Use of bio-informatics assessment schema (BIAS) to improve diagnosis and prognosis of myocardial perfusion data: results from the NHLBI-sponsored women's ischemia syndrome evaluation (WISE).

BACKGROUND: We introduce an algorithmic approach to optimize diagnostic and prognostic value of gated cardiac single photon emission computed tomography (SPECT) and magnetic resonance (MR) myocardial perfusion imaging (MPI) modalities in women with suspected myocardial ischemia. The novel approach: bio-informatics assessment schema (BIAS) forms a mathematical model utilizing MPI data and cardiac metrics generated by one modality to predict the MPI status of another modality. The model identifies cardiac features that either enhance or mask the image-based evidence of ischemia. For each patient, the BIAS model value is used to set an appropriate threshold for the detection of ischemia. METHODS: Women (n=130), with symptoms and signs of suspected myocardial ischemia, underwent MPI assessment for regional perfusion defects using two different modalities: gated SPECT and MR. To determine perfusion status, MR data were evaluated qualitatively (MRIQL) and semi-quantitatively (MRISQ) while SPECT data were evaluated using conventional clinical criteria. Evaluators were masked to results of the alternate modality. These MPI status readings were designated "original". Two regression models designated "BIAS" models were generated to model MPI status obtained with one modality (e.g., MRI) compared with a second modality (e.g., SPECT), but importantly, the BIAS models did not include the primary Original MPI reading of the predicting modality. Instead, the BIAS models included auxiliary measurements like left ventricular chamber volumes and myocardial wall thickness. For each modality, the BIAS model was used to set a progressive threshold for interpretation of MPI status. Women were then followed for 38±14 months for the development of a first major adverse cardiovascular event [MACE: CV death, nonfatal myocardial infarction (MI) or hospitalization for heart failure]. Original and BIAS-augmented perfusion status were compared in their ability to detect coronary artery disease (CAD) and for prediction of MACE. RESULTS: Adverse events occurred in 14 (11%) women and CAD was present in 13 (10%). There was a positive correlation of maximum coronary artery stenosis and BIAS score for MRI and SPECT (P<0.001). Receiver operator characteristic (ROC) analysis was conducted and showed an increase in the area under the curve of the BIAS-augmented MPI interpretation of MACE vs. the original for MRISQ (0.78 vs. 0.54), MRIQL (0.78 vs. 0.64), SPECT (0.82 vs. 0.63) and the average of the three readings (0.80±0.02 vs. 0.60±0.05, P<0.05). CONCLUSIONS: Increasing values of the BIAS score generated by both MRI and SPECT corresponded to the increasing prevalence of CAD and MACE. The BIAS-augmented detection of ischemia better predicted MACE compared with the Original reading for the MPI data for both MRI and SPECT.

AMG145, a monoclonal antibody against proprotein convertase subtilisin kexin type 9, significantly reduces lipoprotein(a) in hypercholesterolemic patients receiving statin therapy: an analysis from the LDL-C Assessment with Proprotein Convertase Subtilisin Kexin Type 9 Monoclonal Antibody Inhibition Combined with Statin Therapy (LAPLACE)-Thrombolysis in Myocardial Infarction (TIMI) 57 trial.

