia with the complaints of chest pain and shortness of breath were screened for this study. Patients who underwent thorax CT during the acute period of the COVID-19 were included. Patients with and without pneumonia were determined based on computed tomographic criteria. The patients with a summed stress score of at least 4 on SPECT-MPI were considered to have abnormal MPI in terms of ischemia.ResultsA total of 266 patients were included in the study. Sixty-five (24%) patients had ischemia findings on SPECT-MPI. Thorax CT showed pneumonia in 152 (57%) patients, and the patients were divided into two groups as pneumonia and nonpneumonia. Abnormal SPECT-MPI scores, which represented myocardial ischemia, were higher in the pneumonia group. Multivariate logistic regression analyses showed that the presence of hyperlipidemia and pneumonia on CT increased the risk of ischemia on SPECT-MPI (OR, 2.08; 95% CI, 1.08–3.99; P-value = 0.029; and OR, 2.90; 95% Cl, 1.52–5.54; P-value = 0.001, respectively).ConclusionCOVID-19 pneumonia was identified as an independent predictor of ischemia on SPECT-MPI. Symptoms including chest pain and shortness of breath in patients who have had COVID-19 pneumonia may be attributed to coronary ischemia.

Exercise ECG testing in patients without known ischemic heart disease: predictors of ischemia of downstream vasodilator stress cardiac magnetic resonance

Abstract Background In routine clinical practice, patients with chest pain and suspected stable ischemic heart disease (SIHD) usually undergo an exercise ECG stress test (ExECG) for ischemia detection. However, since the sensitivity of this technique is relatively low, concerns exist that many patients could remain underdiagnosed. We intend to assess the clinical and ExECG predictors of ischemia on subsequent vasodilator stress cardiac magnetic resonance (vs-CMR) to help select which patients should undergo downstream testing after an initial ExECG. Material and methods We retrospectively included 197 patients without previous history of ischemic heart disease who underwent an ExECG and a subsequent vs-CMR in the year after this test and who didn't undergo a revascularization procedure in this time frame. Clinical, ExECG and vs-CMR variables were included in the registry. vs-CMR was considered positive if ischemia was evident in at least one myocardial segment on stress first-pass perfusion without concomitant necrosis on late gadolinium enhancement imaging. We performed univariate and multivariate analysis to check for the association of variables with the risk of ischemia on vs-CMR. Results Mean time from ExECG to vs-CMR was 88.69±84.32 days and 37 vs-CMR were positive for ischemia. Male sex, less exercise time, less % of maximum predicted exercise capacity, less maximum double product (heart rate x systolic blood pressure) and less double product reserve (DPR = maximum double product - basal double product) were associated with ischemia on vs-CMR on univariate analyses. However, the only independent predictors of ischemia on vs-CMR on multivariate binary logistic regression were male sex (HR 2.62 [CI 95%: 1.13–5.76], p=0.016) and less DPR (HR 0.90 [CI 95%: 0.84–0.97] per 1000 increase, p=0.006). The risk score derived from these two variables had a moderate predictive power (ROC curves, AUC 0.657, p=0.003). The best cut-off point for the DPR was 12400, as derived from the Youden index. It allowed stratification of the risk of ischemia on vs-CMR, which ranged from 9% in women with &amp;gt;12400 DPR, 18.8% in men with &amp;gt;12400 DPR, 24.1% in women with ≤12400 DPR to 42.9% in men with ≤12400 DPR (p=0.005, Figure 1). Conclusions Male sex and less double product reserve on ExECG can moderately predict the risk of ischemia on subsequent vs-CMR in patients presenting with chest pain and without previous SIHD. This can help select patients who benefit most from vs-CMR for diagnostic purposes. Funding Acknowledgement Type of funding sources: None. Figure 1

The Discriminatory Ability of Renalase and Biomarkers of Cardiac Remodeling for the Prediction of Ischemia in Chronic Heart Failure Patients With the Regard to the Ejection Fraction.

