A New Anatomic Score for Prognosis After Cardiac Catheterization in Patients with Previous Bypass Surgery

Prognostic Value of Coronary Computed Tomography Angiography in Coronary Artery Bypass Graft Patients Systematic Review and Meta-Analysis

We sought to assess the prognostic value of coronary computed tomographic angiography (CCTA) in patients with coronary artery bypass graft (CABG) by meta-analysis. MEDLINE, Embase, Cochrane Central Register of Controlled Trials, and Scopus were searched for relevant original articles published up to July 2021. CCTA prognostic studies enrolling patients with CABG were screened and included if outcomes included all-cause mortality or major adverse cardiac events. Maximally adjusted hazard ratios (HRs) were extracted for CCTA-derived prognostic factors. HRs were log-transformed and pooled across studies using the DerSimonian-Laird random-effects model and statistical heterogeneity was assessed using the I² statistic. Of 1,576 screened articles, 4 retrospective studies fulfilled all inclusion criteria. Collectively, a total of 1,809 patients with CABG underwent CCTA (mean [SD] age 67.0 [8.5] years across 3 studies, 81.5% male across 4 studies). Coronary artery disease severity and revascularization were categorized using 2 models: unprotected coronary territories and coronary artery protection score. The pooled HRs from the random-effects models using the most highly adjusted study estimate were 3.64 (95% confidence interval 2.48 to 5.34, I² = 57.8%, p <0.001; 4 studies) and 4.85 (95% confidence interval 3.17 to 7.43, I² = 39.9%, p <0.001; 2 studies) for unprotected coronary territories and coronary artery protection score, respectively. In conclusion, in a limited number of studies, CCTA is an independent predictor of adverse events in patients with CABG. Larger studies using uniform models and endpoints are needed.

Validation of the Intermountain Risk Score and Get with the Guidelines-Heart Failure Score in predicting mortality

Objective

The Intermountain Risk Score (IMRS) was evaluated for validation as a mortality predictor and compared with the American Heart Association’s Get With The Guidelines—Heart Failure (GWTG-HF) risk score in a rural heart failure (HF) population.

Background

IMRS predicts mortality in general populations using common, inexpensive laboratory tests, patient age and sex, but requires validation in patients with HF.

Methods

Individuals were selected from the GWTG-HF registry at Essentia Health. This included consecutive HF inpatients age ≥18 years admitted July 2017–June 2019. IMRS was calculated using sex-specific weightings of the complete blood count, basic metabolic profile, and age.

Results

A total of 703 individuals (mean age: 74.12, 44.38% female) were studied. The 30-day IMRS predicted 30-day mortality for both sexes (females n=312: OR=1.19 (95% CI 1.08 to 1.32) per +1, p<0.001; males n=391: OR=1.23 (CI 1.12 to 1.36) per +1, p<0.001). The GWTG-HF risk score (only available in n=300, 42.7%) was independent of IMRS for 30-day mortality (OR=1.11 (CI 1.06 to 1.16) per +1, p<0.001). Using thresholds in bivariate modelling, IMRS (high vs low risk, OR=8.25 (CI 2.19 to 31.09), p=0.002) and the GWTG-HF score (tertile 3 vs 1: OR=2.18 (CI 0.84 to 5.68), p=0.11) independently predicted mortality. In multivariable analyses including covariables, IMRS (high vs low risk: OR=6.69 (CI 1.75 to 25.60), p=0.005) and the GWTG-HF score (tertile 3 vs 1: OR=2.62 (CI 0.96 to 7.12), p=0.06) remained predictors of mortality. Results were similar for 1-year mortality.

Conclusions

The IMRS and GWTG-HF scores predicted mortality of patients with HF in a large rural healthcare system. Future study of these scores as initial clinical risk estimators for evaluating their utility in improving patient health outcomes and increasing cost effectiveness is warranted.

Practical laboratory-based clinical decision tools and associations with short-term bleeding and mortality outcomes

BACKGROUND

The red cell distribution width (RDW) predicts mortality in numerous populations. The Intermountain Risk Scores (IMRS) predict patient outcomes using laboratory measurements including RDW. Whether the RDW or IMRS predicts in-hospital outcomes is unknown.

METHODS

The predictive abilities of RDW and two IMRS formulations (the complete blood count [CBC] risk score [CBC-RS] or full IMRS using CBC plus the basic metabolic profile) were studied among percutaneous coronary intervention patients at Intermountain (males: N = 6007, females: N = 2165). Primary endpoints were a composite bleeding outcome and in-hospital mortality.

RESULTS

IMRS predicted the composite bleeding endpoint (females: χ² = 47.1, odds ratio [OR] = 1.13 per +1 score, p < 0.001; males: χ² = 108.7, OR = 1.13 per +1 score, p < 0.001) more strongly than RDW (females: χ² = 1.6, OR = 1.04 per +1%, p = 0.20; males: χ² = 11.2, OR = 1.09 per +1%, p < 0.001). For in-hospital mortality, RDW was predictive in females (χ² = 4.3, OR = 1.13 per +1%, p = 0.037) and males (χ² = 4.4, OR = 1.11 per +1%, p = 0.037), but IMRS was profoundly more predictive (females: χ² = 35.5, OR = 1.36 per +1 score, p < 0.001; males: χ² = 72.9, OR = 1.40 per+1 score, p < 0.001). CBC-RS was more predictive than RDW but not as powerful as IMRS.