BACKGROUND: Lipoprotein(a) [Lp(a)] is an emerging risk factor for cardiovascular disease. Currently, there are few available therapies to lower Lp(a). We sought to evaluate the impact of AMG145, a monoclonal antibody against proprotein convertase subtilisin kexin type 9 (PCSK9), on Lp(a). METHODS AND RESULTS: As part of the LDL-C Assessment With PCSK9 Monoclonal Antibody Inhibition Combined With Statin Therapy (LAPLACE)-Thrombolysis in Myocardial Infarction (TIMI) 57 trial, 631 patients with hypercholesterolemia receiving statin therapy were randomized to receive AMG145 at 1 of 3 different doses every 2 weeks or 1 of 3 different doses every 4 weeks versus placebo. Lp(a) and other lipid parameters were measured at baseline and at week 12. Compared with placebo, AMG145 70 mg, 105 mg, and 140 mg every 2 weeks reduced Lp(a) at 12 weeks by 18%, 32%, and 32%, respectively (P<0.001 for each dose versus placebo). Likewise, AMG145 280 mg, 350 mg, and 420 mg every 4 weeks reduced Lp(a) by 18%, 23%, and 23%, respectively (P<0.001 for each dose versus placebo). The reduction in Lp(a) correlated with the reduction in low-density lipoprotein cholesterol (ρ=0.33, P<0.001). The effect of AMG145 on Lp(a) was consistent regardless of age, sex, race, history of diabetes mellitus, and background statin regimen. Patients with higher levels of Lp(a) at baseline had larger absolute reductions but comparatively smaller percent reductions in Lp(a) with AMG145 compared with those with lower baseline Lp(a) values. CONCLUSIONS: AMG145 significantly reduces Lp(a), by up to 32%, among subjects with hypercholesterolemia receiving statin therapy, offering an additional, complementary benefit beyond robust low-density lipoprotein cholesterol reduction with regard to a patient's atherogenic lipid profile.

Economic outcomes of treatment strategies for type 2 diabetes mellitus and coronary artery disease in the Bypass Angioplasty Revascularization Investigation 2 Diabetes trial.

BACKGROUND: The economic outcomes of clinical management strategies are important in assessing their value to patients. METHODS AND RESULTS: Bypass Angioplasty Revascularization Investigation 2 Diabetes (BARI 2D) randomized patients with type 2 diabetes mellitus and angiographically documented, stable coronary disease to strategies of (1) prompt revascularization versus medical therapy with delayed revascularization as needed to relieve symptoms and (2) insulin sensitization versus insulin provision. Before randomization, the physician declared whether coronary artery bypass grafting or percutaneous coronary intervention would be used if the patient were assigned to revascularization. We followed 2005 patients for medical utilization and costs and assessed the cost-effectiveness of these management strategies. Medical costs were higher for revascularization than medical therapy, with a significant interaction with the intended method of revascularization (P<0.0001). In the coronary artery bypass grafting stratum, 4-year costs were $80 900 for revascularization versus $60 600 for medical therapy (P<0.0001). In the percutaneous coronary intervention stratum, costs were $73 400 for revascularization versus $67 800 for medical therapy (P<0.02). Costs also were higher for insulin sensitization ($71 300) versus insulin provision ($70 200). Other factors that significantly (P<0.05) and independently increased cost included insulin use and dose at baseline, female sex, white race, body mass index > or =30, and albuminuria. Cost-effectiveness based on 4-year data favored the strategy of medical therapy over prompt revascularization and the strategy of insulin provision over insulin sensitization. Lifetime projections of cost-effectiveness showed that medical therapy was cost-effective compared with revascularization in the percutaneous coronary intervention stratum ($600 per life-year added) with high confidence. Lifetime projections suggest that revascularization may be cost-effective in the coronary artery bypass grafting stratum ($47 000 per life-year added) but with lower confidence. CONCLUSIONS: Prompt coronary revascularization significantly increases costs among patients with type 2 diabetes mellitus and stable coronary disease. The strategy of medical therapy (with delayed revascularization as needed) appears to be cost-effective compared with the strategy of prompt coronary revascularization among patients identified a priori as suitable for percutaneous coronary intervention.

Trends in quality of care for patients with acute myocardial infarction in the National Registry of Myocardial Infarction from 1990 to 2006.