Background: Renalase has been implicated in chronic heart failure (CHF); however, nothing is known about renalase discriminatory ability and prognostic evaluation. The aims of the study were to assess whether plasma renalase may be validated as a predictor of ischemia in CHF patients stratified to the left ventricular ejection fraction (LVEF) and to determine its discriminatory ability coupled with biomarkers representing a range of heart failure (HF) pathophysiology: brain natriuretic peptide (BNP), soluble suppressor of tumorigenicity (sST2), galectin-3, growth differentiation factor 15 (GDF-15), syndecan-1, and cystatin C.Methods: A total of 77 CHF patients were stratified according to the LVEF and were subjected to exercise stress testing. Receiver operating characteristic curves were constructed, and the areas under curves (AUC) were determined, whereas the calibration was evaluated using the Hosmer-Lemeshow statistic. A DeLong test was performed to compare the AUCs of biomarkers.Results: Independent predictors for ischemia in the total HF cohort were increased plasma concentrations: BNP (p = 0.008), renalase (p = 0.012), sST2 (p = 0.020), galectin-3 (p = 0.018), GDF-15 (p = 0.034), and syndecan-1 (p = 0.024), whereas after adjustments, only BNP (p = 0.010) demonstrated predictive power. In patients with LVEF <45% (HFrEF), independent predictors of ischemia were BNP (p = 0.001), renalase (p < 0.001), sST2 (p = 0.004), galectin-3 (p = 0.003), GDF-15 (p = 0.001), and syndecan-1 (p < 0.001). The AUC of BNP (0.837) was statistically higher compared to those of sST2 (DeLong test: p = 0.042), syndecan-1 (DeLong: p = 0.022), and cystatin C (DeLong: p = 0.022). The AUCs of renalase (0.753), galectin-3 (0.726), and GDF-15 (0.735) were similar and were non-inferior compared to BNP, regarding ischemia prediction. In HFrEF patients, the AUC of BNP (0.980) was statistically higher compared to those of renalase (DeLong: p < 0.001), sST2 (DeLong: p < 0.004), galectin-3 (DeLong: p < 0.001), GDF-15 (DeLong: p = 0.001), syndecan-1 (DeLong: p = 0.009), and cystatin C (DeLong: p = 0.001). The AUC of renalase (0.814) was statistically higher compared to those of galectin-3 (DeLong: p = 0.014) and GDF-15 (DeLong: p = 0.046) and similar to that of sST2. No significant results were obtained in the patients with LVEF >45%.Conclusion: Plasma renalase concentration provided significant discrimination for the prediction of ischemia in patients with CHF and appeared to have similar discriminatory potential to that of BNP. Although further confirmatory studies are warranted, renalase seems to be a relevant biomarker for ischemia prediction, implying its potential contribution to ischemia-risk stratification.

CT-FFR vs a model of combined plaque characteristics for identifying ischemia: Results from CT-FFR CHINA trial

ObjectivesTo evaluate the diagnostic performance of fractional flow reserve (FFR) derived from coronary computed tomography angiography (CCTA; CT-FFR) and combined plaque characteristics for ischemia in different CCTA stenosis levels. MethodsThis clinical trial analyzed 317 patients with 30 %–90 % coronary stenosis in 366 vessels from 5 centers undergoing CCTA and invasive FFR. 366 vessels were assigned into < 50 % (nonobstructive) and ≥ 50 % (obstructive) stenosis groups. Lesion length (LL), plaque burden (PB), diameter stenosis (DS), volume ratio of plaque subcomponents < 30 HU (VR < 30HU), and high-risk features were analyzed. Logistic regression models were used to identify plaque characteristic predictors for lesion-specific ischemia in different stenosis grades. The area under receiver operating characteristics curve (AUC) of integrated plaque characteristics and CT-FFR were calculated and compared. ResultsIn < 50 % stenosis lesions, PB (OR: 1.296, p = 0.002), LL (OR:1.075, p = 0.020), and DS (OR:1.085, p = 0.031) were independent predictors of ischemia. In ≥ 50 % stenosis lesions, VR < 30HU (OR:1.031, p = 0.005) and DS (OR: 1.020, p = 0.044) were independent predictors for ischemia. AUC of plaque characteristic (VR < 30HU plus DS) for ischemia was 0.67 (95 % CI: 0.61–0.72) in ≥ 50 % stenosis level, which was significantly lower than CT-FFR (AUC=0.90; 95 % CI: 0.86–0.93) (p < 0.001). For lesions causing < 50 % stenosis, AUC of combined plaque model (VR < 30HU plus DS) was 0.88 (95 % CI: 0.80–0.95), equivalent to AUC of CT-FFR (AUC = 0.88; 95 % CI: 0.80–0.96; p = 0.957). ConclusionCT-FFR is a powerful functional assessment tool for both obstructive and nonobstructive diseases. However, for nonobstructive CAD confirmed by CCTA, a model of a combination of plaque characteristics could be a valuable alternative to CT-FFR.

