Real-world clinical burden and economic assessment associated with hyperkalaemia in a large integrated healthcare system: a retrospective analysis

Background

Hyperkalaemia (HK) is a serious and potentially life-threatening condition. Both acute and chronic conditions may alter potassium homeostasis. Our aim is to describe HK incidence, clinical outcomes, and associated resource use within a large, integrated healthcare system.

Methods

Adult patients seen at Intermountain Healthcare facilities with a serum potassium (sK) result between January 1, 2003 and December 31, 2018 were retrospectively studied. Descriptive assessment of a population with detected HK, defined by any sK > 5.0 mmol/L and HK frequency and severity to associated resource use and characteristics of HK predictors were made. Multivariable Cox hazard regression was used to evaluate HK to outcomes.

Results

Of 1,208,815 patients included, 13% had HK. Compared to no-HK, HK patients were older (60 ± 18 vs 43 ± 18 years, P < 0.001), male (51% vs 41%, P < 0.001), and had greater disease burden (Charlson Comorbidity Index 3.5 ± 2.8 vs 1.7 ± 1.4, P < 0.001). At 3 years, more HK patients experienced major adverse cardiovascular events (MACEs) (19 vs 3%, P < 0.001), persisting post-adjustment (multivariable hazard ratio = 1.60, P < 0.001). They incurred higher costs for emergency department services ($552 ± 7,574 vs $207 ± 1,930, P < 0.001) and inpatient stays ($10,956 ± 93,026 vs $1,477 ± 21,423, P < 0.001). HyperK Risk Scores for the derivation and validation cohorts were: 44% low-risk, 45% moderate-risk, 11% high-risk. Strongest HK predictors were renal failure, dialysis, aldosterone blockers, diabetes, and smoking.

Conclusion

Within this large system, HK was associated with a large clinical burden, affecting over 1 in 10 patients; HK was also associated with increased 3-year MACE risk and higher medical costs. Although risk worsened with more severe or persistently recurring HK, even mild or intermittent HK episodes were associated with significantly greater adverse clinical outcomes and medical costs. The HyperK Score predicted patients who may benefit from closer management to reduce HK risk and associated costs. It should be remembered that our assumptions are valid only for detected HK and not HK per se.

Behavioral Nudges as Patient Decision Support for Medication Adherence: The ENCOURAGE Randomized Controlled Trial

BACKGROUND

Medication adherence is generally low and challenging to address because patient actions control healthcare delivery outside of medical environments. Behavioral nudging changes clinician behavior, but nudging patient decision-making requires further testing. This trial evaluated whether behavioral nudges can increase statin adherence, measured as the proportion of days covered (PDC).

METHODS

In a 12-month parallel-group, unblinded, randomized controlled trial, adult patients in Intermountain Healthcare cardiology clinics were enrolled. Inclusion required an indication for statins and membership in SelectHealth insurance. Subjects were randomized 1:1 to control or nudges. Nudge content, timing, frequency, and delivery route were personalized by CareCentra using machine learning of subject motivations and abilities from psychographic assessment, demographics, social determinants, and the Intermountain Mortality Risk Score. PDC calculation used SelectHealth claims data.

RESULTS

Among 182 subjects, age averaged 63.2±8.5 years, 25.8% were female, baseline LDL-C was 82.5±32.7 mg/dL, and 93.4% had coronary disease. Characteristics were balanced between nudge (n = 89) and control arms (n = 93). The statin PDC was greater at 12 months in the nudge group (PDC: 0.742±0.318) compared to controls (PDC: 0.639±0.358, P = 0.042). Adherent subjects (PDC ≥80%) were more concentrated in the nudge group (66.3% vs controls: 50.5%, P = 0.036) while a composite of death, myocardial infarction, stroke, and revascularization was non-significant (nudges: 6.7% vs control: 10.8%, P = 0.44).

CONCLUSIONS

Persuasive behavioral nudges driven by artificial intelligence resulted in a clinically important increase in statin adherence in general cardiology patients. This precision patient decision support utilized computerized nudge design and delivery with minimal on-going human input.

High Statin Adherence over 5 Years of Follow-up is Associated with Improved Cardiovascular Outcomes in Patients with Atherosclerotic Cardiovascular Disease: Results from the IMPRES Study

AIMS

Despite proven benefits of LDL-C lowering among those with atherosclerotic cardiovascular disease (ASCVD), statin adherence remains low. Very little real-world data exist on the effect of long-term statin adherence on cardiovascular outcomes.

METHODS AND RESULTS

A total of 7,339 patients ≥18 years first diagnosed with ASCVD with a statin prescription within 12-months of diagnosis who had 5-years of continuous Select Health insurance or died during years 2-5 while a member were studied. The proportion of days covered (PDC) was calculated using pharmacy claims for statin use by year, and patients were stratified into pre-defined categories: Fully-adherent (PDC≥80% for years 1-5 or until death, n = 353[4.8%]), Short-term-adherent (PDC≥80% for years 1-3, n = 330[4.5%]), Early-adherent-only (PDC≥80% for year 1, n = 890[12.1%]), Complex-adherent (PDC≥80% in any of years 2-5, but not year 1, n = 1,292[17.6%]), and Non-adherent (PDC<80% for years 1-5 or until death, n = 3,942[72.1%]). Patients were followed for major adverse clinical events (MACE=death, MI, and stroke). Patients averaged 56.4±9.6 years and 76.5% were male. During year 1, statin adherence was poor, with PDC<20% in 4,007 (54.6%) patients and PDC ≥80% in 1,573 (21.4%) patients, which dropped to 16.9% by year 5. Increased adherence was associated with significantly fewer MACE (11.6%, 17.9%, 21.9%, 21.1%, and 26.4% for those fully-adherent, short-term-adherent, early-adherent only, complex-adherent, and non-adherent, respectively, p-trend<0.0001). After adjustment, fully-adherent was associated with a significant decrease in MACE (HR = 0.51 [0.37, 0.71]).

CONCLUSION

Among ASCVD patients with at least 5-years of continuous pharmacy benefits, long-term adherence to statins was associated with decreased long-term MACE in a linear-fashion.

Frequency and clinical impact of hyperkalaemia within a large, modern, real-world heart failure population

AIMS

This analysis qualitatively describes the impact of hyperkalaemia (HK) and renin-angiotensin-aldosterone system inhibitor (RAASi) use on clinical outcomes in patients with heart failure (HF).

METHODS AND RESULTS

Patients were included if they were ≥18 years old; had a serum potassium result between 1 January 2003 and 3 December 2018; had ≥2 separate, non-urgent care or emergency department encounters; and had an HF diagnosis. Criteria were met by 52 253 patients; 48 333 had sufficient follow-up for analysis. Patients were stratified by the presence/absence of HK (serum potassium >5.0 mmol/L) (n = 31 619 and n = 20 634, respectively) and by baseline left ventricular ejection fraction (LVEF) ≤40% or >40%. Compared with patients without HK (no-HK), those with HK had significantly higher rates of baseline cardiovascular risk factors, prior diagnoses, and greater RAASi use in both baseline and follow-up periods. Assessed outcomes included RAASi use, rate of 3 year major adverse cardiovascular events (MACE), and individual component rates. Between baseline and follow-up analyses, the proportion of patients on RAASi decreased by 5% in patients with HK but increased by 20% in no-HK patients. Overall, MACE and death were consistently highest in the presence of HK without RAASi treatment (63% and 62%, respectively) and lowest in no-HK but on RAASi (25% and 21%, respectively). After complete multivariable adjustment, these trends were consistent regardless of baseline LVEF.

CONCLUSIONS

In this large, real-world HF population, HK was common and linked to baseline clinical risk factors, declining use of RAASi treatment, and an increase in future MACE, regardless of baseline LVEF. Both HK and reduced RAASi use were independent predictors of future MACE.

