Faculty Bibliography

Chelation therapy, typically used to remove heavy metal toxins, has also been controversially used as a treatment for coronary artery disease. The first Trial to Assess Chelation Therapy (TACT) aimed to provide evidence on chelation therapy's potential for benefit or harm. Although TACT had some significant results, the trial does not provide enough evidence to recommend routine chelation therapy and has limitations. The second TACT was recently funded reigniting a discussion about the value of chelation therapy, its efficacy, and allocation of research resources. Despite limited evidence, patients continue to pursue chelation therapy as a treatment for coronary artery disease. As the medical community has a responsibility to understand all treatments patients pursue, it is important to comprehensively appraise chelation therapy for cardiovascular disease. Understanding the background of heavy metal toxicity, the putative target of chelation therapy, on the cardiovascular system is important to contextualize the role of chelation therapy in cardiovascular disease prevention. We review the clinical evidence of heavy metal toxicity and cardiovascular disease, and available clinical trial data on use of chelation therapy to minimize the cardiovascular burden of heavy metal toxicity.

Aims: Post-stroke hypertension is associated with poor short-term outcome, although the results have been conflicting. Our objective was to evaluate the association of blood pressure (BP) and in-hospital outcomes in patients with acute ischaemic stroke. Methods and results: Patients in the Get With The Guidelines-Stroke registry with acute ischaemic stroke were included. Admission systolic and diastolic BP was used to compute mean arterial pressure (MAP) and pulse pressure (PP). The outcomes of interest were: in-hospital mortality, not discharged home, inability to ambulate independently at discharge and haemorrhagic complications due to thrombolytic therapy. A total of 309 611 patients with an ischaemic stroke were included. There was a J-shaped/U-shaped relationship between systolic BP and outcomes. Both lower and higher systolic BP values, compared with a central reference value, had higher risk of in-hospital death [e.g. adjusted odds ratio (95% confidence interval) (OR[CI]) = 1.16[1.13-1.20] for 120 vs. 150 mmHg and 1.24[1.19-1.30] for 200 vs. 150 mmHg], not discharged home (OR[CI] = 1.11[1.09-1.13] for 120 vs. 150 mmHg and 1.15[1.12-1.18] for 200 vs. 150 mmHg), inability to ambulate independently at discharge (OR[CI] = 1.16[1.13-1.18] for 120 vs. 150 mmHg and 1.09[1.06-1.11] for 200 vs. 150 mmHg). However, risk of haemorrhagic complications of thrombolytic therapy was lower with lower systolic BP (OR[CI] = 0.89[0.83-0.97] for 120 vs. 150 mmHg), while higher with higher systolic BP (OR[CI] = 1.21[1.11-1.32] for 200 vs. 150 mmHg). The results were largely similar for admission diastolic BP, MAP, and PP. Conclusion: In patients hospitalized with ischaemic stroke, J-shaped, or U-shaped relationships were observed between BP variables and short-term outcomes. However, haemorrhagic complications with thrombolytic therapy were lower with lower BP.

BACKGROUND: Practice patterns in anticoagulant strategies used during percutaneous coronary intervention (PCI) in the United States for patients with non-ST-segment-elevation myocardial infarction and the comparative outcomes between bivalirudin and unfractionated heparin (UFH) have not been well described. METHODS AND RESULTS: Trends in anticoagulant use were examined among 553 562 PCIs performed by 9254 operators at 1538 hospitals for non-ST-segment-elevation myocardial infarction from 2009 to 2014 within the CathPCI Registry. To compare bivalirudin with UFH, propensity score matching and instrumental variable (IV) methods with operator preference for bivalirudin as the instrument were used. To determine whether differences in outcomes were because of differences in glycoprotein IIb/IIIa inhibitor (GPI) use, a test of mediation was performed using the IV. Outcomes were in-hospital bleeding and mortality. Bivalirudin use increased from 2009 to 2013 but declined during 2014. GPI use was 50.5% during UFH PCIs and 12.0% during bivalirudin PCIs. Before GPI adjustment, bleeding reductions with bivalirudin ranged from 2.04% (IV: 95% confidence interval [CI]: 1.81%, 2.27%) to 2.29% (propensity score: 95% CI: 2.14%, 2.44%) and mortality reductions ranged from 0.16% (IV: 95% CI: 0.03%, 0.28%) to 0.25% (propensity score: 95% CI: 0.17%, 0.33%). After GPI adjustment in the IV, more than half the bleeding reduction with bivalirudin was because of the lower use of GPIs (risk difference, -0.84%; 95% CI: -1.11%, -0.57%), and no survival benefit was apparent (risk difference, -0.10%; 95% CI: -0.24%, 0.05%). Bleeding reductions with bivalirudin were largest for transfemoral PCI (GPI-adjusted risk difference, -1.11%; 95% CI: -1.43%, -0.80%) and negligible for transradial PCI (GPI-adjusted risk difference, 0.09%; 95% CI: -0.32%, 0.50%). CONCLUSIONS: In the largest comparative analysis of bivalirudin versus UFH for non-ST-segment-elevation myocardial infarction to date, bivalirudin was associated with lower in-hospital bleeding and mortality given current practices with respect to GPI use and access site. Bleeding differences were, in part, explained by the greater use of GPIs with UFH. Reductions in bleeding were largest among those undergoing transfemoral PCI, whereas no bleeding benefit was observed for those treated with transradial PCI.

Influenza B is a rare cause of myocarditis that is usually caused by histiocytic and mononuclear cellular infiltrates. We describe a 22-year-old female patient presenting with fulminant myopericarditis secondary to influenza B infection that deteriorated to cardiogenic shock. Endomyocardial biopsy results yielded myocardial necrosis through complement-mediated cellular injury without evidence of interstitial infiltrates. The rare cause of this patient's disease, along with the unique pathologic findings, are an important reminder of the diversity of potential findings in myocarditis.

BACKGROUND: Thyroid storm (TS) constitutes an endocrine emergency with an incidence of up to 10% of all admissions for thyrotoxicosis. Cardiogenic shock (CS) is a rare complication of TS and very limited data exists on its incidence and outcomes. We aimed to estimate the national trends in incidence and outcomes of CS among patients admitted to US hospitals with TS. MATERIALS AND METHODS: We queried the nationwide inpatient sample for patients with the discharge diagnosis of TS between the years of 2003 and 2011. RESULTS: Based on a weighted estimate, we identified 41,835 patients with a diagnosis of TS, of which 1% developed CS. Patients with CS were more likely to have history of atrial fibrillation, alcohol abuse, preexisting congestive heart failure, coagulopathy, drug use, liver disease, pulmonary circulation disorders, valvular disorders, weight loss, renal failure, fluid and electrolyte disorders as compared to those who did not develop CS (P < 0.001 for all). We observed an increase in incidence of CS from 0.5% in 2003 to 3% in 2011 and a decrease in mortality from 60.5% in 2003 to 20.9% in 2011 (Ptrend < 0.001 for both). CONCLUSIONS: We observed that CS is a rare complication of TS, which occurs more commonly in male patients with preexisting structural and atherosclerotic heart disease, and carries a very poor prognosis. Although incidence has increased over the years, mortality from CS has steadily declined.