BACKGROUND: Trends in the use of guideline-based treatment for acute myocardial infarction (AMI) as well as its association with patient outcomes have not been summarized in a large, longitudinal study. Furthermore, it is unknown whether gender-, race-, and age-based care disparities have narrowed over time. METHODS AND RESULTS: Using the National Registry of Myocardial Infarction database, we analyzed 2,515,106 patients with AMI admitted to 2,157 US hospitals between July 1990 and December 2006 to examine trends overall and in select subgroups of guideline-based admission, procedural, and discharge therapy use. The contribution of temporal improvements in acute care therapies to declines in in-hospital mortality was examined using logistic regression analysis. From 1990 to 2006, the use of all acute guideline-recommended therapies administered rose significantly for patients with ST-segment elevation myocardial infarction and patients with non-ST-segment myocardial infarction but remained below 90% for most therapies. Cardiac catheterization and percutaneous coronary intervention use increased in patients with ST-segment elevation myocardial infarction and patients with non-ST-segment myocardial infarction, whereas coronary bypass surgery use declined in both groups. Despite overall care improvements, women, blacks, and patients > or =75 years old were significantly less likely to receive revascularization or discharge lipid-lowering therapy relative to their counterparts. Temporal improvements in acute therapies may account for up to 37% of the annual decline in risk for in-hospital AMI mortality. CONCLUSION: Adherence to American Heart Association/American College of Cardiology practice guidelines has improved care of patients with AMI and is associated with significant reductions in in-hospital mortality rates. However, persistent gaps in overall care as well as care disparities remain and suggest the need for ongoing quality improvement efforts.

Importance of socioeconomic status as a predictor of cardiovascular outcome and costs of care in women with suspected myocardial ischemia. Results from the National Institutes of Health, National Heart, Lung and Blood Institute-sponsored Women's Ischemia Syndrome Evaluation (WISE).

BACKGROUND: For women, who are more likely to live in poverty, defining the clinical and economic impact of socioeconomic factors may aid in defining redistributive policies to improve healthcare quality. METHODS: The NIH-NHLBI-sponsored Women's Ischemia Syndrome Evaluation (WISE) enrolled 819 women referred for clinically indicated coronary angiography. This study's primary end point was to evaluate the independent contribution of socioeconomic factors on the estimation of time to cardiovascular death or myocardial infarction (MI) (n = 79) using Cox proportional hazards models. Secondary aims included an examination of cardiovascular costs and quality of life within socioeconomic subsets of women. RESULTS: In univariable models, socioeconomic factors associated with an elevated risk of cardiovascular death or MI included an annual household income <$20,000 (p = 0.0001), <9th grade education (p = 0.002), being African American, Hispanic, Asian, or American Indian (p = 0.016), on Medicaid, Medicare, or other public health insurance (p < 0.0001), unmarried (p = 0.001), unemployed or employed part-time (p < 0.0001), and working in a service job (p = 0.003). Of these socioeconomic factors, income (p = 0.006) remained a significant predictor of cardiovascular death or MI in risk-adjusted models that controlled for angiographic coronary disease, chest pain symptoms, and cardiac risk factors. Low-income women, with an annual household income <$20,000, were more often uninsured or on public insurance (p < 0.0001) yet had the highest 5-year hospitalization and drug treatment costs (p < 0.0001). Only 17% of low-income women had prescription drug coverage (vs. >or=50% of higher-income households, p < 0.0001), and 64% required >or=2 anti-ischemic medications during follow-up (compared with 45% of those earning >or=$50,000, p < 0.0001). CONCLUSIONS: Economic disadvantage prominently affects cardiovascular disease outcomes for women with chest pain symptoms. These results further support a profound intertwining between poverty and poor health. Cardiovascular disease management strategies should focus on policies that track unmet healthcare needs and worsening clinical status for low-income women.

Layer of protection analysis for reactive chemical risk assessment.

Reactive chemical hazards have been a significant concern for the chemical process industries (CPI). Without sufficient control and mitigation of chemical reaction hazards, reactive incidents have led to severe consequences, such as release of flammable and toxic materials, fires and explosions, and threats to human lives, properties, and the environment. Consequence of reactive hazards can be well understood through calorimetric testing and computational techniques. However, risks of incidents caused by reactive chemicals have not been well addressed due partly to sparse failure frequency data. In this paper, the semi-quantitative layer of protection analysis (LOPA) approach is used to estimate reactive chemical risk, and the probabilities or frequencies of failure scenarios are addressed. Using LOPA, reactive risks can be evaluated with respect to predefined criteria, and the effectiveness of risk reduction measures can be assessed. The hydroxylamine (HA) production system is employed as a case study to demonstrate the application of LOPA to reactive chemical risk assessment.