Absence of Coronary Artery Calcium During Positron Emission Tomography Stress Testing in Patients Without Known Coronary Artery Disease Identifies Individuals With Very Low Risk of Cardiac Events

Background:

Myocardial perfusion imaging, including positron emission tomography/computed tomography (PET/CT), is often used to assess for high-grade coronary artery disease (CAD) requiring revascularization. The use of coronary artery calcium (CAC) to predict risk of major adverse cardiovascular events in asymptomatic patients is accepted. However, little is known regarding the use of CAC in PET/CT patients without known CAD in identifying patients unlikely to need revascularization. Here, we determined whether the absence of CAC, using low-dose attenuation correction CT obtained during the PET/CT, identifies patients unlikely to undergo coronary revascularization within 90 days of a PET/CT.

Methods:

Patients, without a history of CAD and no elevation in troponin, referred for PET/CT at Intermountain Medical Center were studied (n=5528). The presence of CAC was visually assessed using low-dose attenuation correction CT. The association between CAC and 90-day high-grade CAD and revascularization were assessed. Longer-term (up to 4 years) major adverse cardiovascular events, including all-cause death, myocardial infarction, and late revascularization (>90 days), were examined.

Results:

There were 2510 (45.4%) patients in CAC-present group and 3018 (54.6%) patients in CAC-absent group. The CAC-absent group, compared with the CAC-present group, was less likely to undergo coronary angiography (3.4% versus 10.2%, P <0.0001), have high-grade CAD (0.5% versus 6.5%, P <0.0001), and receive revascularization (0.4% versus 5.8%, [adjusted odds ratio =0.09; 95% CI, 0.05–0.16]; P <0.0001). In patients with an ischemic burden >10%, the CAC-absent group was associated with reduced revascularization ( P <0.0001). Longer-term major adverse cardiovascular events were lower in the CAC-absent (2.4%) compared with the CAC-present (6.9%) group (adjusted hazard ratio, 0.45 [95% CI, 0.34–0.60]; P <0.0001).

Conclusions:

The absence of CAC on low-dose attenuation correction CT identifies PET/CT patients unlikely to have high-grade CAD or require revascularization within 90 days and unlikely to experience longer-term major adverse cardiovascular events. The prognostic value of CAC, beyond ischemic burden, suggests its potential as a first-step screening tool in intermediate-risk patients to identify those who do not need coronary revascularization.

Prediction of Long-Term Incidence of Chronic Cardiovascular and Cardiopulmonary Diseases in Primary Care Patients for Population Health Monitoring: The Intermountain Chronic Disease Model (ICHRON)

OBJECTIVE

To apply the practical parsimonious modeling method of the Intermountain Mortality Risk Score in a primary care environment to predict chronic disease (ChrD) onset.

PATIENTS AND METHODS

Primary care patients free of ChrD (women: n=98,711; men: n=45,543) were evaluated to develop (70% [n=95,882] of patients) and validate (the other 30% [n=48,372]) the sex-specific Intermountain Chronic Disease Risk Score (ICHRON) if seen initially between January 1, 2003, and December 31, 2005. The sex-specific ICHRON was composed of comprehensive metabolic profile and complete blood count components and age. The primary outcome was the first diagnosis of coronary artery disease, myocardial infarction, heart failure, atrial fibrillation, stroke, diabetes, renal failure, chronic obstructive pulmonary disease, peripheral vascular disease, or dementia within 3 years of baseline.

RESULTS

At 3 years, 9.0% of men (mean age, 44±16 years) and 6.6% of women (mean age, 42±16 years) received a diagnosis of ChrD. In the derivation population, C-statistics were 0.783 (95% CI, 0.774-0.791) for men and 0.774 (95% CI, 0.767-0.781) for women. In the validation population, C-statistics were 0.774 (95% CI, 0.762-0.786) for men and 0.762 (95% CI, 0.752-0.772) for women. Evaluation of 10-year outcomes for ICHRON and analysis of its association with each outcome individually at 3 years revealed similar predictive ability.

CONCLUSION

An augmented intelligence clinical decision tool for primary care, ICHRON, is developed using common laboratory parameters, which provides good discrimination of ChrD risk at 3 and 10 years.

Safety and Efficacy of Periprocedural Heparin Plus a Short-Term Infusion of Tirofiban Versus Bivalirudin Monotherapy in Patients Who Underwent Percutaneous Coronary Intervention (from the Intermountain Heart Institute STAIR Observational Registry)

Glycoprotein IIb/IIIa inhibitors, used as a standard intravenous bolus followed by a prolonged infusion for 12 to 18 hours, reduces ischemic complications during percutaneous coronary interventions (PCI) but often at a cost of increased bleeding. Today, when dual oral antiplatelet therapy is routine, heparin use plus short-term (bolus alone or with a <6 hours infusion) glycoprotein IIb/IIIa inhibitors, or bivalirudin monotherapy, have been proposed as potentially superior alternatives. This observational study evaluated the safety and efficacy of heparin plus short-term tirofiban versus bivalirudin monotherapy during PCI. Patients with successful PCI and no cardiogenic shock who were anticoagulated with either of the above regimens were followed for 30-day major bleeding and major adverse cardiovascular events (death, nonfatal myocardial infarction, and urgent target vessel revascularization) at 30 days, 1 year, and long term. A total of 727 patients receiving tirofiban (age = 63 ± 13 years, males = 76%, ACS presentation = 75%, radial access = 51%) and 459 patients receiving bivalirudin, (age = 65 ± 13 years, males = 71%, ACS presentation = 78%, radial access = 18%) were included. Thirty-day major bleeding was 0.7% and 4.1% for tirofiban and bivalirudin, respectively (adjusted odds ratio = 0.17 [0.06, 0.46], p = 0.001). During 30-day, 1-year, and long-term (1.7 ± 0.9 years) follow-up, major adverse cardiovascular events risk did not differ significantly between tirofiban and bivalirudin. However, long-term death was significantly lower in those receiving tirofiban (adjusted hazard ratio = 0.58 [0.34, 1.00], p = 0.05). In conclusion, in this observational study, PCI patients receiving heparin plus short-term tirofiban experienced significantly lower 30-day major bleeding, and improved long-term survival, than those receiving bivalirudin monotherapy.

Improving CHA2DS2-VASc stratification of non-fatal stroke and mortality risk using the Intermountain Mortality Risk Score among patients with atrial fibrillation

Background

Oral anticoagulation (OAC) therapy guidelines recommend using CHA₂DS₂-VASc to determine OAC need in atrial fibrillation (AF). A usable tool, CHA₂DS₂-VASc is challenged by its predictive ability. Applying components of the complete blood count and basic metabolic profile, the Intermountain Mortality Risk Score (IMRS) has been extensively validated. This study evaluated whether use of IMRS with CHA₂DS₂-VASc in patients with AF improves prediction.

Methods

Patients with AF undergoing cardiac catheterisation (N=10 077) were followed for non-fatal stroke and mortality (mean 5.8±4.1 years, maximum 19 years). CHA₂DS₂-VASc and IMRS were calculated at baseline. IMRS categories were defined based on previously defined criteria. Cox regression was adjusted for demographic, clinical and treatment variables not included in IMRS or CHA₂DS₂-VASc.

Results

In women (n=4122, mean age 71±12 years), the composite of non-fatal stroke/mortality was stratified (all p-trend <0.001) by CHA₂DS₂-VASc (1: 12.6%, 2: 22.8%, >2: 48.1%) and IMRS (low: 17.8%, moderate: 40.9%, high risk: 64.5%), as it was for men (n=5955, mean age 68±12 years) by CHA₂DS₂-VASc (<2: 15.7%, 2: 30.3%, >2: 51.8%) and IMRS (low: 19.0%, moderate: 42.0%, high risk: 65.9%). IMRS stratified stroke/mortality (all p-trend <0.001) in each CHA₂DS₂-VASc category.

