In the News

Death risk after CABG, lower death rates after acute MI, and more.


Simplified score predicts death risk after CABG

A recently developed simplified score accurately predicts the risk of long-term mortality after coronary artery bypass grafting (CABG) surgery.

Researchers used the New York State Cardiac Surgery Reporting System to identify 8,597 patients from 34 hospitals who had undergone isolated CABG surgery between July and December 2000. They followed patients' vital statuses through 2007 using the National Death Index and used a Cox proportional hazards model to predict death after CABG using preprocedural risk factors. These factors included demographics, body surface area, body mass index (BMI), left main coronary disease, number of diseased coronary arteries, ejection fraction, history of myocardial infarction (MI), and several others. For patients who survived the first 30 days after CABG, a derivation model was used to predict survival at one, three, five and seven years after surgery.

A total of 2,156 deaths occurred in the study period. One-, three-, five- and seven-year mortality rates were 6.2%, 11.2%, 17.6% and 24.2%, respectively. Independent predictors of death after CABG surgery via Cox proportional hazards model were older age, BMI <25 kg/m2 or ≥40 kg/m2, lower ejection fractions, unstable hemodynamic state/shock, left main coronary disease, cerebrovascular disease, peripheral arterial disease, congestive heart failure, malignant ventricular arrhythmia, chronic obstructive pulmonary disease, diabetes, renal failure and history of open heart surgery. At seven years' follow-up, the C-statistic was 0.782. Results were published in the May 22 Circulation.

The predictors for long-term mortality identified in this study are generally consistent with other studies, the authors noted. Study limitations include that the data are from patients who underwent CABG a decade ago, and quality of care has improved since then. Study strengths include the use of a large, population-based registry, thus generalizability is probably high. In summary, this score can be used as a risk-stratification tool in determining treatment, and for informed consent, the authors said.

Five strategies associated with lower 30-day death rates for AMI

For patients with acute myocardial infarction (AMI), five hospital strategies are associated with significantly lower 30-day mortality rates, a recent survey found.

Researchers used a qualitative design to develop hypotheses about key hospital strategies that might be associated with lower 30-day risk-standardized mortality rates (RSMRs) for AMI, then tested the hypotheses in a national survey of 537 acute care hospitals. A knowledgeable staff member at each hospital completed a Web-based survey to assess that facility's use of the strategies. Four hospitals were excluded for lack of AMI data, leaving 533 in the final sample. Responding hospitals all had an annualized AMI volume of at least 25 patients; nearly 50% had an annualized volume of more than 125 patients. The weighted mean 30-day RSMR for all hospitals was 15.4% (standard deviation, 1.5%; range, 11.5% to 21.7%). Results were published in the May 1 Annals of Internal Medicine.

The strategies significantly associated with lower mortality rates included:

  • Having physician and nurse champions instead of only nurse champions (RSMR lower by 0.88 percentage point);
  • Having a culture where clinicians were encouraged to creatively solve problems (RSMR lower by 0.84 percentage point);
  • Holding meetings at least monthly between hospital clinicians and staff members who transport patients to the hospital, in order to review AMI cases (RSMR lower by 0.70 percentage point);
  • Having cardiologists always on site (RSMR lower by 0.54 percentage point); and
  • Not cross-training critical care nurses to work in the cardiac catheterization lab (RSMR lower by 0.44 percentage point).

Fewer than 10% of hospitals reported using at least four of these five strategies. A main limitation of the study is that an association between factors and RSMRs cannot be deemed causal, the authors said. The effect size of individual strategies was fairly modest, they noted, but the strategies in aggregate exceed an absolute difference of 1% in RSMRs. “If a change this large could be achieved nationally, thousands of lives could be saved yearly” through these low-risk interventions, most of which require few new resources, they wrote.

Performance measures released for in- and outpatient heart failure

Updated heart failure performance measures were released in May by three major medical groups and include changes to inpatient and outpatient care.

The changes to inpatient measures include:

Left ventricular systolic function. The new measures added a qualitative description of left ventricular ejection fraction (LVEF) to allow easier implementation of treatment-based measures.

Beta-blocker therapy for left ventricular systolic dysfunction (LVSD). The new measures added this to the inpatient setting and specified bisoprolol, carvedilol and sustained-release metoprolol succinate to harmonize treatment across settings. Starting these therapies is recommended in stable patients before hospital discharge.

