Research Spotlight

Ernst, G., J. Canales and E. Garcia (2016). “Two novel methods to assess ulnar nerve conduction across the elbow.” J Electromyogr Kinesiol 30: 126-130.

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PURPOSE: Nerve conduction studies (NCS) are used as an electrodiagnostic method for diagnosing ulnar neuropathy of the elbow (UNE). The purpose of this study was to determine normal and reliability values of across elbow ulnar nerve conduction velocity using two novel methods. METHODS: Ulnar nerve conduction studies were performed on both upper extremities of 104 healthy subjects. Two different techniques were used to evaluate ulnar nerve function at the elbow: Technique 1 (W-BE-AE) determined mixed NCV across the elbow indirectly while Technique 2 (BE-AE) measured conduction time directly. Twenty subjects returned within one week for re-testing to generate reliability data. RESULTS: The mean NCV for the BE-AE segment using Technique 1 was 59.68m/s (+/-8.91m/s). The mean peak latency for the BE-AE segment using Technique 2 was 2.03ms (+/-0.24ms). The interrater and intrarater reliability intraclass correlation coefficient (ICC) for Technique 1 was 0.454 and 0.756, respectively. For Technique 2, the interrater and intrarater reliability ICC was 0.76 and 0.814, respectively. CONCLUSION: This study identified normal values for ulnar nerve conduction across the elbow with reliability ranging from poor to good, depending on the technique. These two novel techniques provide alternative methods to traditional techniques to measure ulnar nerve conduction across the elbow.

Schiattarella, G. G., A. Sannino, E. Toscano, F. Cattaneo, B. Trimarco, G. Esposito and C. Perrino (2016). “Cardiovascular effects of histone deacetylase inhibitors epigenetic therapies: Systematic review of 62 studies and new hypotheses for future research.” Int J Cardiol 219: 396-403.

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Based on the available published clinical trials reporting cardiovascular effects of HDACi therapy in cancer patients, 62 studies for a total patient population of 3268 were included to perform a systematic review according to PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) requirements. A further analysis was conducted to evaluate cardiovascular effects of the different drugs among the HDACi class. Overall, only a minority of studies reported cardiovascular effect of HDACi, and showed mild but frequent cardiovascular side effects after HDACi treatment in cancer patients.

Thourani, V. H., J. Forcillo, N. Beohar, D. Doshi, R. Parvataneni, G. M. Ayele, A. J. Kirtane, V. Babaliaros, S. Kodali, C. Devireddy, W. Szeto, H. C. Herrmann, R. Makkar, G. Ailawadi, S. Lim, H. S. Maniar, A. Zajarias, R. Suri, E. M. Tuzcu, S. Kapadia, L. Svensson, J. Condado, H. A. Jensen, M. J. Mack and M. B. Leon (2016). “Impact of preoperative chronic kidney disease in 2,531 high-risk and inoperable patients undergoing transcatheter aortic valve replacement in the partner trial.” Ann Thorac Surg 102(4): 1172-1180.

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BACKGROUND: Although preoperative renal dysfunction (RD) is associated with increased mortality and morbidity after surgical aortic valve replacement, its impact on clinical outcomes after transcatheter aortic valve replacement (TAVR) is less defined. METHODS: TAVR patients in the PARTNER (Placement of Aortic Transcatheter Valves) trial with a calculable glomerular filtration rate (GFR) using the Modification of Diet in Renal Disease equation were included. Patients were divided into three groups: GFR >60 mL/min (none/mild RD), GFR 31 to 60 mL/min (moderate RD), and GFR

Suri, R. M., S. Minha, O. Alli, R. Waksman, C. S. Rihal, L. P. Satler, K. L. Greason, R. Torguson, A. D. Pichard, M. Mack, L. G. Svensson, J. Rajeswaran, A. M. Lowry, J. Ehrlinger, S. L. Mick, E. M. Tuzcu, V. H. Thourani, R. Makkar, D. Holmes, M. B. Leon and E. H. Blackstone (2016). “Learning curves for transapical transcatheter aortic valve replacement in the partner-i trial: Technical performance, success, and safety.” J Thorac Cardiovasc Surg 152(3): 773-780.

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OBJECTIVES: Introduction of hybrid techniques, such as transapical transcatheter aortic valve replacement (TA-TAVR), requires skills that a heart team must master to achieve technical efficiency: the technical performance learning curve. To date, the learning curve for TA-TAVR remains unknown. We therefore evaluated the rate at which technical performance improved, assessed change in occurrence of adverse events in relation to technical performance, and determined whether adverse events after TA-TAVR were linked to acquiring technical performance efficiency (the learning curve). METHODS: From April 2007 to February 2012, 1100 patients, average age 85.0 +/- 6.4 years, underwent TA-TAVR in the PARTNER-I trial. Learning curves were defined by institution-specific patient sequence number using nonlinear mixed modeling. RESULTS: Mean procedure time decreased from 131 to 116 minutes within 30 cases (P = .06) and device success increased to 90% by case 45 (P = .0007). Within 30 days, 354 patients experienced a major adverse event (stroke in 29, death in 96), with possibly decreased complications over time (P approximately .08). Although longer procedure time was associated with more adverse events (P < .0001), these events were associated with change in patient risk profile, not the technical performance learning curve (P = .8). CONCLUSIONS: The learning curve for TA-TAVR was 30 to 45 procedures performed, and technical efficiency was achieved without compromising patient safety. Although fewer patients are now undergoing TAVR via nontransfemoral access, understanding TA-TAVR learning curves and their relationship with outcomes is important as the field moves toward next-generation devices, such as those to replace the mitral valve, delivered via the left ventricular apex.

Schussler, J. M., A. Vasudevan, L. J. von Bose, J. I. Won and P. A. McCullough (2016). “Comparative efficacy of transradial versus transfemoral approach for coronary angiography and percutaneous coronary intervention.” Am J Cardiol 118(4): 482-488.

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Transradial artery (TRA) approach is associated with fewer vascular complications and reduced mortality in patients at high risk compared with transfemoral approach (TFA). The objective of our study was to compare the characteristics and outcomes of patients who had coronary angiography by TRA and TFA over the course of hospital implementation of this approach. We included 12,928 patients from Baylor University Medical Center and Baylor Heart and Vascular Hospital, Dallas, Texas, who underwent a coronary angiography from January 2008 to March 2015. To control for selection bias and the learning curve, a nested matched study design was used for patients with percutaneous coronary intervention (PCI) with TRA patients matched with TFA by age (+/-2 years) and calendar year of the procedure in a ratio of 1:3. TRA for PCI increased from nearly 0% in 2008 to 9% in 2014. Including patients from 2011 to 2015 for the analysis, patients with TFA were older (65 +/- 12 vs 64 +/- 11) and had lower mean body mass index (30 +/- 7 vs 33 +/- 9 kg/m(2)) than patients with TRA. Patients with TRA had less bleeding, dialysis, pseudoaneurysm, and access site hematomas than the patients with TRA (0.7% vs 0%; p = 0.02). By a conditional logistic regression, we observed fewer complications, readmissions, and in-hospital deaths among TRA patients than the matched TFA patients. In conclusion, patients undergoing angiography with/without PCI through TRA had fewer complications, readmissions, and a shorter length of hospital stay after procedure versus TFA at our hospital.