Conclusions

Using IMRS jointly with CHA₂DS₂-VASc in patients with AF improved the prediction of stroke and mortality. For example, in patients at the OAC treatment threshold (CHA₂DS₂ -VASc = 2), IMRS provided ≈4-fold separation between low and high risk. IMRS provides an enhancing marker for risk in patients with AF that reflects the underlying systemic nature of this disease that may be considered in combination with the CHA₂DS₂-VASc score.

Extreme erythrocyte macrocytic and microcytic percentages are highly predictive of morbidity and mortality

BACKGROUND

The red cell distribution width (RDW) is associated with health outcomes. Whether non-RDW risk information is contained in RBC sizes is unknown. This study evaluated the association of the percentage of extreme macrocytic RBCs (%Macro, RBC volume > 120 fl) and microcytic RBCs (%Micro, RBC volume < 60 fl) and the RDW-size distribution (RDW-sd) with mortality and morbidity.

METHODS

Patients (females, n = 165,770; males, n = 100,210) at Intermountain Healthcare were studied if they had a hematology panel between May 2014 and September 2016. Adjusted sex-specific associations of %Macro/%Micro and RDW-sd with mortality and 33 morbidities were evaluated.

RESULTS

Among females with fourth-quartile values of %Macro quartile and %Micro (referred to throughout as 4/4), there was an average of 7.2 morbidities versus 2.9 in the lowest risk (LR1) categories, 1/1, 1/2, 2/1, and 2/2 (P < 0.001). Among males, those in the 4/4 category had 8.0 morbidities, while those in the LR1 had 3.4 (P < 0.001). Cox regressions found %Macro/%Micro (4/4 vs. LR1, females: hazard ratio [HR] = 1.97 [95% CI = 1.53, 2.54]; males: HR = 2.17 [CI = 1.72, 2.73]), RDW-sd (quartile 4 vs. 1, females: HR = 1.33 [CI = 1.04, 1.69]; males: HR = 1.41 [CI = 1.10, 1.80]), and RDW (quartile 4 vs. 1, females: HR = 1.59 [CI = 1.26, 2.00]; males: HR = 1.23 [CI = 0.99, 1.52]) independently predicted mortality. Limitations include that the observational design did not reveal causality and unknown confounders may be unmeasured.

CONCLUSIONS

Concomitantly elevated %Macro and %Micro predicted the highest mortality risk and the greatest number of morbidities, revealing predictive ability of RBC volume beyond what is measured clinically. Mechanistic investigations are needed to explain the biological basis of these observations.

FUNDING

This study was supported by internal Intermountain Heart Institute funds and in-kind support from Sysmex America Inc.

Temporal changes in statin prescription and intensity at discharge and impact on outcomes in patients with newly diagnosed atherosclerotic cardiovascular disease-Real-world experience within a large integrated health care system: The IMPRES study

BACKGROUND

Statins are indicated for secondary atherosclerotic cardiovascular disease (ASCVD) prevention; however, multiple surveys have found treatment gaps in clinical application.

OBJECTIVE

To determine trends over 15 years in the prevalence and impact of a statin prescription and dose intensity at discharge after a first ASCVD event.

METHODS

The Intermountain Enterprise Data Warehouse was searched to identify all adults with a first encounter for ASCVD between January 1, 1999 and December 31, 2013, including coronary artery disease, cerebrovascular disease, and peripheral arterial disease, who survived the index event and were followed for ≥3 years or until death. Major adverse cardiovascular events (MACE) were assessed overall and in 5-year increments.

RESULTS

A total of 62,070 patients met inclusion criteria. Mean age was 65.9 ± 13.7 years, and most of them were male (64.7%). Increases in any statin (59.3% to 72.6% to 80.8%) and high-intensity prescription (3.1% to 14.2% to 28.1%) occurred over consecutive 5-year intervals and were greatest in coronary artery disease patients. Statin therapy was associated with a reduced risk of 3-year MACE (multivariable hazard ratio = 0.75 [0.72, 0.78], P < .0001), with a significant linear trend across dose intensities.

CONCLUSION

In a real-world experience within a large, integrated health care system, significant reductions in MACE were found in association with both any and high-intensity statin prescriptions following an ASCVD event. Temporal trends indicated progressive improvement in guideline-recommended prescriptions. However, treatment gaps remain in receipt of both any statin and, especially, a high-intensity statin prescription, and these represent prime opportunities for further improvement in secondary ASCVD prevention.

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.

Clinically feasible stratification of 1-year to 3-year post-myocardial infarction risk

Objective

Post-myocardial infarction (MI) care is crucial to preventing recurrent major adverse cardiovascular events (MACE), but can be complicated to personalise. A tool is needed that effectively stratifies risk of cardiovascular (CV) events 1–3 years after MI but is also clinically usable.

Methods

Patients surviving ≥1 year after an index MI with ≥1 risk factor for recurrent MI (ie, age ≥65 years, prior MI, multivessel coronary disease, diabetes, glomerular filtration rate <60 mL/min/1.73 m²) were studied. Cox regression derived sex-specific Intermountain Major Adverse Cardiovascular Events (IMACE) risk scores for the composite of 1-year to 3-year MACE (CV death, MI or stroke). Derivation was performed in 70% of subjects (n=1342 women; 3047 men), with validation in the other 30% (n=576 women; 1290 men). Secondary validations were also performed.

Results

In women, predictors of CV events were glucose, creatinine, haemoglobin, platelet count, red cell distribution width (RDW), age and B-type natriuretic peptide (BNP); among men, they were potassium, glucose, blood urea nitrogen, haematocrit, white blood cell count, RDW, mean platelet volume, age and BNP. In the primary validation, in women, IMACE ranged from 0 to 11 (maximum possible: 12) and had HR=1.44 per +1 score (95% CI 1.29 to 1.61; P<0.001); men had IMACE range 0–14 (maximum: 16) and HR=1.29 per +1 score (95% CI 1.20 to 1.38; P<0.001). IMACE ≥5 in women (≥6 in men) showed strikingly higher MACE risk.

Conclusions

Sex-specific risk scores strongly stratified 1-year to 3-year post-MI MACE risk. IMACE is an inexpensive, dynamic, electronically delivered tool for evaluating and better managing post-MI patient care.

Early inpatient calculation of laboratory-based 30-day readmission risk scores empowers clinical risk modification during index hospitalization

Improving 30-day readmission continues to be problematic for most hospitals. This study reports the creation and validation of sex-specific inpatient (i) heart failure (HF) risk scores using electronic data from the beginning of inpatient care for effective and efficient prediction of 30-day readmission risk.

METHODS

HF patients hospitalized at Intermountain Healthcare from 2005 to 2012 (derivation: n=6079; validation: n=2663) and Baylor Scott & White Health (North Region) from 2005 to 2013 (validation: n=5162) were studied. Sex-specific iHF scores were derived to predict post-hospitalization 30-day readmission using common HF laboratory measures and age. Risk scores adding social, morbidity, and treatment factors were also evaluated.

RESULTS

The iHF model for females utilized potassium, bicarbonate, blood urea nitrogen, red blood cell count, white blood cell count, and mean corpuscular hemoglobin concentration; for males, components were B-type natriuretic peptide, sodium, creatinine, hematocrit, red cell distribution width, and mean platelet volume. Among females, odds ratios (OR) were OR=1.99 for iHF tertile 3 vs. 1 (95% confidence interval [CI]=1.28, 3.08) for Intermountain validation (P-trend across tertiles=0.002) and OR=1.29 (CI=1.01, 1.66) for Baylor patients (P-trend=0.049). Among males, iHF had OR=1.95 (CI=1.33, 2.85) for tertile 3 vs. 1 in Intermountain (P-trend <0.001) and OR=2.03 (CI=1.52, 2.71) in Baylor (P-trend < 0.001). Expanded models using 182-183 variables had predictive abilities similar to iHF.

