Effect of Vitamin D and parathyroid hormone levels on the coronary slow-flow phenomenon.

BACKGROUND: The presence of vitamin D, and parathyroid hormone receptors has been demonstrated in the vascular endothelium. Variations in vitamin D, and parathyroid hormone levels may affect coronary flow and cause the coronary slow-flow phenomenon (CSF). METHODS: We enrolled 93 patients who had undergone coronary angiography and had near-normal coronary arteries. Blood samples were taken to determine the calcium, phosphorus, 25-hydroxy vitamin D, and parathyroid hormone levels. Vitamin D deficiency was defined as a serum 25-hydroxy vitamin D level of less than 20 ng/mL. We divided the study population into two groups according to thrombolysis in myocardial infarction frame count (TFC) levels. RESULTS: Patients with TFC ≤27 were in the control group (n = 39), and those with TFC >27 were in the CSF group (n = 54). 25-Hydroxy vitamin D levels were similar in both groups: 17.5 [3.3-36.1] ng/ml in the CSF group and 15.2 [5.3-34] ng/ml in the control group (P = 0.129). When we analyzed TFC for each of the coronary arteries, we found a weak negative correlation between vitamin D level and TFC of the right coronary artery in the CSF group (r = -0.314, P = 0.021). Parathyroid hormone levels were similar in both groups: 48 [16-140] pg/ml in the CSF group and 52 [25-125] pg/ml in the control group (P = 0.297). CONCLUSION: The study failed to demonstrate a relationship between serum parathyroid hormone level and CSF. However, a weak negative correlation was found between vitamin D level and TFC of the right coronary artery.

The impact of the extent and severity of coronary artery disease on fractional flow reserve measurements.

OBJECTIVE: Coronary angiography has a limitation to determine the severity of intermediate stenosis (30-70%)1,2. Fractional flow reserve (FFR) is a method for the assessment of the intermediate stenosis severity3. The effect of coronary artery disease (CAD) severity on the FFR results is not clear. In this study, we aimed to expose the effect of CAD severity calculated with Syntax and Gensini scores on FFR results. PATIENTS AND METHODS: We scanned patients data (n=378) who had undergone fractional flow reserve measurements in our center. Patients with acute coronary syndrome in the last month, moderate or severe valvular diseases, acute heart failure, serious bradycardia, atrial fibrillation/flutter, severe left ventricular hypertrophy or patient with deficient data were excluded. 351 patients were included in the study. Syntax and Gensini scores were calculated and compared with FFR results. Hemodynamically significant result for FFR, ratio <0.80 was accepted. RESULTS: The negative correlation between high Gensini, high Syntax scores and FFR results was statistically significant. Especially patients with Syntax scores >22 had notable more crucial lesions in FFR measurements (p<0.001). Cardiovascular disease risk factors such as age, gender, hypertension, diabetes mellitus and dyslipidemia did not correlate with the FFR results. Patients with intermediate stenosis (30-70%) and high Gensini and high Syntax scores were found to have more hemodynamically significant on FFR measurements (FFR <0.80). CONCLUSIONS: Intermediate lesions with high Syntax score should be evaluated by hemodynamic procedures and treated more carefully with optimal medical treatment or revascularization. Revascularization method of CAD with high Syntax score should be decided with hemodynamic procedures as FFR measurements.

Effect of LED and halogen light curing on polymerization of resin-based composites.

The clinical performance of light polymerized resin-based composites (RBCs) is greatly influenced by the quality of the light curing unit (LCU). A commonly used unit for polymerization of RBC material is the halogen LCUs. However, they have some drawbacks. Development of new blue superbright light emitting diodes (LED LCU) of 470 nm wavelengths with high light irradiance offers an alternative to standard halogen LCU. The aim of this study is compared the effectiveness of LED LCU and halogen LCU on the degree of conversion (DC) of different resin composites [two hybrid (Esthet-X, Filtek Z 250), four packable (Filtek P60, Prodigy Condensable, Surefil, Solitaire), one ormocer-based resin composite (Admira)]. The DC values of RBCs polymerized by LED LCU and halogen LCU ranged approximately from 61.1 +/- 0.4 to 50.6 +/- 0.6% and from 55.6 +/- 0.7 to 47.4 +/- 0.5%, respectively. Significantly higher DC of RBCs except Surefil and Filtek Z 250 was obtained for LED LCU compared with halogen LCU (P < 0.05). Surefil and Filtek Z 250 exhibited no statistically significant difference values between LED LCU and halogen LCU (P > 0.05). As a result, it was observed that the performance of LED LCU used in the study was satisfactory clinically and had sufficient irradiance to polymerize RBCs (hybrid, packable and ormocer based) at 2 mm depth with a curing time of 40 s.