CONCLUSIONS

The IMRS, the CBC-RS, and RDW predict in-hospital outcomes. Risk score-directed personalization of in-hospital clinical care should be studied.

Validation of the Coronary Artery Bypass Graft SYNTAX Score (Synergy Between Percutaneous Coronary Intervention With Taxus) as a Prognostic Marker for Patients With Previous Coronary Artery Bypass Graft Surgery After Percutaneous Coronary Intervention

BACKGROUND

The efficacy and prognosis of percutaneous coronary intervention (PCI) as secondary revascularization in patients with previous coronary artery bypass graft surgery remain uncertain.

METHODS AND RESULTS

We retrospectively evaluated 434 consecutive patients with previous coronary artery bypass graft surgery hospitalized for PCI between 2004 and 2011 (men 84%, age 71 (interquartile range, 66-76) years) and calculated the coronary artery bypass graft Synergy Between Percutaneous Coronary Intervention With Taxus score (CSS) before (baseline CSS) and after PCI (post-PCI CSS). Patients were divided into 2 groups based on median post-PCI CSS: low-score (≤23; n=217) and high-score groups (>23; n=217). Major adverse cardiovascular events (MACE) were defined as the composite of cardiovascular death, myocardial infarction, and unplanned repeat revascularization for myocardial ischemia. The median baseline and post-PCI CSS were 30 (interquartile range, 21-40) and 23 (interquartile range, 14.5-33.5), respectively. During a median follow-up of 69 months, the prevalence of MACE and cardiac death differed significantly between the 2 post-PCI CSS groups (MACE: low, 13.8%; high, 28.6%; P<0.001; cardiac death: low, 6.2%; high, 16.7%; P=0.002). In multivariable analysis, the high post-PCI CSS divided by the median was associated with substantially greater cumulative MACE (hazard ratio, 2.09; 95% confidence interval, 1.31-3.34; P=0.002) and cardiac death (hazard ratio, 2.02; 95% confidence interval, 1.03-3.98; P=0.042) compared with the low post-PCI CSS. Net reclassification improvement analysis revealed that post-PCI CSS resulted in significantly improved prediction of MACE and cardiac death compared with baseline CSS.

CONCLUSIONS

In this external validation study, the CSS was a potential prognostic factor after subsequent PCI, even for previous coronary artery bypass graft surgery patients.

Frequency, Predictors, and Implications of Abnormal Blood Pressure Responses During Dobutamine Stress Echocardiography

BACKGROUND

It is not known whether abnormal blood pressure (BP) responses during dobutamine stress echocardiography (DSE) are associated with abnormal test results, nor if such results indicate obstructive coronary artery disease (CAD). We sought to define the frequency of abnormal BP responses during DSE and their impact on accuracy of test results.

METHODS AND RESULTS

We studied 21 949 patients who underwent DSE at Mayo Clinic, Rochester, MN, grouped by peak systolic BP achieved during the test. We also analyzed a subgroup who underwent coronary angiography within 30 days after positive DSE. The positive predictive value of DSE was calculated for each BP group. Patients with hypertensive response (n=1905; 9%) were more likely to have positive DSE than those with normal (n=19 770; 90%) or hypotensive (n=274; 1%) BP responses (32% versus 21% versus 23%, respectively; P<0.0001). Angiography, performed in 1126 patients, showed obstructive CAD (≥50% stenosis) in 814 patients and severe CAD (≥70% stenosis) in 708 patients. Positive predictive value of DSE was similar for patients who had hypertensive and normal BP responses (69% versus 73%; P=0.3), considering 50% stenosis cut point. The proportion of severe CAD (≥70% stenosis) was lower in patients who had hypertensive response compared with those who had normal BP response (54% versus 65%; P=0.005).

CONCLUSIONS

Patients with hypertensive response during DSE are more likely to have stress-induced myocardial ischemia compared with those with normal or hypotensive BP responses but are not more likely to have false-positive DSE results. They are, however, less likely to have higher grade or multivessel CAD.

Race and Sex Differences in QRS Interval and Associated Outcome Among Patients with Left Ventricular Systolic Dysfunction

Background

Prolonged QRS duration is associated with increased mortality among heart failure patients, but race or sex differences in QRS duration and associated effect on outcomes are unknown.

Methods and Results

We investigated QRS duration and morphology among 2463 black and white patients with heart failure and left ventricular ejection fraction ≤35% who underwent coronary angiography and 12‐lead electrocardiography at Duke University Hospital from 1995 through 2011. We used multivariable Cox regression models to assess the relationship between QRS duration and all‐cause mortality and investigate race‐QRS and sex‐QRS duration interaction. Median QRS duration was 105 ms (interquartile range [IQR], 92–132) with variation by race and sex (P<0.001). QRS duration was longest in white men (111 ms; IQR, 98–139) followed by white women (108 ms; IQR, 92–140), black men (100 ms; IQR, 91–120), and black women (94 ms; IQR, 86–118). Left bundle branch block was more common in women than men (24% vs 14%) and in white (21%) versus black individuals (12%). In black patients, there was a 16% increase in risk of mortality for every 10 ms increase in QRS duration up to 112 ms (hazard ratio, 1.16; 95% CI, 1.07, 1.25) that was not present among white patients (interaction, P=0.06).

