Research Spotlight

Posted July 15th 2018

Bioimpedance-Guided Hydration for the Prevention of Contrast-Induced Kidney Injury: The HYDRA Study.

Peter McCullough M.D.

Peter McCullough M.D.

Maioli, M., A. Toso, M. Leoncini, N. Musilli, G. Grippo, C. Ronco, P. A. McCullough and F. Bellandi (2018). “Bioimpedance-Guided Hydration for the Prevention of Contrast-Induced Kidney Injury: The HYDRA Study.” J Am Coll Cardiol 71(25): 2880-2889.

Full text of this article.

BACKGROUND: Intravascular volume expansion plays a major role in the prevention of contrast-induced acute kidney injury (CI-AKI). Recommended standard amounts of fluid infusion before procedures do not produce homogeneous responses in subjects with different initial hydration status. OBJECTIVES: The goal of this study was to compare the effect of standard and double intravenous (IV) infusion volumes in patients with low body fluid level, assessed by using bioimpedance vector analysis (BIVA), on the incidence of CI-AKI after elective coronary angiographic procedures. METHODS: A total of 303 patients with low BIVA level on admission were randomized to receive standard volume saline (1 ml/kg/h for 12 h before and after the procedure) or double volume saline (2 ml/kg/h). Patients (n = 715) with an optimal BIVA level received standard volume saline and were included in a prospective registry. The saline infusion was halved in all patients with an ejection fraction <40%. BIVA was repeated immediately before the angiographic procedure in all patients. CI-AKI was defined as an increase in levels of cystatin C >/=10% above baseline at 24 h after contrast administration. RESULTS: The incidence of CI-AKI was significantly lower (11.5% vs. 22.3%; p = 0.015) in patients receiving double volume saline than in those receiving standard volume saline, respectively. Before the angiographic procedure, 50% of the double volume patients achieved the optimal BIVA level compared with only 27.7% in the standard group (p = 0.0001). The findings were consistent in all the pre-specified subgroups excluding patients with a left ventricular ejection fraction <40% (p for interaction = 0.01). CONCLUSIONS: Evaluation of BIVA levels on admission in patients with stable coronary artery disease allows adjustment of intravascular volume expansion, resulting in lower CI-AKI occurrence after angiographic procedures. (Personalized Versus Standard Hydration for Prevention of CI-AKI: A Randomized Trial With Bioimpedance Analysis; NCT02225431).


Posted July 15th 2018

RESPONSE: Heart Team Training Results in Improved Care and Lasting Relationships: Room for Growth.

Michael J. Mack M.D.

Michael J. Mack M.D.

Mack, M. J. and D. R. Holmes, Jr. (2018). “RESPONSE: Heart Team Training Results in Improved Care and Lasting Relationships: Room for Growth.” J Am Coll Cardiol 71(23): 2704-2705.

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The multidisciplinary team-based approach to medical care is, of course, not new. There are numerous examples where specialists from different disciplines have collaborated to deliver integrated, disease-based care. Examples include tumor boards where medical oncologists, radiation therapists, surgeons, and other specialties team together to determine best treatment options for individual patients. The field of organ transplantation also includes a collaborative team-based approach with multiple medical specialties focused on delivering best patient care. The multidisciplinary approach to cardiac care is also not new, as we are reminded by Dr. Robert Frye from the Mayo Clinic that interdisciplinary team-based care was standard practice in the 1950s. After decades of underemployment, the “heart team” has re-emerged over the past decade and a half to create an integrated culture of care for various cardiac diseases . . . One of the benefits of this approach that was not obvious in the early stages, at least to us, was its potential effect on cardiac surgical training. Around the same time as the heart team re-emerged in 2007, a new program for training cardiac surgeons was created. The “I-6” pathway was developed with 2 goals: to shorten the time required to complete surgical training, and to focus the trainees’ experience more on cardiac and thoracic diseases and less on general surgery as in the traditional cardiac surgery training programs. As can be seen from the experience detailed above by Drs. Han and Brown, these 2 paradigm shifts, implementation of the heart team and creation of the I-6 programs, have become synergistic in training the new generation of cardiovascular surgeons. The integrated, team-based approach to patient care as a consequence of the heart team has served as an optimal training platform for the latest generation of cardiac surgeons. However, the authors relate that the benefits have exceeded just the educational experience by creating a cultural environment that has also led to the development of close professional and personal relationships. (Excerpt from text, p. 2704; no abstract available.)


Posted July 15th 2018

Minimum Detectable Measurement Difference for Health-Related Quality of Life Measures Varies With Age and Disability in Adult Spinal Deformity: Implications for Calculating Minimal Clinically Important Difference.

Richard Hostin M.D.

Richard Hostin M.D.

Kelly, M. P., H. J. Kim, C. P. Ames, D. C. Burton, L. Y. Carreon, D. W. Polly, Jr., R. Hostin, A. Jain, J. L. Gum, V. Lafage, F. J. Schwab, C. I. Shaffrey, J. S. Smith and S. Bess (2018). “Minimum Detectable Measurement Difference for Health-Related Quality of Life Measures Varies With Age and Disability in Adult Spinal Deformity: Implications for Calculating Minimal Clinically Important Difference.” Spine (Phila Pa 1976) 43(13): E790-e795.