CT-based total vessel plaque analyses improves prediction of hemodynamic significance lesions as assessed by fractional flow reserve in patients with stable angina pectoris

BackgroundCoronary stenosis and plaque evaluation by coronary computed tomography angiography (CTA) may contribute to identify hemodynamically relevant lesions. We evaluated the most stenotic lesion including plaques proximal to it versus a total vessel analyses combined with stenosis for ischemia. MethodsPatients scheduled for clinically indicated invasive coronary angiography (ICA) for suspected coronary artery disease underwent coronary CTA and ICA including fractional flow reserve (FFR) as part of the NXT trial (clinicaltrials.govNCT01757678). Stenoses were visually graded ≤50%, 51–70%, and >70% on coronary CTA. Semi-automated plaque analyses were performed using a proximal to the FFR pressure sensor location (including the most severe lesion to the coronary ostium) versus a total vessel (vessel diameter ≥2 mm) approach. Coronary stenosis and plaque parameters were evaluated for discrimination of ischemia by logistic regressions and combined models analyzed using receiver operating characteristics (ROC) with invasive FFR≤ 0.80 as reference standard. ResultsIn 254 patients, mean (±SD) age 64 (±10) years, 64% male, a coronary CTA stenosis >50% was present in 239 (49%) vessels. Invasive FFR was ≤0.80 in 100 (21%) vessels. Coronary stenosis severity and low-density non-calcified plaque (LD-NCP) volume were independent predictors of ischemia in the “proximal” and “total-vessel” analyses. Stenosis severity + total vessel LD-NCP assessment performed better than stenosis severity + proximal LD-NCP evaluation (Area under curve [AUC] (95%CI): 0.83 (0.78–0.87) vs 0.81 (0.76–0.86), p-value = 0.009), whereas stenosis severity + proximal LD-NCP performed better than stenosis alone (AUC (95%CI): 0.81 (0.76–0.86) vs 0.78 (0.73–0.83), p-value = 0.019). ConclusionAdding total vessel high-risk plaque volume to stenosis severity improves discrimination of ischemia in coronary CTA performed in patients with stable angina pectoris.

Dense calcium and lesion-specific ischemia: A comparison of CCTA with fractional flow reserve

Background and aimsStudies evaluating the relationship between dense coronary calcium (DC) and myocardial ischemia have had incongruent results. We sought to clarify whether DC, as detected by computed coronary tomographic angiography (CCTA), is an independent predictor of ischemia as measured by invasive fractional flow reserve (FFR). MethodsIn total, 249 (399 lesions) stable patients undergoing CCTA and invasive FFR were enrolled for this post-hoc analysis. DC was defined as plaque with ≥350 HU using quantification software, and ischemia was defined as FFR ≤0.80. We evaluated the relationship of dense calcium volume (DCV), lesion plaque volume (LPV), non-calcified plaque volume (NCV), and area stenosis (AS) with ischemia using logistic regression reporting odds ratios (OR) with 95% confidence intervals (95% CI). ResultsMean age was 63.0 ± 8.6 years, and 73 (29.3%) were female. Mean DCV was higher in lesions with FFR ≤0.80 (57.0 ± 54.7 mm3vs. 37.6 ± 49.5 mm3, [p < 0.001]). DCV and LPV were closely correlated (Pearson's coefficient = 0.49 [p < 0.001]). After adjustment for AS, LPV (OR 1.01, 95% CI 1.00–1.04, p < 0.001) but not DCV (OR 1.01, 95% CI 0.96–1.06, p = 0.69) was independently associated with ischemia. ConclusionsDense calcium is not an independent predictor of ischemia, but rather a marker of aggregate LPV, which in turn, is predictive of ischemia.

Value of resting echocardiographic findings and dobutamine stress echocardiography for diagnosing myocardial ischemia in patients with suspected angina pectoris.