Conclusions

Black individuals with heart failure had a shorter QRS duration and more often had non‐left bundle branch block morphology than white patients. Women had left bundle branch block more commonly than men. Among black patients, modest QRS prolongation was associated with increased mortality.

Improvement in the predictive ability of the Intermountain Mortality Risk Score by adding routinely collected laboratory tests such as albumin, bilirubin, and white cell differential count

Background:

The Intermountain Mortality Risk Score (IMRS), a sex-specific mortality-prediction metric, has proven to be effective in various populations. IMRS is comprised of the complete blood count (CBC), basic metabolic panel (BMP), and age. Whether the addition of factors from the comprehensive metabolic panel (CMP) and white blood cell (WBC) differential count improves risk stratification is unknown.

Methods:

Patients with baseline complete metabolic panel (CMP) and IMRS measurements were randomly assigned (60%/40%) to independent derivation (n=84,913) and validation (n=56,584) populations. A sex-specific risk score based on IMRS methods was computed in the derivation population using adjusted multivariable regression weights from all significant and noncollinear CMP [expanded IMRS (eIMRS)] and, when available, WBC differential components (eIMRS+diff).

Results:

Age averaged 67±16 years for females and 67±15 years for males. Receiver operator characteristic (ROC) c-statistics for 30-day death showed marked improvement for the eIMRS compared to the IMRS in both females [0.895 (0.882, 0.908) vs. 0.865 (0.850, 0.880)] and males [0.861 (0.847, 0.876) vs. 0.824 (0.807, 0.841)]. These results persisted for 1-year death: females [0.854 (0.847, 0.862) vs. 0.828 (0.819, 0.836)] and males [0.835 (0.826, 0.844) vs. 0.796 (0.789, 0.808)]. In addition, the eIMRS significantly improved risk reclassification. Further precision was seen when WBC differential components were included.

Conclusions:

The addition of the CMP components to the IMRS improved risk prediction. WBC differential also improved risk score predictive ability. These results suggest that the eIMRS may function even better than IMRS as a tool in patient care, risk-adjustment, and clinical research settings for predicting outcomes.

Perioperative outcomes after on- and off-pump coronary artery bypass grafting

Although numerous reports describe the results of off-pump coronary artery bypass grafting (CABG) at specialized centers and in select patient populations, it remains unclear how off-pump CABG affects real-world patient outcomes. We conducted a large, multicenter observational cohort study of perioperative death and morbidity in on-pump (ON) versus off-pump (OFF) CABG. We reviewed Veterans Affairs Surgical Quality Improvement Program data for all patients (N=65,097) who underwent isolated CABG from October 1997 through April 2011 (intention-to-treat data were available from 2005 onward). The primary outcome was perioperative (30-day or in-hospital) death; the secondary outcomes were perioperative stroke, dialysis dependence, reoperation for bleeding, mechanical circulatory support, myocardial infarction, ventilator support ≥ 48 hr, and mediastinitis. Propensity scores calculated from age, 17 preoperative risk factors, and year of surgery were used to match 8,911 OFF with 26,733 ON patients. In the complete cohort, compared with the ON patients (n=53,468), the OFF patients (n=11,629) had less perioperative death (2.02% vs 2.53%, P=0.0012) and lower incidences of all morbidities except perioperative myocardial infarction. In the matched cohort, perioperative death did not differ significantly between OFF and ON patients (1.94% vs 2.28%, P=0.06), but the OFF group had lower incidences of all morbidities except for perioperative myocardial infarction and mediastinitis. A subgroup intention-to-treat analysis yielded similar but smaller outcome differences between the ON and OFF groups. Off-pump CABG might be associated with decreased operative morbidity but did not affect operative death, compared with on-pump CABG. Future studies should examine the effect of off-pump CABG on long-term outcomes.

Outcomes following percutaneous coronary intervention and coronary artery bypass grafting surgery in Chinese, South Asian and White patients with acute myocardial infarction: administrative data analysis

Background

Little is known on whether there are ethnic differences in outcomes following percutaneous coronary intervention (PCI) and coronary artery bypass grafting surgery (CABG) after acute myocardial infarction (AMI). We compared 30-day and long-term mortality, recurrent AMI, and congestive heart failure in South Asian, Chinese and White patients with AMI who underwent PCI and CABG.

Methods

Hospital administrative data in British Columbia (BC), Canada were linked to the BC Cardiac Registry to identify all patients with AMI who underwent PCI (n = 4729) or CABG (n = 1687) (1999–2003). Ethnicity was determined from validated surname algorithms. Logistic regression for 30-day mortality and Cox proportional-hazards models were adjusted for age, sex, socio-economic status, severity of coronary disease, comorbid conditions, time from AMI to a revascularization procedure and distance to the nearest hospital.