CONCLUSIONS

Sex-specific laboratory-based electronic health record-delivered iHF risk scores effectively predicted 30-day readmission among HF patients. Efficient to calculate and deliver to clinicians, recent clinical implementation of iHF scores suggest they are useful and useable for more precise clinical HF treatment.

Impact of Testosterone Replacement Therapy on Myocardial Infarction, Stroke, and Death in Men With Low Testosterone Concentrations in an Integrated Health Care System

The aim of this study was to assess the effect of testosterone replacement therapy (TRT) on cardiovascular outcomes. Men (January 1, 1996, to December 31, 2011) with a low initial total testosterone concentration, a subsequent testosterone level, and >3 years of follow-up were studied. Levels were correlated with testosterone supplement use. The primary outcome was major adverse cardiovascular events (MACE), defined as a composite of death, nonfatal myocardial infarction, and stroke at 3 years. Multivariate adjusted hazard ratios (HRs) comparing groups of persistent low (<212 ng/dl, n = 801), normal (212 to 742 ng/dl, n = 2,241), and high (>742 ng/dl, n = 1,694) achieved testosterone were calculated by Cox hazard regression. A total of 4,736 men were studied. Three-year rates of MACE and death were 6.6% and 4.3%, respectively. Subjects supplemented to normal testosterone had reduced 3-year MACE (HR 0.74; 95% confidence interval [CI] 0.56 to 0.98, p = 0.04) compared to persistently low testosterone, driven primarily by death (HR 0.65, 95% CI 0.47 to 0.90). HRs for MI and stroke were 0.73 (95% CI 0.40 to 1.34), p = 0.32, and 1.11 (95% CI 0.54 to 2.28), p = 0.78, respectively. MACE was noninferior but not superior for high achieved testosterone with no benefit on MI and a trend to greater stroke risk. In conclusion, in a large general health care population, TRT to normal levels was associated with reduced MACE and death over 3 years but a stroke signal with high achieved levels suggests a conservative approach to TRT.

Automated identification and predictive tools to help identify high-risk heart failure patients: pilot evaluation

OBJECTIVE

Develop and evaluate an automated identification and predictive risk report for hospitalized heart failure (HF) patients.

METHODS

Dictated free-text reports from the previous 24 h were analyzed each day with natural language processing (NLP), to help improve the early identification of hospitalized patients with HF. A second application that uses an Intermountain Healthcare-developed predictive score to determine each HF patient's risk for 30-day hospital readmission and 30-day mortality was also developed. That information was included in an identification and predictive risk report, which was evaluated at a 354-bed hospital that treats high-risk HF patients.

RESULTS

The addition of NLP-identified HF patients increased the identification score's sensitivity from 82.6% to 95.3% and its specificity from 82.7% to 97.5%, and the model's positive predictive value is 97.45%. Daily multidisciplinary discharge planning meetings are now based on the information provided by the HF identification and predictive report, and clinician's review of potential HF admissions takes less time compared to the previously used manual methodology (10 vs 40 min). An evaluation of the use of the HF predictive report identified a significant reduction in 30-day mortality and a significant increase in patient discharges to home care instead of to a specialized nursing facility.

CONCLUSIONS

Using clinical decision support to help identify HF patients and automatically calculating their 30-day all-cause readmission and 30-day mortality risks, coupled with a multidisciplinary care process pathway, was found to be an effective process to improve HF patient identification, significantly reduce 30-day mortality, and significantly increase patient discharges to home care.

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.

Effect of screening for coronary artery disease using CT angiography on mortality and cardiac events in high-risk patients with diabetes: the FACTOR-64 randomized clinical trial

IMPORTANCE

Coronary artery disease (CAD) is a major cause of cardiovascular morbidity and mortality in patients with diabetes mellitus, yet CAD often is asymptomatic prior to myocardial infarction (MI) and coronary death.

OBJECTIVE

To assess whether routine screening for CAD by coronary computed tomography angiography (CCTA) in patients with type 1 or type 2 diabetes deemed to be at high cardiac risk followed by CCTA-directed therapy would reduce the risk of death and nonfatal coronary outcomes.

DESIGN, SETTING, AND PARTICIPANTS

The FACTOR-64 study was a randomized clinical trial in which 900 patients with type 1 or type 2 diabetes of at least 3 to 5 years' duration and without symptoms of CAD were recruited from 45 clinics and practices of a single health system (Intermountain Healthcare, Utah), enrolled at a single-site coordinating center, and randomly assigned to CAD screening with CCTA (n = 452) or to standard national guidelines-based optimal diabetes care (n = 448) (targets: glycated hemoglobin level <7.0%, low-density lipoprotein cholesterol level <100 mg/dL, systolic blood pressure <130 mm Hg). All CCTA imaging was performed at the coordinating center. Standard therapy or aggressive therapy (targets: glycated hemoglobin level <6.0%, low-density lipoprotein cholesterol level <70 mg/dL, high-density lipoprotein cholesterol level >50 mg/dL [women] or >40 mg/dL [men], triglycerides level <150 mg/dL, systolic blood pressure <120 mm Hg), or aggressive therapy with invasive coronary angiography, was recommended based on CCTA findings. Enrollment occurred between July 2007 and May 2013, and follow-up extended to August 2014.

MAIN OUTCOMES AND MEASURES

The primary outcome was a composite of all-cause mortality, nonfatal MI, or unstable angina requiring hospitalization; the secondary outcome was ischemic major adverse cardiovascular events (composite of CAD death, nonfatal MI, or unstable angina).

RESULTS

At a mean follow-up time of 4.0 (SD, 1.7) years, the primary outcome event rates were not significantly different between the CCTA and the control groups (6.2% [28 events] vs 7.6% [34 events]; hazard ratio, 0.80 [95% CI, 0.49-1.32]; P = .38). The incidence of the composite secondary end point of ischemic major adverse cardiovascular events also did not differ between groups (4.4% [20 events] vs 3.8% [17 events]; hazard ratio, 1.15 [95% CI, 0.60-2.19]; P = .68).

CONCLUSIONS AND RELEVANCE

Among asymptomatic patients with type 1 or type 2 diabetes, use of CCTA to screen for CAD did not reduce the composite rate of all-cause mortality, nonfatal MI, or unstable angina requiring hospitalization at 4 years. These findings do not support CCTA screening in this population.

TRIAL REGISTRATION

clinicaltrials.gov Identifier: NCT00488033.

Randomized cross-over trial of short-term water-only fasting: metabolic and cardiovascular consequences

BACKGROUND AND AIMS

Routine, periodic fasting is associated with a lower prevalence of coronary artery disease (CAD). Animal studies show that fasting may increase longevity and alter biological parameters related to longevity. We evaluated whether fasting initiates acute changes in biomarker expression in humans that may impact short- and long-term health.

METHODS AND RESULTS

Apparently-healthy volunteers (N = 30) without a recent history of fasting were enrolled in a randomized cross-over trial. A one-day water-only fast was the intervention and changes in biomarkers were the study endpoints. Bonferroni correction required p ≤ 0.00167 for significance (p < 0.05 was a trend that was only suggestively significant). The one-day fasting intervention acutely increased human growth hormone (p = 1.1 × 10⁻⁴), hemoglobin (p = 4.8 × 10⁻⁷), red blood cell count (p = 2.5 × 10⁻⁶), hematocrit (p = 3.0 × 10⁻⁶), total cholesterol (p = 5.8 × 10⁻⁵), and high-density lipoprotein cholesterol (p = 0.0015), and decreased triglycerides (p = 1.3 × 10⁻⁴), bicarbonate (p = 3.9 × 10⁻⁴), and weight (p = 1.0 × 10⁻⁷), compared to a day of usual eating. For those randomized to fast the first day (n = 16), most factors including human growth hormone and cholesterol returned to baseline after the full 48 h, with the exception of weight (p = 2.5 × 10⁻⁴) and (suggestively significant) triglycerides (p = 0.028).

