Biomedical subjects

Keith D Aaronson

Publications and source records attributed to Keith D Aaronson.

23 records · Page 2Linked to original sources

PubMed2003

Interaction study between digoxin and a preparation of hawthorn (Crataegus oxyacantha).

Hawthorn, an herbal supplement, is currently being evaluated for the treatment of heart failure. The flavonoid components of hawthorn may be responsible for hawthorn's beneficial effects in the treatment of heart failure. However, these components may also affect P-glycoprotein function and cause interactions with drugs that are P-glycoprotein substrates, such as digoxin, which is also used to treat heart failure. Therefore, the purpose of this study was to determine the effect of hawthorn on digoxin pharmacokinetic parameters. A randomized, crossover trial with 8 healthy volunteers was performed evaluating digoxin 0.25 mg alone (D) for 10 days and digoxin 0.25 mg with Crataegus special extract WS 1442 (hawthorn leaves with flowers; Dr. Willmar Schwabe Pharmaceuticals) 450 mg twice daily (D + H) for 21 days. Pharmacokinetic studies were performed for 72 hours. There were no statistically significant differences in any measured pharmacokinetic parameters. The AUC0-infinity, Cmax-Cmin, Cmin, and renal clearance for the D group were 79 +/- 26 mcg.h/L, 1.4 +/- 0.7 mcg/L, 0.84 +/- 0.2 mcg/L, and 74 +/- 10 mL/min versus 73 +/- 20 mcg.h/L, 1.1 +/- 0.1 mcg/L, 0.65 +/- 0.2 mcg/L, and 81 +/- 22 mL/min for the D + H group, respectively (p > 0.05). Following 3 weeks of concomitant therapy, hawthorn did not significantly alter the pharmacokinetic parameters for digoxin. This suggests that both hawthorn and digoxin, in the doses and dosage form studied, may be coadministered safely.

Adult↗

PubMed2002

Left ventricular assist device therapy improves utilization of donor hearts.

OBJECTIVES: We sought to determine the survival experiences of patients bridged to heart transplantation with either intravenous (IV) inotropes or an implantable left ventricular assist device (LVAD). BACKGROUND: Because of the operative risks of LVAD implantation and the reported lower mortality associated with inotropic therapy, bridging to heart transplantation with inotropes is thought to be the preferred treatment option. METHODS: Between April 1, 1996, and May 10, 2001, a total of 104 patients were bridged to heart transplantation with either IV inotropes (n = 38) or an implantable LVAD (n = 66; HeartMate). Survival was compared (Kaplan-Meier method) for three periods: survival to transplantation, post-transplantation survival and overall survival (i.e., survival from the onset of bridging to follow-up). RESULTS: Survival to transplantation was 81 +/- 5% at three months for the LVAD group and 64 +/- 11% for the inotrope group (p = NS). Post-transplantation survival was 95 +/- 4% at three years for the LVAD group (two deaths) and 65 +/- 10% at three years for the inotrope group (nine deaths; p = 0.007). Overall survival was 77 +/- 6% at three years for the LVAD group and 44 +/- 9% at three years for the inotrope group (p = 0.01). CONCLUSIONS: Overall survival for patients who were bridged to heart transplantation with an implantable LVAD was superior to that of patients who were bridged with inotropes. Bridging to transplantation with an implantable LVAD improves utilization of donor hearts.

Adolescent↗

PubMed2002

Safety and efficacy of atorvastatin in heart transplant recipients.