Results

Following PCI, Chinese had higher short-term mortality (Odds Ratio (OR): 2.36, 95% CI: 1.12-5.00; p = 0.02), and South Asians had a higher risk for recurrent AMI (OR: 1.34, 95% CI: 1.08-1.67, p = 0.007) and heart failure (OR 1.81, 95% CI: 1.00-3.29, p = 0.05) compared to White patients. Risk of heart failure was higher in South Asian patients who underwent CABG compared to White patients (OR (95% CI) = 2.06 (0.92-4.61), p = 0.08). There were no significant differences in mortality following CABG between groups.

Conclusions

Chinese and South Asian patients with AMI and PCI or CABG had worse outcomes compared to their White counterparts. Further studies are needed to confirm these findings and investigate potential underlying causes.

The CABG SYNTAX Score - an angiographic tool to grade the complexity of coronary disease following coronary artery bypass graft surgery: from the SYNTAX Left Main Angiographic (SYNTAX-LE MANS) substudy

AIMS

The SYNTAX Score (SXscore) has established itself as an important prognostic tool in patients undergoing percutaneous coronary intervention (PCI). A limitation of the SXscore is the inability to differentiate outcomes in patients who have undergone prior coronary artery bypass graft (CABG) surgery. The CABG SXscore was devised to address this limitation.

METHODS AND RESULTS

In the SYNTAX-LE MANS substudy 115 patients with unprotected left main coronary artery disease (isolated or associated with one, two or three-vessel disease) treated with CABG were prospectively assigned to undergo a 15-month coronary angiogram. An independent core laboratory analysed the baseline SXscore prior to CABG. The 15-month CABG SXscore was calculated by a panel of three interventional cardiologists. The CABG SXscore was calculated by determining the standard SXscore in the "native" coronary vessels ("native SXscore") and deducting points based on the importance of the diseased coronary artery segment (Leaman score) that have a functioning bypass graft anastomosed distally. Points relating to intrinsic coronary disease, such as bifurcation disease or calcification, remain unaltered. The mean 15-month CABG SXscore was significantly lower compared to the mean baseline SXscore (baseline SXscore 31.6, SD 13.1; 15-month CABG SXscore 21.2, SD 11.1; p<0.001). Reproducibility analyses (kappa [k] statistics) indicated a substantial agreement between CABG SXscore measurements (k=0.70; 95% CI [0.50-0.90], p<0.001), with the points deducted to calculate the CABG SXscore the most reproducible measurement (k=0.74; 95% CI [0.53-0.95], p<0.001). Despite the limited power of the study, four-year outcome data (Kaplan-Meier curves) demonstrated a trend towards reduced all-cause death (9.1% vs. 1.8%, p=0.084) and death/CVA/MI (16.4% vs. 7.0%, p=0.126) in the low compared to the high CABG SXscore group.

CONCLUSIONS

In this pilot study the calculation of the CABG SXscore appeared feasible, reproducible and may have a long-term prognostic role in patients with complex coronary disease undergoing surgical revascularisation. Validation of this new scoring methodology is required.

Performing coronary artery bypass grafting off-pump may compromise long-term survival in a veteran population

BACKGROUND

There are ample data regarding the short-term outcomes of on-pump and off-pump coronary artery bypass grafting (CABG), but little is known about the long-term survival associated with these approaches.

METHODS

Using the Veterans Affairs (VA) Continuous Improvement in Cardiac Surgery Program, we identified all VA patients (n = 65,097) who underwent primary isolated CABG from October 1997 to April 2011. The primary outcome measure was all-cause mortality. Age, 17 preoperative risk factors, and year of operation were used to calculate propensity scores for each patient. A greedy-match algorithm using the propensity scores matched 8,911 off-pump with 26,733 on-pump patients. Survival functions were estimated by the Kaplan-Meier method and compared by using the log-rank test.

RESULTS

In the complete cohort, off-pump was used in 11,629 of 65,097 (17.9%) operations. For the matched cohort, the median follow-up was 6.7 years (interquartile range, 3.72 to 9.35 years). Risk-adjusted mortality did not differ significantly between the off-pump and on-pump groups at 1 year (4.67% vs 4.78%; risk ratio [RR], 0.98; 95% confidence interval [CI], 0.88 to 1.09) or 3 years (9.21% vs 8.89%; RR, 1.04; 95% CI, 0.96 to 1.12). However, risk-adjusted mortality was higher in the off-pump group at 5 years (14.47% vs 13.45%; RR, 1.08; 95% CI 1.02 to 1.15) and 10 years (25.18% vs 23.57%; RR, 1.07; 95% CI, 1.03 to 1.12). Overall, the hazard ratio for off-pump vs on-pump was 1.06 (95% CI, 1.00 to 1.13; p = 0.04).

CONCLUSIONS

Off-pump CABG may be associated with decreased long-term survival. Further studies are needed to identify the reasons behind this finding.

