Sun exposure influences the prognostic power of components of mineral metabolism in patients with coronary artery disease.

BACKGROUND AND AIM: Calcidiol (vitamin D metabolite) plasma levels vary with sun exposure (SE). However, it is not known if SE influences its prognostic ability. We have studied the effect of SE on plasma levels of the components of mineral metabolism (calcidiol, fibroblast growth factor-23 [FGF-23], parathormone [PTH], and phosphate [P]) and on their prognostic value in patients with coronary artery disease (CAD). METHODS AND RESULTS: We studied prospectively 704 patients with stable CAD. Clinical variables and baseline calcidiol, FGF-23, PTH, and P plasma levels were assessed. We divided the population in two subgroups, according to the period of plasma extraction: High SE (HSE) (April-September) and low SE (LSE) (October-March). The outcome was the development of acute ischemic events (acute coronary syndrome, stroke, or transient ischemic attack), heart failure, or death. Mean follow-up was 2.15 ± 0.99 years. Calcidiol and P levels were higher in HSE group. In the whole population, calcidiol (HR = 0.84 for each 5 ng/ml increase, 95% CI = 0.71-0.99; p = 0.038) and FGF-23 (HR = 1.14 for each 100 RU/ml increase, 95% CI = 1.05-1.23; p = 0.009) were predictors of the outcome, along with age, hypertension, body-mass index, peripheral artery disease, and P levels. In the LSE subgroup, calcidiol (HR = 0.75; 95% CI = 0.57-0.99; p = 0.034) and FGF-23 (HR = 1.34; 95% CI = 1.13-1.58; p = 0.003) remained as predictors of the outcome. In the HSE group calcidiol and FGF-23 had not independent prognostic value. CONCLUSIONS: In patients with stable CAD, low calcidiol and high FGF-23 plasma levels predict an adverse prognosis only when the sample is obtained during the months with LSE. SE should be taken into account in the clinical practice.

The use of the acute Pd/Pa drop after intracoronary nitroglycerin infusion to rule out significant FFR: CANICA (Can intracoronary nitroglycerin predict fractional flow reserve without adenosine?) multicenter study.

OBJECTIVE: Functional assessment of coronary artery stenosis is performed by measuring the fractional flow reserve (FFR) under hyperemic conditions (Adenosine). However, the use of adenosine portends limitations. OBJECTIVE: We sought to investigate the relationship and correlation between FFR and the Pd/Pa value obtained just after the intracoronary infusion (acute drop) of nitroglycerin (Pd/Pa-NTG) and if this parameter enhances diagnostic accuracy for FFR prediction compared to the resting baseline Pd/Pa. METHODS: We conducted a multicenter study including prospectively patients presenting intermediate coronary artery stenosis (30-70%) evaluated with pressure wire. Resting baseline Pd/Pa, Pd/Pa-NTG and FFR were measured. RESULTS: 283 patients (335 lesions) were included. Resting baseline Pd/Pa value was 0.72 to 1.0 (0.93 ± 0.04), Pd/Pa-NTG was 0.60 to 1.0 (0.87 ± 0.07) and FFR 0.55 to 1.0 (0.83 ± 0.08). The ROC curves for resting baseline Pd/Pa and for Pd/Pa-NTG, using a FFR ≤ 0.80 showed an AUC of 0.88 (95% CI: 0.84-0.92, P < 0.001) and 0.94 (95% CI: 0.92-0.96, P < 0.001) respectively. The optimal cutoff values of resting baseline Pd/Pa and Pd/Pa-NTG for an FFR > 0.80, were >0.96 and >0.88, respectively. These values were present in a 29.8% (n = 100) and a 47.1% (n = 158), of the total lesions. Scatter plots showed a better correlation and agreement points with Pd/Pa-NTG than resting baseline Pd/Pa. The cutoff value of Pd/Pa-NTG > 0.88 showed an excellent NPV (96.2% for FFR > 0.8 and 100% for FFR > 0.75) and sensitivity (95% for FFR > 0.8 and 100% for FFR > 0.75) which were consistently high across all the subgroups analysis. CONCLUSION: The cutoff value of acute Pd/Pa-NTG > 0.88 has a high NPV meaning adenosine-FFR can be avoided in almost half of lesions.