We evaluated the diagnostic value of resting echocardiographic findings including total heart calcification (THC) score in combination with dobutamine stress echocardiography (DSE) for detection of myocardial ischemia. Altogether, 110 patients with suspected angina pectoris underwent resting echocardiography and DSE. On the basis of resting echocardiography, we determined the THC score, left anterior descending artery diastole-to-systole velocity ratio (LAD-DSVR), and positive myocardial velocity during isovolumic relaxation phase (VIVR ) detected by color-coded tissue Doppler imaging. Myocardial ischemia was diagnosed by a 25% or greater reduction in the internal diameter of major coronary vessels with impaired fractional flow reserve (FFR ≤0.80). DSE had excellent specificity (89%) but modest sensitivity (52%) for wall-motion abnormality (WMA) analysis. Multivariate analysis showed that THC score ≥2 (odds ratio and 95% confidence interval: 4.49 [2.29-10.6]; P=0.018), LAD-DSVR ≤1.5 (6.43 [1.39-20.3], P=0.019), and duration of positive VIVR ≥71msec (7.93 [3.72-12.1]; P<0.001) were independent predictors of ischemia. The combination of inducible WMA and THC score yielded significantly higher sensitivity for ischemia detection than the inducible WMA alone (80% vs. 52%, P=0.0008). Using receiver operating characteristics analyses, adding all three resting echocardiographic findings to clinical variables plus inducible WMA further improved prediction of ischemia (P=0.028). Integration of DSE and resting echocardiographic findings describing degree of heart calcification, impaired LAD flow, and extent of delayed ejection motion of the myocardium improves detection of coronary angiogram-based FFR-guided ischemia.

Asymmetric dimethylarginine is not a good predictor of ischemia using myocardial perfusion scintigraphy.

Asymmetric dimethylarginine (ADMA) plays role in the pathogenesis of coronary artery disease and related mortality and morbidity through a number of mechanisms. We hypothesized that plasma ADMA levels would be increased in the presence of reversible ischemia as measured by GATED single photon emission computed tomography (SPECT) myocardial perfusion scintigraphy (MPS). Fasting i.v. blood samples were drawn before testing. All patients underwent 99mTc-sestamibi GATED SPECT MPS with a one-day stress-rest protocol; the images were visually analyzed. Post-stress GATED parameters, including ejection fraction, end systolic and end diastolic volumes, and automatic stress defect scores, were recorded. The plasma ADMA levels were higher in the ischemic group than in the non-ischemic group (0.46 ± 0.19 vs. 0.40 ± 0.15; P = 0.016). Plasma ADMA levels (odds ratio [OR] = 13.5; 95% confidence interval [CI] = 1.7-109.01; P = 0.015) and sex (OR = 2.49, 95% CI = 1.18-5.26; P = 0.017) were independent predictors of ischemia. There was no linear correlation between plasma ADMA levels and both the GATED SPECT and stress test parameters. Our data support the hypothesis that increased baseline ADMA levels are independently related with the presence of reversible ischemia.

Resistin predicts ischemia in myocardial perfusion scintigraphy.

Aim: Resistin plays a role in the pathogenesis of coronary artery disease and is related to mortality and morbidity through a number of mechanisms. We hypothesize that plasma resistin levels are increased in the presence of ischemia, as measured by GATED single- photon emission computed tomography myocardial perfusion scintigraphy (SPECT MPS), in comparison with nonischemic subjects. Fasting intravenous blood samples of patients were drawn before a stress test. An ELISA kit was used for the assays. All patients underwent a technetium 99m-sestamibi GATED SPECT MPS study with a 1-day stress-rest protocol. Images were analyzed visually and patients were assessed as ischemic or nonischemic. Resistin levels were presented as medians (25th-75th percentiles) and were compared using the Mann-Whitney U test. Plasma resistin levels were higher in the ischemic group (n = 47) than in the nonischemic group (n = 67) [9.04 pmol/L (6.27-11.8 μmol/L) vs. 3.56 μmol/L (0.39-7.93 pnol/L), respectively; P < 0.001). We showed that plasma resistin levels (OR = 1.26, 95% CI: 1.13-1.41; P < 0.001) and METs (OR = 0.82, 95% CI: 0.70-0.92; P = 0.021) were independent predictors ofischemia. No linear correlation was found between plasma resistin levels and GATED SPECT or stress test parameters. Increased baseline resistin levels are independently related to presence of ischemia but are not related to the extent or severity of ischemia, or other functional parameters such as poststress ejection fraction, end systolic, and end diastolic volumes.