Prognostic utility of BCIS myocardial jeopardy score for classification of coronary disease burden and completeness of revascularization

Several coronary disease scoring systems have been developed to predict procedural risk during revascularization. Many vary in complexity, do not specifically account for myocardium at risk, and are not applicable across all patient subsets. The British Cardiovascular Intervention Society myocardial jeopardy score (BCIS-JS) addresses these limitations and is applicable to all patients, including those with coronary artery bypass grafts or left main stem disease. We assessed the prognostic relevance of the BCIS-JS in patients undergoing percutaneous coronary intervention (PCI). A total of 663 patients who underwent PCI with previous left ventricular function assessment were retrospectively assessed for inclusion, incorporating 221 with previous coronary artery bypass grafting. Blinded observers calculated the BCIS-JS, before (BCIS-JS(PRE)) and after (BCIS-JS(POST)) PCI, using the revascularization index (RI) (RI = [BCIS-JS(PRE) - BCIS-JS(POST)]/BCIS-JS(PRE)), quantifying the extent of revascularization, 1 indicating full revascularization and 0 indicating no revascularization. The primary end point all-cause mortality, tracked via the Office of National Statistics. A total of 660 patients were included (66 ± 10.7 years), with 43 deaths (6.5%) occurring during 2.6 ± 1.1 years after PCI. All-cause mortality was directly related to BCIS-JS(PRE) (hazard ratio [HR] 2.96, 95% confidence interval [CI] 1.71 to 5.15, p = 0.001) and BCIS-JS(POST) (HR 4.02, 95% CI 2.41 to 6.68, p = 0.001). A RI of <0.67 was associated with increased mortality compared to a RI of ≥0.67 (HR 4.13, 95% CI 1.91 to 8.91, p = 0.0001). On multivariate analysis, a RI <0.67 (HR 1.99, 95% CI 1.03 to 3.87, p = 0.04), left ventricular dysfunction (HR 2.03, 95% CI 1.25 to 3.30, p = 0.004) and renal impairment (HR 3.75, 95% CI 1.48 to 8.64, p = 0.005) were independent predictors of mortality. In conclusion, the BCIS-JS predicts mortality after PCI and can assess the degree of revascularization, with more complete revascularization conferring a survival advantage in the medium term.

Validation of the BCIS-1 myocardial jeopardy score using cardiac magnetic resonance perfusion imaging

The recently described angiographic BCIS-1 Myocardial Jeopardy Score (BCIS-JS) provides a semi-quantitative estimate of the extent of coronary artery disease (CAD). It is simple to use and applicable to all patients including those with bypass grafts. Our objective was to validate the BCIS-JS by evaluating its correlation with myocardial ischaemic burden and its accuracy at predicting a prognostic ischaemic threshold. Seventy-five patients with angina and known or suspected CAD referred for coronary angiography prospectively underwent high-resolution CMR perfusion imaging. There was good correlation between the BCIS-JS and myocardial ischaemic burden: r = 0·75, P<0·0001. Area under the ROC curve for BCIS-JS to detect ≥12% myocardial ischaemic burden was 0·87 (95% CI 0·78-0·96). BCIS-JS ≥6 predicted ≥12% myocardial ischaemic burden with a sensitivity of 68% and a specificity of 91%. The BCIS-JS correlates well with myocardial ischaemic burden. A BCIS-JS ≥6 predicts the prognostically important ischaemic threshold of 12% with high specificity. These findings demonstrate that the BCIS-JS has functional relevance and support its utility for classification of CAD burden in clinical trials and in clinical practice.

Validation of dynamic 3-dimensional whole heart magnetic resonance myocardial perfusion imaging against fractional flow reserve for the detection of significant coronary artery disease

OBJECTIVES

The goal of this study was to determine the diagnostic accuracy of dynamic 3-dimensional (3D) whole heart myocardial perfusion cardiovascular magnetic resonance (CMR) against invasively determined fractional flow reserve (FFR) and to establish the correlation between myocardium at risk defined by using the invasive Duke Jeopardy Score (DJS) and noninvasive 3D whole heart myocardial perfusion CMR.

BACKGROUND

3D whole heart myocardial perfusion CMR overcomes the limited spatial coverage of conventional two-dimensional perfusion CMR methods and allows estimation of the extent of ischemia. The method has shown good diagnostic accuracy for the detection of coronary artery disease (CAD) as defined by using quantitative coronary angiography. However, quantitative coronary angiography does not provide a functional assessment of CAD as available from pressure wire-derived FFR. In the catheter laboratory, the DJS can complement FFR to estimate the myocardium at risk.

METHODS

Fifty-three patients referred for angiography underwent rest and adenosine stress 3D whole heart myocardial perfusion CMR at 3-T. Perfusion was scored visually on a patient and coronary territory basis, and ischemic burden was calculated by quantitative segmentation of the volume of hypoenhancement. FFR was measured in vessels with ≥50% severity stenosis and an FFR <0.75 considered as hemodynamically significant. The DJS was calculated from the coronary angiograms to quantify the myocardium at risk.

RESULTS

FFR was measured in 64 of 159 coronary vessels, and 39 had an FFR <0.75. Sensitivity, specificity, and diagnostic accuracy of CMR for the detection of significant CAD were 91%, 90%, and 91%, on a patient basis and 79%, 92%, and 88%, respectively, by coronary territory. There was a strong correlation between the DJS and ischemic burden on CMR (p < 0.0001; Pearson's r = 0.82).