The economic burden of angina in women with suspected ischemic heart disease: results from the National Institutes of Health--National Heart, Lung, and Blood Institute--sponsored Women's Ischemia Syndrome Evaluation.

BACKGROUND: Coronary angiography is one of the most frequently performed procedures in women; however, nonobstructive (ie, < 50% stenosis) coronary artery disease (CAD) is frequently reported. Few data exist regarding the type and intensity of resource consumption in women with chest pain after coronary angiography. METHODS AND RESULTS: A total of 883 women referred for coronary angiography were prospectively enrolled in the National Institutes of Health--National Heart, Lung, and Blood Institute--sponsored Women's Ischemia Syndrome Evaluation (WISE). Cardiovascular prognosis and cost data were collected. Direct (hospitalizations, office visits, procedures, and drug utilization) and indirect (out-of-pocket, lost productivity, and travel) costs were estimated through 5 years of follow-up. Among 883 women, 62%, 17%, 11%, and 10% had nonobstructive and 1-vessel, 2-vessel, and 3-vessel CAD, respectively. Five-year cardiovascular death or myocardial infarction rates ranged from 4% to 38% for women with nonobstructive to 3-vessel CAD (P < 0.0001). Five-year rates of hospitalization for chest pain occurred in 20% of women with nonobstructive CAD, increasing to 38% to 55% for women with 1-vessel to 3-vessel CAD (P < 0.0001). The volume of repeat catheterizations or angina hospitalizations was 1.8-fold higher in women with nonobstructive versus 1-vessel CAD after 1 year of follow-up (P < 0.0001). Drug treatment was highest for those with nonobstructive or 1-vessel CAD (P < 0.0001). The proportion of costs for anti-ischemic therapy was higher for women with nonobstructive CAD (15% versus 12% for 1-vessel to 3-vessel CAD; P = 0.001). For women with nonobstructive CAD, average lifetime cost estimates were $767,288 (95% CI, $708,480 to $826,097) and ranged from $1,001,493 to $1,051,302 for women with 1-vessel to 3-vessel CAD (P = 0.0003). CONCLUSIONS: Symptom-driven care is costly even for women with nonobstructive CAD. Our lifetime estimates for costs of cardiovascular care identify a significant subset of women who are unaccounted for within current estimates of the economic burden of coronary heart disease.

Medical costs and quality of life 10 to 12 years after randomization to angioplasty or bypass surgery for multivessel coronary artery disease.

BACKGROUND: Coronary bypass surgery (CABG) and angioplasty (PTCA) have been compared in several randomized trials, but data about long-term economic and quality-of-life outcomes are limited. METHODS AND RESULTS: Cost and quality-of-life data were collected prospectively from 934 patients who were randomized in the Bypass Angioplasty Revascularization Investigation (BARI) and followed up for 10 to 12 years. CABG had 53% higher costs initially, but the gap closed to <5% during the first 2 years; after 12 years, the mean cumulative cost of CABG patients was 123,000 dollars versus 120,750 dollars for PTCA, yielding a cost-effectiveness ratio of 14,300 dollars/life-year added. CABG patients experienced significantly greater improvement in their physical functioning for the first 3 years but not in later follow-up. Recurrent angina substantially reduced all quality-of-life measures throughout follow-up. Cumulative costs were significantly higher among patients with diabetes, heart failure, and comorbid conditions and among women; costs also were increased by angina, by the number of revascularization procedures, and among patients who died. CONCLUSIONS: Early differences between CABG and PTCA in costs and quality of life were no longer significant at 10 to 12 years of follow-up. CABG was cost-effective as compared with PTCA for multivessel disease.

Prognosis in women with myocardial ischemia in the absence of obstructive coronary disease: results from the National Institutes of Health-National Heart, Lung, and Blood Institute-Sponsored Women's Ischemia Syndrome Evaluation (WISE).

