Coronary artery calcification detection with invasive coronary angiography in comparison with unenhanced computed tomography.

OBJECTIVE: The presence of extensive coronary artery calcifications (CAC) influences treatment decisions, particularly for revascularization. However, important CAC might be missed with invasive coronary angiography (ICA). Our aim was to determine the accuracy of ICA in the identification of CAC using computed tomography (CT) as reference standard. PATIENTS AND METHODS: Overall, 349 consecutive patients who underwent both CT-based CAC-scoring and invasive coronary angiography within 60 days were retrospectively included. Two experienced operators classified CAC on ICA, without knowledge of CT-based CAC scoring, for each of the four main vessels as (0) absent, (1) mild, (2) moderate, or (3) dense calcifications. These scores were correlated with the CT-based Agatston CAC-scores, the noninvasive reference standard. The sensitivity, specificity, and accuracy of identified CAC using ICA were derived. Calcifications identified as moderate or dense on ICA or with a vessel-based Agatston score of more than 100 were considered important. RESULTS: CT classified 671 (48%) of the 1396 vessels as having moderately or densely calcified vessels (Agatston score >100), whereas this was 137 (9.8%) using ICA (P<0.001). A significant correlation was found between the CT-based and ICA-based CAC-scores for all vessels (P<0.001). The sensitivity in detecting any CAC by means of ICA was 43% with a specificity of 92% and an accuracy of 55%. The sensitivity of important CAC identification by ICA was 19%, the specificity 99%, and the accuracy 61%. CONCLUSION: The accuracy of ICA for the identification of calcifications is very low as only 19% of the relevant calcifications was identified. Preprocedural assessment of CAC with CT could be considered to improve the treatment approach.

Proniosomal transdermal therapeutic system of losartan potassium: development and pharmacokinetic evaluation.

The purpose of the current study was to investigate the feasibility of proniosomes as transdermal drug delivery system for losartan potassium. Different preparations of proniosomes were fabricated using different nonionic surfactants, such as Span 20, Span 40, Span 60, Span 80, Tween 20, Tween 40, and Tween 80. Different formulae were prepared and coded as PNG-1 (proniosomal gel-1) to PNG-7. The best in vitro skin permeation profile was obtained with proniosomal formulation PNG-2 in 24 h. The permeability parameters such as flux, permeability coefficient, and enhancement ratio were significant for PNG-2 compared with other formulations (P < 0.05). This optimized PNG-2 was fabricated in the form of transdermal patch using HPMC gel as a suitable base. Proniosomal transdermal therapeutic system (PNP-H) was found to be the optimized one as it gave better release of drug and better permeation in a steady-state manner over a desired period of time, that is, 24 h through rat skin. In vivo pharmacokinetic study of PNP-H showed a significant increase in bioavailability (1.93 times) compared with oral formulation of losartan potassium. The formulation appeared to be stable when stored at room temperature (30 +/- 2 degrees C) and at refrigeration temperature (4 +/- 2 degrees C) for 45 days.