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STUDY DESIGN: Retrospective cohort. OBJECTIVE: To investigate the minimum detectable measurement difference (MDMD) in the Scoliosis Research Society-22r (SRS-22r) outcomes instrument in adult spinal deformity (ASD) and to evaluate the effect of baseline data on measurable difference. SUMMARY OF BACKGROUND DATA: The minimum clinically important difference (MCID) is the smallest, clinically relevant change observed and has been proposed for the SRS-22r instrument in ASD as 0.4. The MCID must be greater than the MDMD to be useful. The MDMD for the SRS-22r has not been calculated, nor have the effect of patient baseline values on MDMD. METHODS: A prospective observation cohort was queried for patients treated both operatively and nonoperatively for ASD. Patients with baseline and 1-year, 2-year follow-up SRS-22r data were included in the analysis. The MDMD was calculated using classical test theory and item-response theory methods. Effect size and standardized response means were calculated. The effect of baseline data values was evaluated for MDMD. RESULTS: A total 839 Patients were eligible for cohort inclusion with 428 (51%) eligible for analysis with complete data. MDMD for Pain (0.6) and Self-Image (0.5) were greater than 0.4. MDMD varied with age (highest for the youngest patients) and with disability (highest for SF-36 Physical Component Summary <28.6). MDMD was less than 0.4 for Activity (0.3), Mental Health (0.3), and Total Score (0.2). Gender and mental health did not affect MDMD for the SRS-22r instrument. CONCLUSION: An MCID of 0.4 for the SRS-22r total score and domain scores may not be an appropriate value as the calculated MDMD is greater than 0.4 for both the Pain and Self-Image subscores. The MDMD for the SRS-22r instrument varied with age and baseline disability, making the assessment of clinically significant change more difficult using this tool. The MCID must be considered in the setting of the MDMD for instruments used to assess outcomes in ASD. LEVEL OF EVIDENCE: 3.


Posted July 15th 2018

Achilles tendon injury in patients taking quinolones.

Naohiro Shibuya D.P.M.

Naohiro Shibuya D.P.M.

Jupiter, D. C., X. Fang, Z. Ashmore, N. Shibuya and H. B. Mehta (2018). “The relative risk of Achilles tendon injury in patients taking quinolones.” Pharmacotherapy Jul 4. [Epub ahead of print].

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OBJECTIVE: To examine the association between quinolone use and Achilles tendon injury, comparing well matched cohorts of users of quinolone and non-quinolone antibiotics, and well matched cohorts of quinolone users and patients not using any non-quinolone antibiotics. PATIENTS AND METHODS: This retrospective cohort study used Clinformatics data from 2008 to 2014. Using propensity score, we matched quinolone users with other antibiotic users, and quinolone users with non-users. The primary outcome was Achilles tendon injury within 6 months. Bivariate analyses determined risk factors for Achilles tendon injury, and conditional logistic regression assessed impact of quinolone use on these injuries. RESULTS: Fluoroquinolone users (N=716,522) were matched with other antibiotic users, and fluoroquinolone users (N=645,034) were matched with non-users. Rates of Achilles tendon injury were less than 0.5% in all groups. Quinolone use increased risk of Achilles tendon injury compared to other antibiotic users (OR 1.24, 95% CI 1.17-1.31), and non-users (OR 1.54, 95% CI 1.44-1.64). Interaction with age did not significantly impact the relationship between quinolone use and Achilles injury; however, older quinolone users had slightly higher relative risk of injury than non-users vs. younger patients. Further, the youngest group of patients had similarly elevated relative risk for injury with quinolone use as did the elderly. CONCLUSION: While quinolone use increases risk of Achilles tendon injury, the absolute risk increase is minimal, especially when compared to similar morbidity patients taking other non-quinolone antibiotics. In relatively healthy populations, such as the one studied here, quinolone use may not make a clinically significantly contribution to risk of Achilles tendon injury, at any age range, among those in need of such drugs.


Posted July 15th 2018

Direct comparison of the thioacetamide and azoxymethane models of Type A hepatic encephalopathy in mice.

Victoria A. Jaeger D.O.

Victoria A. Jaeger D.O.

Grant, S., M. McMillin, G. Frampton, A. D. Petrescu, E. Williams, V. Jaeger, J. Kain and S. DeMorrow (2018). “Direct comparison of the thioacetamide and azoxymethane models of Type A hepatic encephalopathy in mice.” Gene Expr Jun 12. [Epub ahead of print].

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Acute liver failure is a devastating consequence of hepatotoxic liver injury that can lead to the development of hepatic encephalopathy. There is no consensus on the best model to represent these syndromes in mice and therefore the aim of this study was to classify hepatic and neurological consequences of azoxymethane- and thioacetamide-induced liver injury. Azoxymethane-treated mice were euthanized at time points representing absence of, minor and significant stages of neurological decline. Thioacetamidetreated mice had tissue collected at up to 3 days following daily injections. Liver histology, serum chemistry, bile acids and cytokine levels were measured. Reflexes, grip strength measurement and ataxia were calculated for all groups. Brain ammonia, bile acid levels, cerebral edema and neuroinflammation were measured. Finally, in vitro and in vivo assessments of blood-brain barrier function were performed. Serum transaminases and liver histology demonstrate that both models generated hepatotoxic liver injury. Serum proinflammatory cytokine levels were significantly elevated in both models. Azoxymethanetreated mice had progressive neurological deficits while thioacetamide-treated mice had inconsistent neurological deficits. Bile acids and cerebral edema were increased to a higher degree in azoxymethane-treated mice, while cerebral ammonia and neuroinflammation were greater in thioacetamide-treated mice. Blood-brain barrier permeability exists in both models but was likely not due to direct toxicity of azoxymethane or thioacetamide on brain endothelial cells. In conclusion, both models generate acute liver injury and hepatic encephalopathy but the requirement of a single injection and the more consistent neurological decline makes azoxymethane treatment a better model for acute liver failure with hepatic encephalopathy.