CONCLUSIONS

3D whole heart myocardial perfusion CMR accurately detects functionally significant CAD as defined by using FFR and provides an assessment of ischemic burden in agreement with the invasive DJS. The accurate detection of significant CAD combined with an estimation of ischemic burden by using 3D myocardial perfusion CMR holds promise for noninvasive guidance of therapy and risk stratification of patients with CAD.

Perioperative mortality in diabetic patients undergoing coronary artery bypass graft surgery

OBJECTIVE

To investigate the risk factors for in-hospital death in diabetic patients undergoing isolated Coronary Artery Bypass Grafting (CABG).

METHODS

We conducted a retrospective study with 305 consecutive diabetic patients undergoing CABG in the Division of Cardiovascular Surgery of our institution from April 2004 to April 2010. Univariate analysis for categorical variables was performed with the chi-square or Fisher's exact test, as appropriate. Potential risk factors with p <0.05 in the univariate analysis were included in the multivariate analysis, which was performed by backward logistic regression. Values of p <0.05 were considered statistically significant.

RESULTS

The study population had a mean age of 61.44 years (± 9.81) and 65.6% (n=200) were male. The in-hospital mortality rate was 11.8% (n=36). The following independent risk factors for death were identified: on-pump CABG (OR 6.15, 95% CI 1.57 to 24.03, P=0.009) and low cardiac output in the postoperative period (OR 34.17, 95% CI 10.46 to 111.62, P <0.001). The use of internal thoracic artery (ITA) was an independent protective factor for death (OR 0.27, 95% CI 0.08 to 0.093, P=0.038).

CONCLUSION

This study identified the following independent risk factors for death after CABG: on-pump CABG and low cardiac output syndrome. The use of ITA was an independent protective factor.

Linking empirical estimates of body burden of environmental chemicals and wellness using NHANES data

Biomonitoring of industrial chemicals in human tissues and fluids has shown that all people carry a "body burden" of synthetic chemicals. Although measurement of an environmental chemical in a person's tissues/fluids is an indication of exposure, it does not necessarily mean the exposure concentration is sufficient to cause an adverse effect. Since humans are exposed to multiple chemicals, there may be a combination effect (e.g., additive, synergistic) associated with low-level exposures to multiple classes of contaminants, which may impact a variety of organ systems. The objective of this research is to link measures of body burden of environmental chemicals and a "holistic" measure of wellness. The approach is demonstrated using biomonitoring data from the National Health and Nutrition Examination Surveys (NHANES). Forty-two chemicals were selected for analysis based on their detection levels. Six biological pathway-specific indices were evaluated using groups of chemicals associated with each pathway. Five of the six pathways were negatively associated with wellness. Three non-zero interaction terms were detected which may provide empirical evidence of crosstalk across pathways. The approach identified five of the 42 chemicals from a variety of classes (metals, pesticides, furans, polycyclic aromatic hydrocarbons) as accounting for 71% of the weight linking body burden to wellness. Significant interactions were detected indicating the effect of smoking is exacerbated by body burden of environmental chemicals. Use of a holistic index on both sides of the exposure-health equation is a novel and promising empirical "systems biology" approach to risk evaluation of complex environmental exposures.

The Intermountain Risk Score (including the red cell distribution width) predicts heart failure and other morbidity endpoints

AIMS

The complete blood count (CBC) and basic metabolic profile are common, low-cost blood tests, which have previously been used to create and validate the Intermountain Risk Score (IMRS) for mortality prediction. Mortality is the most definitive clinical endpoint, but medical care is more easily applied to modify morbidity and thereby prevent death. This study tested whether IMRS is associated with clinical morbidity endpoints.

METHODS AND RESULTS

Patients seen for coronary angiography (n = 3927) were evaluated using a design similar to a genome-wide association study. The Bonferroni correction for 102 tests required a P-value of ≤ 4.9 × 10⁻⁴ for significance. A second set of angiography patients (n = 10 413) was used to validate significant findings from the first patient sample. In the first patient sample, IMRS predicted heart failure (HF) (P(trend) = 1.6 × 10(-26)), coronary disease (P(trend) = 2.6 × 10(-11)), myocardial infarction (MI) (P(trend) = 3.1 × 10(-25)), atrial fibrillation (P(trend) = 2.5 × 10(-20)), and chronic obstructive pulmonary disease (P(trend) = 4.7 × 10⁻⁴). Even more, IMRS predicted HF readmission [hazard ratio (HR) = 2.29/category, P(trend) = 1.2 × 10⁻⁶), incident HF (HR = 1.88/category, P(trend) = 0.02), and incident MI (HR = 1.56/category, P(trend) = 4.7 × 10⁻⁴). These findings were verified in the second patient sample.

CONCLUSION

Intermountain Risk Score, a predictor of mortality, was associated with morbidity endpoints that often lead to mortality. Further research is required to fully characterize its clinical utility, but its low-cost CBC and basic metabolic profile composition may make it ideal for initial risk estimation and prevention of morbidity and mortality. An IMRS web calculator is freely available at http://intermountainhealthcare.org/IMRS.