CONCLUSION

Fasting induced acute changes in biomarkers of metabolic, cardiovascular, and general health. The long-term consequences of these short-term changes are unknown but repeated episodes of periodic short-term fasting should be evaluated as a preventive treatment with the potential to reduce metabolic disease risk. Clinical trial registration (ClinicalTrials.gov): NCT01059760 (Expression of Longevity Genes in Response to Extended Fasting [The Fasting and Expression of Longevity Genes during Food abstinence {FEELGOOD} Trial]).

Repeated measurement of the intermountain risk score enhances prognostication for mortality

Background

The Intermountain Risk Score (IMRS), composed of the complete blood count (CBC) and basic metabolic profile (BMP), predicts mortality and morbidity in medical and general populations. Whether longitudinal repeated measurement of IMRS is useful for prognostication is an important question for its clinical applicability.

Methods

Females (N = 5,698) and males (N = 5,437) with CBC and BMP panels measured 6 months to 2.0 years apart (mean 1.0 year) had baseline and follow-up IMRS computed. Survival analysis during 4.0±2.5 years (maximum 10 years) evaluated mortality (females: n = 1,255 deaths; males: n = 1,164 deaths) and incident major events (myocardial infarction, heart failure [HF], and stroke).

Results

Both baseline and follow-up IMRS (categorized as high-risk vs. low-risk) were independently associated with mortality (all p<0.001) in bivariable models. For females, follow-up IMRS had hazard ratio (HR) = 5.23 (95% confidence interval [CI] = 4.11, 6.64) and baseline IMRS had HR = 3.66 (CI = 2.94, 4.55). Among males, follow-up IMRS had HR = 4.28 (CI = 3.51, 5.22) and baseline IMRS had HR = 2.32 (CI = 1.91, 2.82). IMRS components such as RDW, measured at both time points, also predicted mortality. Baseline and follow-up IMRS strongly predicted incident HF in both genders.

Conclusions

Repeated measurement of IMRS at baseline and at about one year of follow-up were independently prognostic for mortality and incident HF among initially hospitalized patients. RDW and other CBC and BMP values were also predictive of outcomes. Further research should evaluate the utility of IMRS as a tool for clinical risk adjustment.

The intermountain risk score predicts incremental age-specific long-term survival and life expectancy

The Intermountain Risk Score (IMRS) encapsulates the mortality risk information from all components of the complete blood count (CBC) and basic metabolic profile (BMP), along with age. To individualize the IMRS more clearly, this study evaluated whether IMRS weightings for 1-year mortality predict age-specific survival over more than a decade of follow-up. Sex-specific 1-year IMRS values were calculated for general medical patients with CBC and BMP laboratory tests drawn during 1999-2005. The population was divided randomly 60% (N = 71,921, examination sample) and 40% (N = 47,458, validation sample). Age-specific risk thresholds were established, and both survival and life expectancy were compared across low-, moderate-, and high-risk IMRS categories. During 7.3 ± 1.8 years of follow-up (range, 4.5-11.1 years), the average IMRS of decedents was higher than censored in all age/sex strata (all P < 0.001). For examination and validation samples, every age stratum had incrementally lower survival for higher risk IMRS, with hazard ratios of 2.5-8.5 (P < 0.001). Life expectancies were also significantly shorter for higher risk IMRS (all P < 0.001): For example, among 50-59 year-olds, life expectancy was 7.5, 6.8, and 5.9 years for women with low-, moderate-, and high-risk IMRS (with mortality in 5.7%, 16.3%, and 37.0% of patients, respectively). In Men, life expectancy was 7.3, 6.8, and 5.4 for low-, moderate-, and high-risk IMRS (with patients having 7.3%, 19.5%, and 40.0% mortality), respectively. IMRS significantly stratified survival and life expectancy within age-defined subgroups during more than a decade of follow-up. IMRS may be used to stratify age-specific risk of mortality in research, clinical/preventive, and quality improvement applications. A web calculator is located at http://intermountainhealthcare.org/IMRS.

Parathyroid hormone, vitamin D, renal dysfunction, and cardiovascular disease: dependent or independent risk factors?

BACKGROUND

Vitamin D (Vit D) deficiency has been associated with prevalent and incident cardiovascular (CV) disease, suggesting a role for bioregulators of bone and mineral metabolism in CV health. Vitamin D deficiency leads to secondary hyperparathyroidism, and both primary and secondary hyperparathyroidism are associated with CV pathology. Parathyroid hormone (PTH) is an important regulator of calcium homeostasis, and its impact on CV disease risk is of interest. We tested whether elevated PTH is associated with CV disease and whether risk associations depend on Vit D status and renal function.

METHODS

Patients in the Intermountain Healthcare system with concurrent PTH and Vit D as 25-hydroxy-vitamin D (25[OH]D) levels were studied (N = 9,369, age 63 ± 16 years, 36% male). Parathyroid hormone levels were defined as low (<15 pg/mL), normal (15-75 pg/mL), or elevated (>75 pg/mL). Prevalence and incidence of hypertension, diabetes, hyperlipidemia, coronary artery disease/myocardial infarction, heart failure, stroke, and peripheral vascular disease were determined by the International Classification of Diseases, Ninth Revision codes documented in electronic medical records at baseline and, for incident events, during an average of 2.0 ± 1.5 years (maximum 7.5 years) of follow-up.

RESULTS

Parathyroid hormone elevation at baseline was noted in 26.1% of the study population. Highly significant differential CV prevalence/incidence rates for most CV risk factors, disease diagnoses, and mortality were noted for PTH >75 pg/mL (by 1.25- to 3-fold). Parathyroid hormone correlated only weakly (r = -0.15) with 25(OH)D and moderately with glomerular filtration rate (r = -0.36). 25(OH)D, standard risk factors, and renal dysfunction variably attenuated PTH risk associations, but risk persisted after full multivariable adjustment.

CONCLUSIONS

Elevated PTH is associated with a greater prevalence and incidence of CV risk factors and predicts a greater likelihood of prevalent and incident disease, including mortality. Risk persists when adjusted for 25(OH)D, renal function, and standard risk factors. Parathyroid hormone represents an important new CV risk factor that adds complementary and independent predictive value for CV disease and mortality.

Genome-wide significance and replication of the chromosome 12p11.22 locus near the PTHLH gene for peripartum cardiomyopathy

BACKGROUND

Peripartum (PP) cardiomyopathy (CM) is a rare condition of unknown etiology that occurs in late pregnancy or early postpartum. Initial evidence suggests that genetic factors may influence PPCM. This study evaluated and replicated genome-wide association of single nucleotide polymorphisms with PPCM.

METHODS AND RESULTS

Genome-wide single nucleotide polymorphisms in women with verified PPCM diagnosis (n=41) were compared separately with local control subjects (n=49 postmenopausal age-discordant women with parity ≥1 and no heart failure) and iControls (n=654 women ages 30 to 84 years with unknown phenotypes). A replication study of independent population samples used new cases (PPCM2, n=30) compared with new age-discordant control subjects (local2, n=124) and with younger control subjects (n=89) and obstetric control subjects (n=90). A third case set of pregnancy-associated CM cases not meeting strict PPCM definitions (n=29) was also studied. In the genome-wide association study, 1 single nucleotide polymorphism (rs258415) met genome-wide significance for PPCM versus local control subjects (P=2.06×10(-8); odds ratio [OR], 5.96). This was verified versus iControls (P=7.92×10(-19); OR, 8.52). In the replication study for PPCM2 cases, rs258415 (ORs are per C allele) replicated at P=0.009 versus local2 control subjects (OR, 2.26). This replication was verified for PPCM2 versus younger control subjects (P=0.029; OR, 2.15) and versus obstetric control subjects (P=0.013; OR, 2.44). In pregnancy-associated cardiomyopathy cases, rs258415 had a similar effect versus local2 control subjects (P=0.06; OR, 1.79), younger control subjects (P=0.14; OR, 1.65), and obstetric control subjects (P=0.038; OR, 1.99).

