Research Spotlight

Grover, F. L., S. Vemulapalli, J. D. Carroll, F. H. Edwards, M. J. Mack, V. H. Thourani, R. G. Brindis, D. M. Shahian, C. E. Ruiz, J. P. Jacobs, G. Hanzel, J. E. Bavaria, E. M. Tuzcu, E. D. Peterson, S. Fitzgerald, M. Kourtis, J. Michaels, B. Christensen, W. F. Seward, K. Hewitt and D. R. Holmes, Jr. (2016). “2016 annual report of the society of thoracic surgeons/american college of cardiology transcatheter valve therapy registry.” J Am Coll Cardiol: 2016 Dec [Epub ahead of print].

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BACKGROUND: The STS/ACC Transcatheter Valve Therapy (TVT) Registry captures all procedures with Food and Drug Administration (FDA) approved transcatheter valve devices performed in the United States and is mandated as a condition of reimbursement by a Centers for Medicaid and Medicare Services (CMS) OBJECTIVES: This annual report focuses on patient characteristics, trends, and outcomes of transcatheter aortic and mitral valve catheter-based valve procedures in the United States. METHODS: Data for all patients receiving commercially approved devices from 2012 through December 31, 2015 are entered in the TVT Registry. RESULTS: The 54,782 TAVR patients demonstrated decreases in expected risk of 30-day operative mortality (STS PROM) 7% to 6% and TAVR PROM (TVT PROM) 4% to 3% (both p<.0001) from 2012 to 2015. Observed in-hospital mortality decreased from 5.7% to 2.9% and one-year mortality decreased from 25.8% to 21.6. However, 30-day post procedure pacemaker insertion increased from 8.8% in 2013 to 12.0% in 2015. The 2,556 patients who underwent TMC in 2015 were similar to 2013-14 patients with hospital mortality of 2% with mitral regurgitation reduced to gradient /= 2 in 87% of patients (p<.0001). The 349 patients who underwent MViV and MViR procedures were high risk with, an STS PROM for MVR of 11%. The observed hospital mortality was 7.2% and 30-day post procedure was 8.5%. SUMMARY: The TVT Registry is an innovative registry that that monitors quality, patient safety and trends for these rapidly evolving new technologies. CONDENSED ABSTRACT: The STS/ACC TVT Registry captures all Food and Drug Administration (FDA) approved transcatheter valve devices preformed in the United States and is mandated as a condition for reimbursement by the Centers for Medicare Services. TAVR patients' expected risks of mortality and actual in-hospital mortality decreased. Transcatheter mitral clip procedures had a low mortality with reduced in mitral regurgitation to grade /= 2 in 87%. Mitral valve in valve or valve in ring patients were high risk for mortality, but actual hospital mortality was lower. The TVT Registry is an innovative registry that monitors quality, safety and trends of these evolving technologies.

Gomez-Hoyos, J., A. Khoury, R. Schroder, E. Johnson, I. J. Palmer and H. D. Martin (2017). “The hip-spine effect: A biomechanical study of ischiofemoral impingement effect on lumbar facet joints.” Arthroscopy 33(1): 101-107.

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PURPOSE: To assess the relation between ischiofemoral impingement (IFI) and lumbar facet joint load during hip extension in cadavers. METHODS: Twelve hips in 6 fresh T1-to-toes cadaveric specimens were tested. A complete pretesting imaging evaluation was performed using computed tomography scan. Cadavers were positioned in lateral decubitus and fixed to a dissection table. Both legs were placed on a frame in a simulated walking position. Through a posterior lumbar spine approach L3-4 and L4-5 facet joints were dissected bilaterally. In addition, through a posterolateral approach to the hip, the space between the ischium and the lesser trochanter was dissected and measured. Ultrasensitive, and previously validated, piezoresistive force sensors were placed in lumbar facet joints of L3-4 and L4-5. Lumbar facet loads during hip extension were measured in native hip conditions and after simulating IFI by performing lesser trochanter osteotomy and lengthening. Four paired t-tests were performed comparing normal and simulated IFI on the L3-L4 and L4-L5 facet joint loads. RESULTS: After simulating IFI, mean absolute differences of facet joint load were 10.8 N (standard error of the mean [SEM] +/-4.53, P = .036) for L3-4 at 10 degrees of hip extension, 13.71 N (SEM +/-4.53, P = .012) for L3-4 at 20 degrees of hip extension, 11.49 N (SEM +/-4.33, P = .024) for L4-5 at 10 degrees of hip extension, and 6.67 N (SEM +/-5.43, P = .245) for L4-5 at 20 degrees of hip extension. A statistically significant increase in L3-4 and L4-5 lumbar facet joint loads of 30.81% was found in the IFI state as compared with the native state during terminal hip extension. CONCLUSIONS: Limited terminal hip extension due to simulated IFI significantly increases L3-4 and L4-5 lumbar facet joint load when compared with non-IFI native hips. CLINICAL RELEVANCE: This biomechanical study directly links IFI to increased lumbar facet loads and supports the clinical findings of IFI causing lumbar pathology. Assessing and treating (open or endoscopic) hip disorders that limit extension could have benefit in patients with concomitant lower back symptoms.

