Browsing by Author "Fudim, Marat"

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    Diaphragmatic Function in Cardiovascular Disease: JACC Review Topic of the Week
    (Elsevier, 2022-10-25) Salah, Husam M.; Goldberg, Lee R.; Molinger, Jeroen; Felker, G. Michael; Applefeld, Willard; Rassaf, Tienush; Tedford, Ryan J.; Mirro, Michael; Cleland, John G. F.; Fudim, Marat; Biomedical Engineering and Informatics, Luddy School of Informatics, Computing, and Engineering
    In addition to the diaphragm's role as the primary respiratory muscle, it also plays an under-recognized role in cardiac function. It serves as a pump facilitating venous and lymph return, modulating left ventricular afterload hemodynamics and pericardial pressures, as well as regulating autonomic tone. Heart failure (HF) is associated with diaphragmatic changes (ie, muscle fiber atrophy and weakness, increased ratio of type I to type II muscle fibers, and altered muscle metaboreflex) that lead to diaphragmatic dysfunction with subsequent symptomatic manifestations of HF. Herein, it is proposed that targeting the diaphragm in patients with HF via inspiratory muscle training or device-based stimulation can provide a novel treatment pathway for HF. Reviewed are several potential mechanisms through which therapies targeting the diaphragm can be beneficial in HF (ie, improving preload reserve, atrial and ventricular synchrony, and metaboreflex activity; reducing pericardial restraint; and restoring diaphragm strength).
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    Effect on Mortality of Higher Versus Lower β-Blocker (Metoprolol Succinate or Carvedilol) Dose in Patients With Heart Failure
    (Elsevier, 2018) Ajam, Tarek; Ajam, Samer; Devaraj, Srikant; Fudim, Marat; Kamalesh, Masoor; Medicine, School of Medicine
    This study aimed to compare the effect of β-blocker dose and heart rate (HR) on mortality in patients with heart failure with reduced ejection fraction (HFrEF). The Veteran Affairs databases were queried to identify all patients diagnosed with HFrEF based on International Classification of Diseases Ninth Revision codes from 2007 to 2015 and β-blocker (carvedilol or metoprolol succinate) use. 36,168 patients on low dose β blocker were then matched with 36,168 patients on high dose β-blocker using propensity score matching. The impact of β-blocker dose and HR was assessed on overall mortality using Cox proportional hazard model. After dividing average HR into separate quartiles and adjusting for patient characteristics, high β-blocker dose was associated with lower overall mortality as compared with a low dose of β blocker (hazard ratio 0.75, 95% confidence interval 0.73 to 0.77, p <0.01) independent of the HR achieved. The results held for all 4 quartiles of average HR. A higher β-blocker dose or a lower HR were independently and jointly associated with lower mortality for all quartiles of HR. In conclusion, higher dose of β-blocker therapy and a lower achieved HR were independently associated with a reduction in mortality in HFrEF patients.
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    Lower Post Myocardial Infarction Mortality among Women Treated at Veterans Affairs Hospitals Compared to Men
    (Elsevier, 2020-11) Ajam, Tarek; Devaraj, Srikant; Fudim, Marat; Ajam, Samer; Soleimani, Tahereh; Kamalesh, Masoor; Medicine, School of Medicine
    Background: There is conflicting evidence about whether mortality after myocardial infarction is higher among women than among men. This study aimed to compare sex differences in post myocardial infarction mortality in the Veterans Affairs system, a setting where the predominant subjects are men. Materials and methods: The Veterans Affairs Corporate Data Warehouse inpatient and laboratory chemistry databases were used to identify patients diagnosed with acute myocardial infarction from inpatient records from January 1st, 2005 to April 25th, 2015. Mortality data was obtained through the Veterans Affairs death registry. Results: A total of 130,241 patients were identified; 127,711 men (98%) and 2,530 women (2%). Men typically had more comorbidities including congestive heart failure (54% vs. 46%, P value < 0.001), diabetes mellitus (54% vs. 48%, P value < 0.001), and chronic kidney disease (39% vs. 28%, P value < 0.001). The peak troponin-I was significantly higher among men (16.0 vs. 10.7 ng/mL, P value = 0.03). The mean follow-up time was 1490.67 ± 8 days. After adjusting for differences in demographics and comorbidities, women had a significantly lower risk of mortality (hazard ration [HR]: 0.747, P value < 0.0001) as compared to men. Conclusions: In a health care system where the predominant subjects are men, women had better short- and long-term survival than men after an acute myocardial infarction. Further investigation is warranted to determine the reasons behind the improved outcomes in women post myocardial infarction in the veteran population.