CONCLUSIONS

Genome-wide association with PPCM was discovered and replicated for rs258415 at chromosome 12p11.22 near PTHLH. This study indicates a role of genetic factors in PPCM and provides a new locus for further pathophysiological and clinical investigation.

Relation of vitamin D deficiency to cardiovascular risk factors, disease status, and incident events in a general healthcare population

Vitamin D recently has been proposed to play an important role in a broad range of organ functions, including cardiovascular (CV) health; however, the CV evidence-base is limited. We prospectively analyzed a large electronic medical records database to determine the prevalence of vitamin D deficiency and the relation of vitamin D levels to prevalent and incident CV risk factors and diseases, including mortality. The database contained 41,504 patient records with at least one measured vitamin D level. The prevalence of vitamin D deficiency (≤30 ng/ml) was 63.6%, with only minor differences by gender or age. Vitamin D deficiency was associated with highly significant (p <0.0001) increases in the prevalence of diabetes, hypertension, hyperlipidemia, and peripheral vascular disease. Also, those without risk factors but with severe deficiency had an increased likelihood of developing diabetes, hypertension, and hyperlipidemia. The vitamin D levels were also highly associated with coronary artery disease, myocardial infarction, heart failure, and stroke (all p <0.0001), as well as with incident death, heart failure, coronary artery disease/myocardial infarction (all p <0.0001), stroke (p = 0.003), and their composite (p <0.0001). In conclusion, we have confirmed a high prevalence of vitamin D deficiency in the general healthcare population and an association between vitamin D levels and prevalent and incident CV risk factors and outcomes. These observations lend strong support to the hypothesis that vitamin D might play a primary role in CV risk factors and disease. Given the ease of vitamin D measurement and replacement, prospective studies of vitamin D supplementation to prevent and treat CV disease are urgently needed.

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.

Association of vitamin D levels with incident depression among a general cardiovascular population

BACKGROUND

Depression is associated with cardiovascular (CV) disease, and it has been hypothesized that vitamin (vit)D deficiency may be associated with depression and a contributing factor to excess CV events. Therefore, we evaluated whether there is an association between vitD and incident depression among a CV population.

METHODS

Patients (N = 7,358) > or =50 years of age, with a CV diagnosis (coronary artery disease, myocardial infarction, congestive heart failure, cerebrovascular accident, transient ischemic accident, atrial fibrillation, or peripheral vascular disease), no prior depression diagnosis, and a measured vitD level were studied. Vitamin D (ng/mL) was stratified into 4 categories: >50 (optimal [O] n = 367), 31 to 50 (normal [N] n = 2,264), 16 to 30 (low [L] n = 3,402), and > or =15 (very low [VL] n = 1,325). Depression was defined by International Classification of Diseases, Ninth Edition, codes: 296.2 to 296.36, 311. VitD categories were evaluated by Cox hazard regression with adjustment by standard CV risk factors.

RESULTS

Age averaged 73.1 +/- 10.2 years, and 58.8% were female. When compared to O, VL, L, and N were associated with depression (adjusted: VL, hazard ratio [HR] 2.70 [1.35-5.40], P = .005; L, HR 2.15 [1.10-4.21], P = .03; N, HR 1.95 [0.99-3.87], P = .06). This association remained even after adjustment by parathyroid hormone levels. Parathyroid hormone was significantly associated with depression, however, became nonsignificant after adjustment by vitD. Winter (December-February) enhanced this association. Significant associations remained when stratifications were made by age (<65, > or =65), sex, and diabetes, although the associations among those age > or =65 and male sex were enhanced.

CONCLUSION

Among a CV population > or =50 years with no history of depression, vitD levels were shown to be associated with incident depression after vitD draw. This study strengthens the hypothesis of the association between vitD and depression.

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.

Superior predictive ability for death of a basic metabolic profile risk score

BACKGROUND

The basic metabolic profile (BMP) is a common blood test containing information about standard blood electrolytes and metabolites. Although individual variables are checked for cardiovascular health and risk, combining them into a total BMP-derived score, as to maximize BMP predictive ability, has not been previously attempted.

METHODS

Patients (N = 279,337) that received a BMP and had long-term follow-up for death were studied. Risk models were created in a training group (60% of study population, n = 167,635), validated in a test group (40% of study population, n = 111,702), and confirmed in the NHANES III (Third National Health and Nutrition Examination Survey) participants (N = 17,752). The BMP models were developed for 30-day, 1-year, and 5-year death using logistic regression with adjustment for age and sex. The BMP parameters were categorized as low, normal, or high based on the standard range of normal. Glucose was categorized as normal, intermediate, and high. Creatinine >or=2 mg/dL was further categorized as very high.

RESULTS

Average age was 53.2 +/- 20.1 years, and 44.3% were male. The areas under the curve for the training and test groups for 30-day, 1-year, and 5-year death were 0.887 and 0.882, 0.850 and 0.848, and 0.858 and 0.847, respectively. The predictive ability of these risk scores was further confirmed in the NHANES III population and independent of the Framingham Risk Score.

CONCLUSION

In large, prospectively followed populations, a highly significant predictive ability for death was found for a BMP risk model. We propose a total BMP score as an optimization of this routine baseline test to provide an important new addition to risk prediction.

Hyperglycemia predicts mortality after CABG: postoperative hyperglycemia predicts dramatic increases in mortality after coronary artery bypass graft surgery

OBJECTIVE

Risk of morbidity and mortality after coronary artery bypass graft surgery (CABG) is higher in patients with clinical diabetes mellitus (DM). We evaluated whether outcomes are affected by postoperative hyperglycemia in CABG patients independent of preoperative DM diagnosis.

RESEARCH DESIGN AND METHODS

A total of 2297 consecutive CABG patients were studied. The first glucose value after surgery completion (mean 15 min) was tested as a predictor of outcome. Primary outcome variables were prolonged ventilation (>24 h), deep sternal wound infection, renal failure, permanent stroke, any reoperation, length of stay (>14 days) and mortality. All outcomes except for prolonged ventilation and length of stay were tracked out to 30 days postoperatively. Patients were stratified by glycemic control: Low (glucose <80), normal (referent, glucose 80-110), high (glucose 111-200) and very high (glucose >200 mg/dl). Multivariable logistic regression was used to determine the independent predictive value of glycemic groups, adjusted for outcome specific risk scores from the Society of Thoracic Surgeons model.

RESULTS

Patient distribution among groups low through very high were 44 (1.9%), 476 (20.7%), 1425 (62.0%) and 352 (15.3%). Greater complication rates were noted in the very high group when compared with the referent group: prolonged ventilation (adjusted odds ratio (OR)=2.66, P<.001), length of stay >14 days (adjusted OR=2.06, P=.004) and mortality (adjusted OR=7.71, P<.001).

CONCLUSION

Patients with blood glucose values >200 mg/dl immediately after CABG had an increased risk of complications, including mortality, independent of a clinical diagnosis of DM. This study documents the high risk associated with early postoperative hyperglycemia in this group, suggesting the need for prospective trials of glycemic control.