Prevalence of ischemia on myocardial perfusion scintigraphy of pre-and postmenopausal women.

BackgroundIn postmenopausal women, the presence of risk factors for coronary artery disease (CAD) increases. However, the difference in prevalence of ischemia between pre- and postmenopausal women with multiple risk factors for CAD has not been well established.ObjectivesTo compare the prevalence of ischemia on Tc99m-sestamibi myocardial perfusion scintigraphy (MPS) in pre-and postmenopausal women, and to evaluate whether menopause can be considered an independent risk predictor of ischemia in women with multiple risk factors for CAD.MethodsThis study retrospectively assessed 500 MPS of pre- and postmenopausal women with multiple risk factors for CAD. Statistical analysis was performed by using Fisher exact test and univariate and multivariate analysis, a p value ≤ 0.05 being considered significant.ResultsPostmenopausal women represented 55.9% of the sample; 83.3% were hypertensive; 28.9%, diabetic; 32.1%, smokers; 25%, obese; 61.2% had high cholesterol levels; and 34.3% had known CAD. Postmenopausal women were more often hypertensive, diabetic and dyslipidemic, and had lower functional capacity on exercise testing (p = < 0.005). The presence of ischemia on MPS did not significantly differ between the pre- and postmenopausal groups (p = 0.395). The only variable associated with ischemia on MPS was known CAD (p = 0.004).ConclusionThe results suggest that, in women with multiple risk factors for CAD, menopause was not an independent predictor of ischemia on MPS. Those data support the idea that the investigation of ischemia via MPS in women with multiple risk factors for CAD should begin prior to menopause.

Lipid Levels as Predictors of Silent Myocardial Ischemia in a Type 2 Diabetic Population in Havana

Silent myocardial ischemia is frequent in type 2 diabetics, therefore, symptoms cannot be relied upon for diagnosis and followup in these patients. Various studies relate blood lipid levels to cardiovascular diseases, and several authors describe certain lipoproteins as independent predictors of ischemia. Identify blood lipid levels that predict silent myocardial ischemia in a type 2 diabetic population in Havana. From May 2005 through May 2009, assessment was done of 220 asymptomatic type 2 diabetics in ten polyclinics in Havana using laboratory tests and Single-Photon Emission-Computed Tomography, synchronized with electrocardiogram, known as gated SPECT (gSPECT). Coronary angiography was used for confirmation when gSPECT detected ischemia. Patients were classified into two groups: gSPECT positive and gSPECT negative. Descriptive statistics (mean and standard deviation) were calculated for all variables and mean comparison tests were conducted. Classification trees were developed relating lipid values to gSPECT results, identifying optimal cutoff points for their use as indicators of silent myocardial ischemia in the total study population and for each sex separately. GSPECT found silent myocardial ischemia in 29.1% of those examined, and 68.4% of angiograms found multivessel disease. gSPECT-positive diabetics had higher levels of total cholesterol, LDL, and triglycerides (p < 0.05). HDL levels were lower in this group (p < 0.05). Classification trees showed optimal cutoff points, indicators for silent ischemia, for: HDL ≤44 mg/dL, LDL >119.9 mg/dL, and triglycerides >107.2 mg/d; 80.4% of diabetics with these HDL and triglyceride values had ischemia. HDL was the most important normalized variable when the entire population was analyzed. Analysis by sex showed a greater percentage of silent ischemia in men (33.3%) than in women (24.8%). The most important normalized variables were LDL of >100.8 mg/dL for men and HDL of ≤44 mg/dL for women. A considerable percentage of the study population had silent myocardial ischemia. Type 2 diabetics with ischemia had higher levels of total cholesterol, LDL and triglycerides. HDL levels were significantly lower in these patients. The association of low HDL with high triglycerides was a strong indicator of myocardial ischemia in type 2 diabetics without clinical cardiovascular signs. KEYWORDS Lipids, type 2 diabetes, silent myocardial ischemia, decision trees, diagnostic imaging, Single-Photon Emission-Computed Tomography, cardiac-gated SPECT, early detection, Cuba.