BACKGROUND: Pravastatin and simvastatin prolong survival and reduce transplant-related coronary vasculopathy, although low-density lipoprotein (LDL) lowering with these agents is only modest. The objective of this study was to assess the safety of moderate dose atorvastatin and its efficacy when prior treatment with another statin had failed to lower LDL to < 100 mg/dl. METHODS: Data from 185 patients were retrospectively evaluated for adverse events, duration of exposure (person-days), and the mean atorvastatin dose exposure. Changes in lipid parameters, and prednisone and cyclosporine doses were determined. RESULTS SAFETY: 48 patients received atorvastatin for 24,240 person-days at a mean dose exposure of 21 +/- 10 mg. Rhabdomyolysis, myositis, myalgias, and hepatotoxicity occurred in 0, 2, 2, and 0 patients, respectively. All events occurred at the 10-mg dose, within the first 3 months, and were rapidly reversible with atorvastatin discontinuation. EFFICACY: Thirty-four patients evaluable for efficacy analyses had a pre-atorvastatin LDL of 145 +/- 38 mg/dl on the following statins: pravastatin (n = 30, 40 +/- 0mg), fluvastatin (n = 3, 33 +/- 12 mg), simvastatin (n = 1, 40 mg). After atorvastatin (21 +/- 9 mg/day) for 133 +/- 67 days, LDL was reduced to 97 +/- 24 mg/dl (relative reduction 31 +/- 20%, p < 0.0001). At the end of the observation period (418 +/- 229 days, atorvastatin final dose 24 +/- 14 mg/day), LDL was further decreased to 88 +/- 23 mg (relative reduction 37 +/- 17%, p < 0.0001). CONCLUSION: Atorvastatin, when used at moderate doses and with close biochemical and clinical monitoring, appears to be safe and is effective in aggressively lowering LDL in heart transplant recipients when treatment with other statins has failed to achieve LDL goals.

Adult↗

PubMed2002

Prognostic significance of mitral regurgitation and tricuspid regurgitation in patients with left ventricular systolic dysfunction.

BACKGROUND: Mitral regurgitation (MR) and tricuspid regurgitation (TR) frequently develop in patients with left ventricular systolic dysfunction (LVSD). Ventricular volume overload that occurs in patients with MR and TR may lead to progression of myocardial dysfunction. We hypothesized that MR and TR would provide markers of risk in patients with LVSD. METHODS: We reviewed clinical, electrocardiographic, and echocardiographic data on 1421 consecutive patients with LVSD (left ventricular ejection fraction < or =35%). Predictors of survival (freedom from death or United Network for Organ Sharing [UNOS]-1 transplantation) were identified in a multivariable analysis with a Cox proportional hazards analysis. The impact of MR and TR (none to mild, moderate, or severe) then was assessed separately with Kaplan-Meier survival analysis. RESULTS: During the follow-up period (mean +/- SD, 365 +/-364 days), death occurred in 435 study subjects (31%) and UNOS-1 transplantation in 28 subjects (2%). Multivariable predictors of poor outcome included increasing MR and TR grade, cancer, coronary artery disease, and absence of an implantable cardiac defibrillator. Relative risk was 1.84 (95% CI 1.43-2.38) for severe MR and 1.55 (95% CI 1.14-2.11) for severe TR. Survival with Kaplan-Meier analysis related inversely to MR grade (none to mild 1004 +/-31 days, moderate 795 +/-34 days, severe 628 +/-47 days, P <.0001) and TR grade (none to mild 977 +/-28 days, moderate 737 +/-40 days, severe 658 +/-55 days, P =.0001). CONCLUSION: Patients with severe MR or TR represent high-risk subsets of patients with LVSD. Future study is warranted to determine whether pharmaceutical or surgical strategies to relieve MR and TR have a favorable impact on survival.

Cardiomyopathy, Dilated↗

PubMedDate not supplied

Barriers to constraining health care cost growth.

Managing health care cost growth is a fundamental challenge facing our health care system. Through analysis of semistructured interviews, we conclude that barriers to health plan-level cost containment activities and strong forces outside the control of individual health plans will prevent many health system reforms (such as more competition among plans or modest increases in patient copayments) from stemming health care cost inflation. Policy debates and budgetary discussions must recognize that health care cost growth in excess of gross domestic product (GDP) growth is likely inevitable in the foreseeable future. The policy focus should be directed toward encouraging value.

Cost Control↗