Angiotensin-converting enzyme inhibitors (ACEs) or angiotensin receptor blockers (ARBs) for LVSD. The measure set combines inpatient and outpatient measures, defines “prescribed” to clarify which patients should be counted in the numerator, and simplifies exclusions. This harmonizes treatment across settings, clarifies which drugs should be used, and allows for patient preferences and clinical judgment.

Postdischarge appointment for heart failure patients. This is a new measure.

The report retired the measures on use of anticoagulants at discharge, discharge instructions and smoking cessation counseling because they have become a standard of care for broader populations.

Changes to outpatient measures include:

LVEF assessment. The description was modified because evaluation of LVEF in heart failure patients provides important information to direct appropriate treatment.

Symptom and activity assessment. Assessment of activity levels and assessment of clinical symptoms of volume overload were combined to provide a more comprehensive overview of patient status.

Symptom management. This new measure is intended as a quality metric.

Patient self-care education. This measure changed to a quality metric.

ACEs or ARBs for LVSD. Use of these classes of drugs remains suboptimal, especially in the outpatient setting.

Counseling about implantable cardioverter defibrillators (ICDs). This quality metric changed to a measure because ICDs have proved to be highly effective for preventing sudden death, but half of eligible patients don't undergo implantation.

Initial lab tests and weight measurement were retired because they have become a standard of care. Blood pressure measurement and assessment of volume overload were retired as measures because of poor evidence support. Warfarin for patients with atrial fibrillation was retired because it became part of a larger measure set for a broader population of patients.

The measures were released by the American College of Cardiology Foundation, the American Heart Association and the American Medical Association-Physician Consortium for Performance Improvement. They are available online at Circulation.

Med school slots still increasing

Increases in medical school enrollment are likely to almost meet the 30% target set by the Association of American Medical Colleges (AAMC) in 2006, according to recent projections.

According to a survey conducted by the AAMC's Center for Workforce Studies and released in May, first-year medical school enrollment is projected to reach 21,376 in the school year 2016-2017, a 29.6% increase over enrollment in 2002-2003, just short of the 30% increase by 2015 that the AAMC had called for.

Most of that growth (58%) will occur in the 125 schools that were already accredited in 2002. Schools that have been accredited since then will provide 25% of the increase, and the remainder (17%) will come from schools that are currently in applicant or candidate status with the Liaison Committee on Medical Education. More than half (56%) of the enrollment growth has already occurred, with 2,850 of the 4,888 slots available by 2011.

About 40% of the schools reported targeting their increases at underserved populations. Enrollment in Doctor of Osteopathic Medicine (DO) programs has risen particularly rapidly. First-year DO enrollment in 2016-2017 is projected to be 6,179, about double what it was in 2002-2003.

The survey also identified some concerns among medical school administrators:

  • 52% are concerned about the effects of the economic environment on enrollment,
  • 74% are concerned about the supply of qualified primary care preceptors, and
  • 53% are concerned about the supply of specialty preceptors.

The increase in students also raises concerns about residency slots. “If the number of entry level residency positions does not continue to increase, we may face a day when some qualified graduates of U.S. medical schools and osteopathic schools will be unable to find residency positions,” the authors wrote.

CDC: Fewer HAIs reported in 2010 than expected

Fewer health care-associated infections (HAIs) were reported to the Centers for Disease Control and Prevention (CDC) in 2010 than had been predicted based on 2006-2008 data, a recent report said. Specifically, the 2010 reported data show:

  • 13,812 central line-associated bloodstream infections (CLABSIs), compared to a prediction of 20,185 CLABSIs—a 32% difference;
  • 9,995 catheter-associated urinary tract infections (CAUTIs), compared to a predicted 10,657 CAUTIs—a 6% difference;
  • 4,737 deep incisional or organ/space surgical site infections (SSIs) during initial admission or on readmission, compared to a predicted 5,170 of these SSIs—an 8% difference.

CAUTIs occurred more frequently in critical care units than wards, the report said. For SSIs, improvement in prevention between 2009 and 2010 was seen most significantly for coronary artery bypass graft operations (18% of SSIs prevented in 2010). Stable reductions in SSIs were seen in two out of nine other operative procedures: an 11% reduction for knee arthroplasty and a 9% reduction for colon surgery.

An increasing number of hospitals are reporting data on infections generally, the report noted, as more states are mandating such reporting. For example, about 2,400 hospitals reported on CLABSIs by the end of 2010, a roughly 50% increase compared to 2009.