BACKGROUND: We previously reported that 20% of women with chest pain but without obstructive coronary artery disease (CAD) had stress-induced reduction in myocardial phosphocreatine-adenosine triphosphate ratio by phosphorus-31 nuclear magnetic resonance spectroscopy (abnormal MRS), consistent with myocardial ischemia. The prognostic implications of these findings are unknown. METHODS AND RESULTS: Women referred for coronary angiography for suspected myocardial ischemia underwent MRS handgrip stress testing and follow-up evaluation. These included (1) n=60 with no CAD/normal MRS, (2) n=14 with no CAD/abnormal MRS, and (3) n=352 a reference group with CAD. Cardiovascular events were death, myocardial infarction, heart failure, stroke, other vascular events, and hospitalization for unstable angina. Cumulative freedom from events at 3 years was 87%, 57%, and 52% for women with no CAD/normal MRS, no CAD/abnormal MRS, and CAD, respectively (P<0.01). After adjusting for CAD and cardiac risk factors, a phosphocreatine-adenosine triphosphate ratio decrease of 1% increased the risk of a cardiovascular event by 4% (P=0.02). The higher event rate in women with no CAD/abnormal MRS was primarily due to hospitalization for unstable angina, which is associated with repeat catheterization and higher healthcare costs. CONCLUSIONS: Among women without CAD, abnormal MRS consistent with myocardial ischemia predicted cardiovascular outcome, notably higher rates of anginal hospitalization, repeat catheterization, and greater treatment costs. Further evaluation into the underlying pathophysiology and possible treatment options for women with evidence of myocardial ischemia but without CAD is indicated.

Socioeconomic status variables predict cardiovascular disease risk factors and prospective mortality risk among women with chest pain. The WISE Study.

This study examined the relationship between socioeconomic status (SES), coronary artery disease (CAD) risk factors, and all-cause mortality in a cohort of women with chest pain. A total of 743 women (mean age = 59.6 years) with chest pain who were referred for coronary angiography completed a diagnostic protocol including CAD risk factor assessment, ischemic testing, psychosocial testing, and queries of SES. Patients were followed for about 2 years to track subsequent all-cause mortality. Results indicated that low SES was associated with CAD risk factors, including higher BMI and waist-hip ratios, cigarette smoking, lower reported activity levels, and a greater probability of hypertension. Low income also predicted all-cause mortality (RR = 2.7, 95% CI 1.4, 5.2), including after adjusting for proposed psychosocial and behavioral variables (RR = 5.9, 95% CI 1.2-29.7). Future research will require a thorough a priori focus on potential mechanisms to better understand SES effects on health.

The association of sex and payer status on management and subsequent survival in acute myocardial infarction.

BACKGROUND: Previous reports have generally shown lower utilization of hospital resources and lower survival in women than men with acute myocardial infarction. However, to our knowledge, no reports have described the influence of payer status on the treatment and outcome of women and men with acute myocardial infarction. METHODS: Baseline and clinical presenting characteristics, utilization of hospital resources, and subsequent clinical outcome were ascertained among 327 040 women and men enrolled in a national registry of myocardial infarction from June 1, 1994, to January 31, 1997. Separate Cox regression analyses were performed for Medicare, Medicaid, health maintenance organizations, and commercial payer groups to ascertain variables that were predictive of mortality in the study population. RESULTS: After adjustment for differences in age and other baseline and presenting characteristics, women were significantly more likely than men to die in the hospital (hazard ratio, 1.13; 95% confidence interval, 1.10-1.16), and this difference was greatest among women with health maintenance organization and commercial insurance (hazard ratios, 1.30 and 1.29, respectively), and least among women with Medicare (hazard ratio, 1.07). However, after adjustment for the additional effect on short-term survival of sex differences in the utilization of both pharmacologic treatments administered within the first 24 hours and invasive cardiac procedures, the mortality difference observed for women and men further diminished (hazard ratio, 1.08; 95% confidence interval, 1.05-1.10). CONCLUSION: In this large registry, we did not observe significant variations among payer classes in management and mortality among women and men after acute myocardial infarction.