Predictive value of procalcitonin for bowel ischemia and necrosis in bowel obstruction

To our knowledge, the predictive value of procalcitonin for bowel strangulation has been evaluated in only 2 experimental studies that had conflicting results. The objective of this study was to evaluate the value of procalcitonin for early diagnosis of intestinal ischemia and necrosis in acute bowel obstruction. We performed a prospective study of 242 patients with small- or large-bowel obstructions in 2005. A total of 100 patients who underwent operation were divided into groups according to the presence of ischemia (reversible and irreversible) and necrosis, respectively, as follows: ischemia (n = 35) and nonischemia groups (n = 65) and necrosis (n = 22) and nonnecrosis groups (n = 78). Data analyzed included age, sex, vital signs, symptoms, clinical findings, white blood cell count, base deficit, metabolic acidosis, procalcitonin levels on presentation, the time between symptom onset and arrival at the emergency department and the time between arrival and operation, and the cause of the obstruction. Procalcitonin levels were greater in the ischemia than the nonischemia group (9.62 vs 0.30 ng/mL; P = .0001) and in the necrosis than the non-necrosis group (14.53 vs 0.32 ng/mL; P = .0001). Multivariate analysis identified procalcitonin as an independent predictor of ischemia (P = .009; odds ratio, 2.252; 95% confidence interval, 1.225-4.140) and necrosis (P = .005; odds ratio, 2.762; 95% confidence interval, 1.356-5.627). Using receiver operating characteristic (ROC) curve analysis, the area under the curve (AUC) of procalcitonin for ischemia and necrosis was 0.77 and 0.87, respectively. A high negative predictive value for ischemia and necrosis of procalcitonin levels <0.25 ng/mL (83% and 95%, respectively) and a positive predictive value of procalcitonin >1 ng/mL were identified (95% and 90%, respectively). Procalcitonin on presentation is very useful for the diagnosis or exclusion of intestinal ischemia and necrosis in acute bowel obstruction and could serve as an additional diagnostic tool to improve clinical decision-making.

Epicardial adipose tissue volume and coronary artery calcium to predict myocardial ischemia on positron emission tomography-computed tomography studies

BackgroundThere appears to be an association of epicardial adipose tissue (EAT) with coronary artery disease (CAD) and its risk factors. EAT is assumed to influence CAD development by altering vasomotor tone and via toxic paracrine effects. The relationship of EAT to myocardial perfusion has not been studied. MethodsQuantification of EAT and CAC was performed on positron emission tomography/computed tomography (PET/CT) studies in 45 subjects (77% intermediate pre-test probability of CAD) with mild-moderate myocardial ischemia (5-14% perfusion defect, n = 23), severe ischemia (≥15% defect, n = 22) and a control group with no ischemia matched for CAD risk factors (n = 52). ResultsEAT volume showed a better correlation with myocardial ischemia than total CAC (r = .47 vs r = .28, P < .01). EAT volume increased significantly from the control group to subjects with mild-moderate and severe ischemia (96.9, 124.5, and 143.9 cm3, P < .01 for both ischemia groups vs controls). Total mean CAC was significantly higher in the severe ischemia group (676.3) than in control group (229.4) (P < .01). Multivariable logistic regression analyses showed that EAT volume was, but CAC was not, a significant predictor of ischemia after adjustment for age, sex, body mass index, and each other. EAT volume was a better predictor of ischemia than total CAC [area under the curve (AUC): .764 vs .6291, P = .04]. The combination of EAT + CAC (AUC = .7694) did not improve over EAT volume alone (P = .57). ConclusionsIn this study, EAT volume assessed by CT was an independent predictor of ischemia on PET, and outperformed CAC score in a CAD naïve population at intermediate pre-test probability of disease.

