Use of recombinant human parathyroid hormone in hypocalcemic cardiomyopathy

Hypocalcemia secondary to hypoparathyroidism is a rare cause of congestive heart failure. However, its early recognition and treatment lead to significant improvement in cardiac function. We report a middle-aged woman presenting with symptoms of heart failure with a serum calcium level of 3.7 mg/dl and a serum inorganic phosphate level of 17.6 mg/dl 22 years after subtotal thyroidectomy. Besides calcium and calcitriol supplementation, she was the first patient with severe hypocalcemic cardiomyopathy to be given off-label recombinant human parathyroid hormone (PTH) because of an elevated serum calcium-phosphate product. We discuss the management and outcome of the patient and then present a brief review of similar previously reported cases. We also describe the pivotal role of calcium ion and the potential role of PTH in maintaining myocardial contractility, effective natriuresis, and possible pathogenic mechanisms contributing to heart failure secondary to hypocalcemia and hypoparathyroidism.     

Evaluation of Care and Surveillance of Cardiovascular Disease: Can We Trust Medico-administrative Hospital Data?

Background

The evaluation of care and the surveillance of disease are important in respect to cardiovascular disease because it is prevalent and costly. In Canada, medico-administrative hospital data are readily available, continuously updated, and offer comprehensive coverage of the patient population. However, there is concern about the quality of the information.

Methods

The reliability and predictive capability of comorbidity data contained within Québec's hospital discharge database were assessed in comparison with data collected by clinical medical record reabstraction in a sample of 1989 patients hospitalized from 2002 to 2006 in a mix of 13 hospitals. Patients either had a principal diagnosis of myocardial infarction or underwent angioplasty or bypass surgery. Twenty-one comorbidities included in the Charlson comorbidity index or known to be associated with mortality were validated via medical record reabstraction.

Results

Of 14 comorbidities with > 2% prevalence, 8 had excellent agreement with medical record review (κ > 0.8) while 6 had substantial agreement (κ > 0.6). In general, positive predictive values were high, while measures of sensitivity were more variable. Univariate associations between comorbidities and 30-day and 1-year mortality were generally similar in the 2 data sources. Comorbidities retained in the final multivariate stepwise regression models from each data source were almost identical, as were the 2 models' abilities to predict mortality.

Conclusions

Hospital discharge data in Québec are, in general, reliably coded and compare favourably with clinical medical record review in their ability to predict mortality. It appears sufficiently reliable to provide useful information about clinical outcomes of cardiac care and to identify problems that warrant investigation.     

Evaluation of fluorescent plasma markers for in vivo microscopy of the microcirculation

This study evaluated four fluorescent-protein conjugates to monitor microcirculatory variables using the murine cremaster muscle and determined acute and long-term responses to repeated administration of FITC-BSA [conjugated at the University of Sheffield (UoS)] within a dorsal microcirculatory chamber (DMC) in rats. For analysis of the cremaster muscle, male C3H/HeN mice were anaesthetized, the cremaster muscle was exteriorized, then TRITC-BSA, TRITC-dextran, FITC-BSA, FITC-BSA (UoS) or FITC-dextran (0.25 ml/100 g) were administered systemically. The microcirculation was viewed with epi-illumination every 10 min for 120 min. For analysis of the DMC, male Wistar rats were implanted with the chamber. Three weeks later, FITC-BSA (UoS) was administered systemically, and the microcirculation response was monitored using three different protocols. In addition, in vitro stability of fluorescent conjugates was measured over 8 h. With regard to the cremaster muscle, initially no differences in interstitial fluorescence or vessel diameter were observed between the four fluorescent conjugates. By the end of the study, interstitial fluorescence from TRITC-dextran, FITC-dextran and FITC-BSA (Sigma) was significantly (p < 0.05) increased compared to FITC-BSA (UoS). With regard to the DMC, there was no interstitial fluorescence leakage after 180 min or 5 weeks despite repeated administration, but a significant (p < 0.05) leak was detected between 4 and 24 h. FITC-BSA (UoS) was the most stable fluorescent conjugate both in vitro and in vivo and was comparable with other conjugates for evaluating skeletal muscle microcirculation using fluorescent in vivo microscopy.