Haskins, I. N., J. W. Fleshman, R. L. Amdur and S. Agarwal (2016). “The impact of bowel preparation on the severity of anastomotic leak in colon cancer patients.” J Surg Oncol 114(7): 810-813.

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BACKGROUND AND OBJECTIVES: The routine use of preoperative bowel preparation (BP) is heavily debated in the colorectal surgery literature. To date, no study has investigated the effect preoperative BP has on patients with an established anastomotic leak. We therefore seek to compare the severity of patient morbidity and mortality in patients with a known anastomotic leak based on type of preoperative BP using the Targeted Colectomy American College of Surgeons National Surgery Quality Improvement Program (ACS-NSQIP). METHODS: All elective colon cancer operations performed with primary anastomosis were identified within the targeted colectomy database from 2012 to 2013. Patients who experienced a postoperative anastomotic leak were identified and stratified based on preoperative BP. Variables that had an association with mechanical BP at P < 0.10 were included in a multivariate logistic regression model to determine if BP was independently associated with postoperative morbidity and mortality. RESULTS: A total of 6,297 patients underwent elective colon resection with primary anastomosis for colon cancer. Two hundred and nineteen (3.5%) patients experienced an anastomotic leak. Thirty-day wound morbidity and mortality was not worse in patients who underwent preoperative BP. CONCLUSIONS: BP is not associated with worse patients outcomes in those patients with an established anastomotic leak following elective colon research with primary anastomosis.

Henry, C., C. Boethel, L. A. Copeland, S. Ghamande, A. C. Arroliga and H. D. White (2017). “Clinical utility of testing for legionella pneumonia in central texas.” Ann Am Thorac Soc 14(1): 65-69.

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RATIONALE: Legionella pneumophila is an uncommon cause of community-acquired pneumonia in the south central region of the United States, and regular testing may not be cost effective in areas of low incidence. OBJECTIVES: To evaluate the incidence of Legionella in central Texas and to determine the cost effectiveness of Legionella urinary antigen testing. METHODS: We performed a single-center retrospective cohort study of patients admitted with pneumonia between January 2001 and December 2013. Patients were identified by Binax Legionella urinary antigen and International Classification of Disease, Ninth Revision codes. Demographic characteristics and clinical history of the confirmed Legionella pneumonia cases were obtained by chart review. Descriptive statistics were used to describe patient characteristics. MEASUREMENTS AND MAIN RESULTS: Over 12 years, 5,807 patients with 11,377 admissions for pneumonia were tested for Legionella urinary antigen. A positive Legionella urinary antigen was found in 17 patients. Cumulative incidence during the study period was 0.23%. Among the Legionella-positive patients, intensive care unit admission and median length of stay were 58.8% and 8.5 days, respectively. Most patients (64.7%) met American Thoracic Society criteria for severe pneumonia. All patients empirically received either a macrolide or fluoroquinolone covering Legionella. There were two in-hospital and three total 90-day deaths in those with a positive urinary antigen. The estimated cost of screening this population with Legionella urinary antigen was $214,438 over 13 years. CONCLUSIONS: This study reveals the low incidence of Legionella pneumonia in central Texas. Use of guideline-concordant antibiotic treatment provides coverage for Legionella. We speculate that testing in a low-prevalence area would not influence outcomes or be cost effective.

Nadruz, W., Jr., B. L. Claggett, J. J. McMurray, M. Packer, M. R. Zile, J. L. Rouleau, A. S. Desai, K. Swedberg, M. Lefkowitz, V. C. Shi, M. F. Prescott and S. D. Solomon (2016). “Impact of body mass index on the accuracy of n-terminal pro-brain natriuretic peptide and brain natriuretic peptide for predicting outcomes in patients with chronic heart failure and reduced ejection fraction: Insights from the paradigm-hf study (prospective comparison of arni with acei to determine impact on global mortality and morbidity in heart failure trial).” Circulation 134(22): 1785-1787.

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The design and primary results of the PARADIGM-HF trial have been previously described.5 The patients randomized in the trial (n=8399) were required to have a plasma BNP ≥150 pg/mL or an NT-proBNP ≥600 pg/mL or, if they were hospitalized for HF within the previous 12 months, a BNP ≥100 pg/mL or an NT-proBNP ≥400 pg/ mL. The present study included patients with available BMI data and who had BNP and NT-proBNP locally measured at the time of screening (n=8217). It considered the primary outcome of the PARADIGM-HF trial, the composite of death from cardiovascular causes or a first hospitalization for HF, as the study outcome. The patients were categorized into 4 groups according to BMI: <25.0 (nonoverweight/obese; n=2536); 25.0 to 29.9 (overweight; n=3116); 30.0 to 34.9 (obese; n=1694); and ≥35.0 kg/m2 (moderately/severely obese; n=871). BNP and NT-proBNP were divided into quartiles within the whole studied population. The trial was approved by the ethics committee at each participating institution, and all the patients provided written informed consent.