Exceptional mortality prediction by risk scores from common laboratory tests

BACKGROUND

Some components of the complete blood count and basic metabolic profile are commonly used risk predictors. Many of their components are not commonly used, but they might contain independent risk information. This study tested the ability of a risk score combining all components to predict all-cause mortality.

METHODS

Patients with baseline complete blood count and basic metabolic profile measurements were randomly assigned (60%/40%) to independent training (N = 71,921) and test (N = 47,458) populations. A third population (N = 16,372) from the Third National Health and Nutrition Examination Survey and a fourth population of patients who underwent coronary angiography (N = 2558) were used as additional validation groups. Risk scores were computed in the training population for 30-day, 1-year, and 5-year mortality using age- and sex-adjusted weights from multivariable modeling of all complete blood count and basic metabolic profile components.

RESULTS

Area under the curve c-statistics were exceptional in the training population for death at 30 days (c = 0.90 for women, 0.87 for men), 1 year (c = 0.87, 0.83), and 5-years (c = 0.90, 0.85) and in the test population for death at 30 days (c = 0.88 for women, 0.85 for men), 1 year (c = 0.86, 0.82), and 5 years (c = 0.89, 0.83). In the test, the Third National Health and Nutrition Examination Survey, and the angiography populations, risk scores were highly associated with death (P <.001), and thresholds of risk significantly stratified all 3 populations.

CONCLUSION

In large patient and general populations, risk scores combining complete blood count and basic metabolic profile components were highly predictive of death. Easily computed in a clinical laboratory at negligible incremental cost, these risk scores aggregate baseline risk information from both the popular and the underused components of ubiquitous laboratory tests.

Clinical characteristics associated with poor long-term survival among patients with diabetes mellitus undergoing saphenous vein graft interventions

BACKGROUND

Limited data exist on the long-term outcomes among diabetic patients undergoing saphenous vein graft (SVG) interventions. Thus, the baseline clinical factors associated with long-term adverse events in these patients are less known.

METHODS

Accordingly, we analyzed 1,160 consecutive patients (37.7% with diabetes) undergoing SVG interventions from the Duke Cardiovascular Disease Database (1990-2003). Cox proportional hazards modeling was used to identify predictors of long-term death in diabetic patients. The most significant model predictors were then used to construct a decision tree providing unadjusted Kaplan-Meier survival estimates at a median follow-up of 4 years.

RESULTS

At median follow-up of 4 years, death (33.3% vs 18.1%, P < .0001; unadjusted hazard ratio 1.98, 95% CI 1.64-2.38) and death or myocardial infarction (49.6% vs 32.9%, unadjusted hazard ratio 1.71, 95% CI 1.462.00) were significantly higher in patients with diabetes mellitus compared with those without it. In patients with diabetes undergoing SVG interventions, a simple clinical decision algorithm, based on the most significant model predictors, demonstrated that 88% of patients without heart rate >80 beat/min, congestive heart failure, renal insufficiency, or hypertension survived after SVG intervention at median follow-up of 4 years. In contrast, none of the few patients with all these 4 factors survived at follow-up (100% mortality).

CONCLUSIONS

Compared with patients without diabetes, diabetic patients undergoing SVG intervention have significantly worse long-term outcomes with one third dying at median follow-up of 4 years. We provide a simple decision tool that allows stepwise risk-stratification using baseline factors in diabetic patients undergoing SVG interventions and identify 4 risk factors associated with extremely poor long-term survival in this cohort.

[Coronary artery surgery in patients with diabetes mellitus]

Diabetes mellitus is present in 25-30% of patients undergoing coronary artery bypass grafts surgery. Early and late post-operative prognoses are different for the diabetic patient. Coronary artery bypass grafts are indicated in 2 or more vessel lesions, but it can also be preferred to percutaneous angioplasty in 1-vessel lesions, when this is the anterior descending artery or there is a great area under ischemia. Diabetic candidates to renal transplant must be investigated and revascularized pre-operatively, if necessary. Morbidity is greater in these patients, mainly due to respiratory, renal and cerebral complications and wound infections. Intensive care unit and hospital length of stay are more prolonged, but there is not increased early mortality. Diabetes mellitus represents an independent risk factor for late graft failure and mortality from cardiac and general causes. Although under an increased risk, coronary artery surgery results in better quality of life and late survival in the diabetic patients with severe coronary artery disease, as compared to medical treatment and percutaneous coronary angioplasty, specially in those who use insulin and when internal thoracic arterial grafts are implanted.

A systematic review of randomized trials comparing revascularization rate and graft patency of off-pump and conventional coronary surgery

OBJECTIVE

Although many trials have been conducted to evaluate the benefits of off-pump coronary surgery, few have concentrated on graft patency. We sought to evaluate the impact of off-pump surgery on completeness of revascularization and graft patency compared with conventional surgery.

METHODS

A systematic literature search was undertaken of all randomized trials of off-pump coronary surgery in MEDLINE, EMBASE, the Cochrane Library Controlled Trials Register, the National Research Register, and abstracts from major conferences.