Usefulness of routine periodic fasting to lower risk of coronary artery disease in patients undergoing coronary angiography

Coronary artery disease (CAD) is common and multifactorial. Members of the Church of Jesus Christ of Latter-day Saints (LDS, or Mormons) in Utah may have lower cardiac mortality than other Utahns and the US population. Although the LDS proscription of smoking likely contributes to lower cardiac risk, it is unknown whether other shared behaviors also contribute. This study evaluated potential CAD-associated effects of fasting. Patients (n(1) = 4,629) enrolled in the Intermountain Heart Collaborative Study registry (1994 to 2002) were evaluated for the association of religious preference with CAD diagnosis (> or = 70% coronary stenosis using angiography) or no CAD (normal coronaries, <10% stenosis). Consequently, another set of patients (n(2) = 448) were surveyed (2004 to 2006) for the association of behavioral factors with CAD, with routine fasting (i.e., abstinence from food and drink) as the primary variable. Secondary survey measures included proscription of alcohol, tea, and coffee; social support; and religious worship patterns. In population 1 (initial), 61% of LDS and 66% of all others had CAD (adjusted [including for smoking] odds ratio [OR] 0.81, p = 0.009). In population 2 (survey), fasting was associated with lower risk of CAD (64% vs 76% CAD; OR 0.55, 95% confidence interval 0.35 to 0.87, p = 0.010), and this remained after adjustment for traditional risk factors (OR 0.46, 95% confidence interval 0.27 to 0.81, p = 0.007). Fasting was also associated with lower diabetes prevalence (p = 0.048). In regression models entering other secondary behavioral measures, fasting remained significant with a similar effect size. In conclusion, not only proscription of tobacco, but also routine periodic fasting was associated with lower risk of CAD.

Surgical Revascularization Is Associated With Improved Long-Term Outcomes Compared With Percutaneous Stenting in Most Subgroups of Patients With Multivessel Coronary Artery Disease: Results From the Intermountain Heart Registry

BACKGROUND

Coronary artery bypass surgery (CABG) and percutaneous coronary intervention with stenting (PCI-S) are both safe and effective approaches for revascularization in patients with multivessel coronary artery disease. However, conflicting information exists when comparing the efficacy of the two methods. In this study, we examined the outcomes of major adverse cardiovascular events and death for subgroups of typical "real-world" patients undergoing coronary revascularization in the modern era.

METHODS AND RESULTS

Patients were included if they were revascularized by CABG or PCI-S, had > or = 5 years of follow-up, and had > or = 2-vessel disease. Patients were followed for an average of 7.0+/-3.2 years for incidence of death and major adverse cardiovascular events (death, myocardial infarction, or repeat revascularization). Multivariate regression models were used to correct for standard cardiac risk factors including age, sex, hyperlipidemia, diabetes mellitus, family history of coronary artery disease, smoking, hypertension, heart failure, and renal failure. Subgroup analyses were also performed, stratified by age, sex, diabetes, ejection fraction, and history of PCI-S, CABG, or myocardial infarction. A total of 6369 patients (CABG 4581; PCI-S 1788) were included. Age averaged 66+/-10.9 years, 76% were male, and 26% were diabetic. Multivariate risk favored CABG over PCI-S for both death (hazard ratio 0.85; P=0.001) and major adverse cardiovascular events (hazard ratio 0.51; P<0.0001). A similar advantage with CABG was also found in most substrata, including diabetes.

CONCLUSIONS

In this large observational study of patients undergoing revascularization for multivessel coronary artery disease, a long-term benefit was found, in relationship to both death and major adverse cardiovascular events, for CABG over PCI-S regardless of diabetic status or other stratifications.

Genotypes of the cytochrome p450 isoform, CYP2C9, and the vitamin K epoxide reductase complex subunit 1 conjointly determine stable warfarin dose: a prospective study

BACKGROUND

Warfarin has a narrow therapeutic range and wide inter-individual dosing requirements that may be related to functional variants of genes affecting warfarin metabolism (i.e., CYP2C9) and activity (i.e., vitamin K epoxide reductase complex subunit 1-VKORC1). We hypothesized that variants in these two genes explain a substantial proportion of variability in stable warfarin dose and could be used as a basis for improved dosing algorithms.

METHODS

Consecutive consenting outpatients (n = 213) with stable INR (2-3) for >1 month were enrolled. Buccal DNA was extracted using a Qiagen mini-column and CYP2C9*2 and VKORC1 genotyping performed by the Taqman 3' nuclease assay. Sequencing for CYP2C9*3, genotyping was done using Big Dye v3.1 terminator chemistry Dose by genotype was assessed by linear regression.

RESULTS

Weekly warfarin dose averaged 30.8 +/- 13.9 mg/week; average INR was 2.42 +/- 0.72. CYP2C9*2/*3 genotype distribution was: CC/AA (wild-type [WT]) = 71.4%, CT/AA = 18.3%, CC/AC = 9.4%, and CT/AC = 1%; VKORC1 genotypes were CC (WT) = 36.6%, CT = 50.7%, and TT = 12.7%. Warfarin doses (mg/week) varied by genotype: for CYP2C9, 33.3 mg/week for WT (CC/AA), 27.2 mg/week for CT/AA (P = 0.04 vs. WT), 23.0 mg/week for CC/AC (P = 0.003), and 6.0 mg/week for CT/AC (P < 0.001), representing dose reductions of 18-31% for single and 82% for double variant carriers; for VKORC1: 38.4 mg/week for WT (CC), 28.6 mg/week for CT (P < 0.001 vs. WT), 20.95 mg/week for TT (P < 0.001). In multiple linear regression, genotype was the dominant predictor of warfarin dose (P = 2.4 x 10(-15)); weak predictors were age, weight, and sex. Genotype-based modeling explained 33% of dose-variance, compared with 12% for clinical variables alone.

CONCLUSION

In this large prospective study of warfarin genetic dose-determinants, carriage of a single or double CYP2C9 variant, reduced warfarin dose 18-72%, and of a VKORC1 variant by 65%. Genotype-based modeling explained almost one-half of dose-variance. A quantitative dosing algorithm incorporating genotypes for 2C9 and VKORC1 could substantially improve initial warfarin dose-selection and reduce related complications.

Early Postoperative Use of Unfractionated Heparin or Enoxaparin is Associated with Increased Surgical Re-Exploration for Bleeding

BACKGROUND

A variety of indications (eg, prosthetic heart valves, atrial fibrillation, etc.) exist for the use of unfractionated heparin (UFH) and enoxaparin (ENOX) in the early postoperative period following open-heart surgery. However, the overall postoperative risk for hemorrhage from the use of UFH and ENOX are not known.

METHODS

From 1998 to 2001, 2,977 consecutive open-heart or valve surgery patients were retrospectively evaluated. Postoperatively, 2,037 received no UFH or ENOX, 579 received intravenous UFH, and 361 received ENOX. Baseline characteristics were collected, patients who required surgical re-exploration for postoperative bleeding and time between surgery and re-exploration were followed-up.

RESULTS

Average patient ages were 64 +/- 13, 65 +/- 12, and 68 +/- 10 years receiving none, UFH (p < 0.01 vs none), and ENOX (p < 0.01 vs none; p < 0.01 vs UFH), respectively. Rates of surgical re-exploration were 2.7% for none, 7.8% for UFH, and 8.9% for ENOX (vs none, adjusted hazard ratio = 2.8; p < 0.001 for UFH; hazard ratio = 3.3; p < 0.001 for ENOX). Males were also at higher risk for re-exploration (hazard ratio = 1.4; p = 0.07). For those requiring re-exploration, the interval between surgery and first re-exploration was prolonged (> 4 days) among those receiving ENOX (37.5%, odds ratio = 36.7; p = 0.001) and UFH (20.0%, odds ratio = 14.7; p = 0.01) compared with none (1.8%). Prolonged times with ENOX had a greater proportion of prolonged times than UFH (odds ratio = 2.5; p = 0.09).

CONCLUSIONS

Early postoperative use of ENOX and UFH is associated with a significant increase in re-exploration for postoperative bleeding, often at a significantly delayed time period after the initial surgery. This delay was especially common with ENOX suggesting the need for prospective studies.

Do statins increase the risk of idiopathic polyneuropathy?