Determinants of a positive exercise test in patients admitted with acute non-infarct chest pain

Background and objectives. Some patients with suspected unstable angina show ischemia at the exercise treadmill test despite having been medically stabilized. The objective of this study was to determine clinical characteristics predicting a positive exercise treadmill test in patients with suspected unstable angina after medical stabilization. Methods. In 885 hospitalized patients with medically stabilized unstable angina, the relationship between the result of the pre-discharge exercise treadmill test and clinical characteristics was studied. Results. Mean age was 62±9 years and 668 (75%) were male. Exercise test was positive (chest pain and/or ST depression ≥1 mm) in 288 patients (33%). Univariate analysis showed the following associated with ischemia at the exercise test: male gender (56% vs. 20%, P<0.001), diabetes mellitus (41% vs. 31%, P=0.009), previous unstable angina (41% vs. 24%, P=0.001), previous stable angina (44% vs. 30%, P<0.001), previous coronary artery bypass grafting (43% vs. 31%, P=0.043), peripheral artery disease (45% vs. 31%) and progressive angina (55% vs. 31%, P<0.001). Multivariate analysis showed the following as independent predictors of ischemia: male gender (OR=2.25), diabetes (OR=4.12), previous unstable angina (OR=3.89), previous stable angina (OR=3.74) and progressive angina (OR=4.05). Conclusions. In patients with suspected unstable angina, after medical stabilization: (1) the exercise treadmill test is positive in one-third of cases; (2) male gender, diabetes, previous angina (unstable and stable) and progressive angina are independent predictors of ischemia.

Which variable of stenosis severity best describes the significance of an isolated left anterior descending coronary artery lesion? Correlation between quantitative coronary angiography, intracoronary Doppler measurements and high dose dipyridamole echocardiography.

This study sought to investigate the angiographic or intracoronary Doppler variables of stenosis severity that best correlate with the results of dipyridamole echocardiography. Quantitative coronary angiography and intracoronary Doppler flow velocity assessments are the commonly used techniques for the objective identification of significant coronary artery stenosis. Thirty patients with an isolated lesion of the left anterior descending coronary artery (LAD) were studied by means of on-line quantitative coronary arteriography, intracoronary Doppler flow velocity measurements and dipyridamole echocardiography 6 months after percutaneous transluminal coronary angioplasty. The quantitative arteriographic analyses were performed on-line; post-stenotic Doppler flow velocities were measured at baseline and after adenosine infusion. Angiographic and Doppler measurements were compared with the corresponding dipyridamole echocardiographic data and analyzed by discriminant analysis. The dipyridamole echocardiographic response was positive in 11 patients (37%). The best cutoff values for predicting an abnormal echocardiographic response were 1) stenotic flow reserve of 2.8 (p = 0.0001); 2) 59% diameter stenosis (p = 0.0001); 3) minimal lumen diameter of 1.35 mm (p = 0.001); 4) coronary flow reserve of 2.0 (p = 0.0002); and 5) maximal peak velocity of 60 cm/s during hyperemia (p = 0.04). Multivariate analysis identified stenotic flow reserve as the only independent predictor of ischemia during dipyridamole echocardiography. Stenotic flow reserve is the variable that best describes the functional significance of an isolated LAD lesion, and a value of 2.8 is the best predictor of a positive dipyridamole echocardiographic response. Furthermore, angiographic variables of stenosis severity relate to echocardiographic test results better than intracoronary Doppler variables.

The Outcome of Exercise Tolerance Testing is Dependent on the Time of the Day

BackgroundAlthough exercise testing is commonly used to identify patients with an increased risk for ischemic events and to evaluate drug therapy, no reports have clearly addressed whether a daily variation exists in exercise test parameters. Therefore the present study was undertaken, analyzing the effects of the time of the day on exercise test parameters in a large population of cardiovascular patients.MethodsWe compared the responses of bicycle exercise testing in 6674 patients, mean age 60 years, referred for evaluation of coronary artery disease. The daily variation was tested by grouping the exercise variables into four 2‐hour periods. Further logistic regression analysis was used to assess predictors for the occurrence of ischemia.ResultsSignificant time of the day differences were found both at rest and in their changes to peak exercise for heart rate (P &lt; 0.0001 and P &lt; 0.0004), systolic blood pressure (P &lt; 0.0001 and P &lt; 0.0003), and diastolic blood pressure (P &lt; 0.004 and P &lt; 0.0001). Furthermore, ischemia occurred significantly more often during the afternoon intervals (P &lt; 0.009) and time of the day was an independent predictor of ischemia during exercise testing.ConclusionThe present study demonstrates that several exercise parameters show a significant daytime variation. The time of the day is an independent predictor for the occurrence of ischemia during an exercise test, and the detection of ischemia may be enhanced by performing exercise tests in the afternoon.