RESULTS

In total, 132 publications were identified. From this number, we excluded 43 without a conventional surgery arm and 80 that did not evaluate graft patency. One trial was excluded for selective angiography and one abstract was excluded because of insufficient information. A total of 7 trials were eligible for overview. On initial analysis, the relative risk of graft patency in off-pump coronary surgery compared with conventional surgery was 0.959 (95% confidence interval 0.936-0.983; P = .001). The analysis was repeated after excluding one specific trial because of clinical and statistical heterogeneity (chi2(6) = 27.78; P < .001), and a relative risk of 0.953 (95% confidence interval 0.927-0.980; P = .001) was obtained with no further evidence of heterogeneity (chi2(5) = 5.35; P = .374). In 5 trials that included the mean number of grafts performed per arm, the standardized mean difference in revascularization comparing off-pump with conventional surgery was -0.164 (-0.286 to -0.043; P = .008).

CONCLUSION

In a meta-analysis of randomized trials, patients undergoing off-pump coronary surgery had a lower rate of revascularization and lower graft patency than did patients undergoing conventional coronary surgery.

Clinical correlates of long-term mortality after percutaneous interventions of saphenous vein grafts

BACKGROUND

Increasing number of patients undergo percutaneous intervention of saphenous vein grafts (SVGs). However, the clinical factors associated with long-term mortality after SVG interventions are currently less known. Accordingly, the goal of present study was to evaluate clinical correlates of long-term mortality and to develop a simple bedside tool for risk stratification in patients undergoing SVG interventions.

METHODS

We analyzed 1019 patients undergoing SVG interventions from the Duke Cardiovascular Disease Database (1986-2003). Cox proportional hazards model was used to identify baseline variables associated with long-term mortality, and the model variables were then used to construct a nomogram for survival probability at 4 years.

RESULTS

At a median follow-up of 4 years, 24% of those undergoing SVG interventions died (interquartile range 2-7 years). Independent correlates of death at follow-up on multivariable analysis included presenting heart rate (hazard ratio [HR] 1.02, 95% CI 1.01-1.03), diabetes (HR 1.73, 95% CI 1.37-2.18), presenting heart failure (HR 1.62, 95% CI 1.27-2.06), age (per 10-year increase, HR 1.29, 95% CI 1.13-1.46), peripheral vascular disease (HR 1.59, 95% CI 1.23-2.04), renal insufficiency (HR 2.01, 95% CI 1.36-2.97), patent internal mammary graft (HR 0.67, 95% CI 0.53-0.86), body mass index < or = 25 kg/m2 (HR 0.91, 95% CI 0.85-0.97), carotid bruit (HR 1.44, 95% CI 1.12-1.85), S3 ventricular gallop (HR 1.83, 95% CI 1.11-3.03), and hypertension (HR 1.38, 95% CI 1.04-1.83) (c-index 0.83). Bootstrap validation confirmed excellent internal validity of the model (mean c-index 0.84, 95% CI 0.80-0.85).

CONCLUSION

Long-term survival after SVG intervention is poor, with one fourth of patients dying at median follow-up of 4 years. The nomogram developed using the model variables provides a method for clinicians to advise patients undergoing SVG interventions regarding their long-term prognosis, thereby enhancing discharge and long-term follow-up planning and setting up of realistic expectations.

Impact of internal mammary artery conduit on long-term outcomes after percutaneous intervention of saphenous vein graft

BACKGROUND

The influence of an internal mammary artery (IMA) graft on long-term outcomes after percutaneous saphenous vein graft (SVG) intervention is currently unknown.

METHODS AND RESULTS

To examine the impact of IMA on outcomes in patients undergoing SVG interventions, we analyzed 2119 patients from the Duke Cardiovascular Disease Database (1986-2003) with prior coronary artery bypass surgery undergoing cardiac catheterization who had at least 1 SVG graft. Patients were categorized into 4 groups: group I, SVG intervention and patent IMA; group II, no SVG intervention and patent IMA; group III, SVG intervention without patent IMA; and group IV, no SVG intervention without patent IMA. At a median follow-up of 4.8 years (interquartile range, 2.1 to 8.8 years), adjusted survival rates in groups I, II, III, and IV were 72.8%, 72.3%, 64.5%, and 58.9%, respectively. Multivariate Cox proportional hazards modeling showed similar survival for groups I and II (P=0.63) and for groups III and IV (P=0.33). The presence of IMA graft was related to lower long-term mortality (adjusted hazard ratio [HR], 0.69; 95% CI, 0.58 to 0.82), whereas SVG intervention was not associated with long-term mortality (adjusted HR, 0.94; 95% CI, 0.81 to 1.10). In contrast, the adjusted event-free rates for nonfatal myocardial infarction were lower in the SVG intervention groups (groups I and III) than in the non-SVG intervention groups (groups II and IV) (HR for SVG intervention versus no SVG intervention, 3.19; 95% CI, 2.18 to 4.66), with the presence of patent IMA conferring no significant benefit on this outcome (HR, 1.37; 95% CI, 0.91 to 2.08).

CONCLUSIONS

In patients undergoing SVG interventions, survival, but not nonfatal myocardial infarction, is favorably influenced by the presence of patent IMA. In contrast, SVG intervention had no measurable survival benefit but was associated with an increased risk of nonfatal myocardial infarction.