A recent European case-control study suggested that statins increase the risk for polyneuropathy, a rare but serious neurologic condition. This risk was assessed in 272 patients with idiopathic polyneuropathy and 1,360 matched controls in the Intermountain Health Care electronic database. It was found that statin use before diagnosis was not significantly greater in patients than controls (odds ratio 1.30, 95% confidence interval 0.3 to 2.1, p = 0.27), nor were doses different between patients and controls.

Effect of beta-blocker therapy on mortality rates and future myocardial infarction rates in patients with coronary artery disease but no history of myocardial infarction or congestive heart failure

Beta-blocker therapy has been shown to benefit patients who have coronary artery disease and present with acute myocardial infarction (AMI) and/or congestive heart failure (HF). However, whether beta-blocker therapy provides a similar benefit in patients who have coronary artery disease but not AMI or HF is unknown. A population of 4,304 patients who did not have HF but did have angiographically confirmed coronary artery disease (>/=1 stenosis of >/=70%) without AMI at hospital presentation was evaluated. Baseline demographics, cardiac risk factors, clinical presentation, therapeutic procedures, and discharge medications were recorded. Patients were followed for a mean of 3.0 +/- 1.9 years (range 1 month to 6.9 years) for outcomes of all-cause death or AMI. Patients' average age was 65 +/- 11 years and 77% were men. Overall, 10% died and 5% had a nonfatal AMI. Discharge beta-blocker prescription was associated with an increased event-free AMI survival rate for all-cause death (no beta blocker 88.3%, beta blocker 94.5%, p <0.001) and death/AMI (no beta blocker 83.4%, beta blocker 89.2%, p <0.001) but not non-fatal AMI (no beta blocker 93.6%, beta blocker 94.1%, p = 0.60). After adjustment for 16 covariates, including statin prescription, angiotensin-converting enzyme inhibitor prescription, and type of baseline therapy, the effect of beta blockers on the combination end point of death/AMI was eliminated. However, the effect of beta blockers on death remained (hazard ratio 0.66, 95% confidence interval 0.47 to 0.93, p = 0.02). Thus, beta blockers are clearly indicated for most patients who have HF or AMI, and our results suggest that patients who have coronary artery disease without these conditions have approximately the same protective benefit against death. No effect was observed on longitudinal incidence of AMI or the combination of death/nonfatal MI.

Frequency of elevation of C-reactive protein in atrial fibrillation

Inflammation has been implicated in the pathogenesis of cardiovascular diseases. C-reactive protein (CRP), a marker of systemic inflammation, predicts the risk of coronary events and stroke. Atrial fibrillation (AF) is associated with atrial structural changes that may have an inflammatory basis. We tested the hypothesis that CRP is a risk factor for AF. Subjects were those included in the database registry of the Intermountain Heart Collaborative Study from 1994 to 2001. Patients who had >or=1 electrocardiogram that demonstrated AF formed the disease group (n = 347), and those who had neither electrocardiographic nor clinical evidence for AF comprised the control group (n = 2,449). Logistic regression assessed the quartile (Q) of CRP and 13 other clinical and angiographic predictors of AF. Average age was 63 +/- 12 years, 33% were women, and 61% had advanced coronary artery disease. Patients who had AF were older (by 7 years) and more frequently had a history of heart failure than did controls (41% vs 9%). CRP was higher in patients who had AF than in controls (p <0.001). Q-CRP was a univariable predictor of AF (odds ratio 1.39/Q, 95% confidence interval 1.25 to 1.55, p <0.001). Adjusting for age and heart failure decreased the predictive value of Q-CRP to 1.20/Q (95% confidence 1.07 to 1.34, p = 0.002), whereas further adjustment for 11 other variables had little additional effect (odds ratio 1.19/Q, 95% confidence interval 1.06 to 1.33, p = 0.003). Thus, high levels of CRP independently predicted an increased risk of AF among a large, prospectively studied patient cohort that was assessed angiographically. Increased CRP is a new risk marker for AF propensity, and testing therapies that target inflammation should be considered.

Improvements in 1-year cardiovascular clinical outcomes associated with a hospital-based discharge medication program

BACKGROUND

Despite recent advances in the treatment and prevention of cardiovascular disease, a treatment gap for secondary prevention medications still exists.

OBJECTIVE

To develop and implement a program ensuring appropriate prescription of aspirin, statins, beta-blockers, angiotensin-converting enzyme inhibitors, and warfarin at hospital discharge.

DESIGN

A nonrandomized before-after study comparing patients hospitalized before (1996-1998) and after (1999-2002) implementation of a discharge medication program (DMP). Patients were followed for up to 1 year.

SETTING

The 10 largest hospitals in the Utah-based Intermountain Health Care system.

PATIENTS

In the pre-DMP and DMP time periods, 26,000 and 31,465 patients, respectively, were admitted to cardiovascular services (n = 57,465).

MEASUREMENTS

Prescription of indicated medications at hospital discharge; postdischarge death or readmission.

RESULTS

By 1 year, the rate of prescription of each medication increased significantly to more than 90% (P < 0.001); this rate was sustained. At 1 year, unadjusted absolute event rates for readmission and death, respectively, were 210 per 1000 person-years and 96 per 1000 person-years before DMP implementation and 191 per 1000 person-years and 70 per 1000 person-years afterward. Relative risk for death and readmission at 30 days decreased after DMP implementation; hazard ratios (HRs) for death and readmission were 0.81 (95% CI, 0.73 to 0.89) and 0.92 (CI, 0.87 to 0.99) (P < 0.001 and P = 0.017, respectively). At 1 year, risk for death continued to decrease (hazard ratio, 0.79 [CI, 0.75 to 0.84]; P < 0.001) while risk for readmission stabilized (hazard ratio, 0.94 [CI, 0.90 to 0.98]; P = 0.002), probably because survivors had more opportunities to be readmitted.

LIMITATIONS

The study design was observational and nonrandomized, and the authors could not control for potential confounders or determine the extent to which secular trends accounted for the observed improvements.

CONCLUSIONS

A relatively simple quality improvement program aimed at enhancing the prescription of appropriate discharge medications among cardiovascular patients is feasible and can be sustained within an integrated multihospital system. Such a program may be associated with improvements in cardiovascular readmission rates and mortality.

Less affluent area of residence and lesser-insured status predict an increased risk of death or myocardial infarction after angiographic diagnosis of coronary disease

PURPOSE

Low socioeconomic status (SES) predicts coronary artery disease (CAD) onset, but its value among patients with CAD is uncertain. Geographic measures (e.g., residential neighborhood) may predict risk, but this requires further evaluation.

METHODS

A cohort of 3410 patients with significant, angiographically-defined CAD (> or =1 lesion of > or =70% stenosis) joined a registry during the period between 1993 and 2000 and was followed for 6.7 years (median 3.7 years). A geographic SES measure-residential economic status (RES)-and insurance type were examined for association with mortality or myocardial infarction (MI).

RESULTS

In Cox regression adjusting for 17 covariates, lower RES quartile was associated with increased death/MI (p-trend<0.001), death (p-trend=0.001), and MI (p-trend=0.07). First RES quartile (vs. fourth) predicted death/MI (hazard ratio [HR]=1.32, 95% confidence interval [CI]=1.07-1.62, p=0.01) and death (HR=1.46, CI=1.12-1.91, p=0.006), but not MI (HR=1.18, p=0.31). Compared with private insurance, self-pay (HR=1.88, p=0.053), charity care (HR=1.71, p<0.001), and Medicaid (HR=1.43, p=0.24), but not Medicare (HR=0.95, p=0.68), were associated with death/MI.

CONCLUSIONS

Both geographic (RES) and economic (insurance) measures of SES independently predicted risk of death/MI in a large population with angiographically-defined CAD. This suggests that SES remains a significant predictor of health outcomes after CAD has developed, and that geographic measures of SES deserve further evaluation.