Motorized fractional flow reserve pullback : accuracy and reproducibility

Objectives: The present study aimed at determining the accuracy and reproducibility of motorized FFR pullbacks in patients with stable coronary artery disease. Background: Fractional flow reserve (FFR) is recommended for decision making regarding myocardial revascularization. The distribution of epicardial resistance along coronary vessels can be assessed using FFR pullbacks. Methods: Duplicated FFR pullbacks were acquired using a motorized device at a speed of 1 mm/s in intermediate coronary stenosis. In addition, a single FFR value was measured at an anatomical landmark. The agreement between FFR measurements was assessed using the Bland\u2013Altman method, Pearson's correlation coefficient and area under the pullback curve (AUPC). Results: In 20 vessels, 37,326 FFR values were obtained. The mean FFR from the pullbacks was 0.91 \ub1 0.08 whereas the mean FFR at the distal location was 0.85 \ub1 0.09. The mean difference between pullbacks was 120.002 (LOA 120.058 to 0.054). The difference in AUPC between the two FFR pullbacks was 2.1 \ub1 1.6%. At pre-specified anatomical locations, the mean difference between the FFR derived from the pullback data and the measured FFR was 0 (LOA 120.040 to 0.039). The repeatability of the distal FFR measurement was high (bias 120.003, LOA 120.046 to 0.041). Conclusion: A motorized FFR pullback was accurate to assess the distribution of epicardial resistance in patients with intermediate coronary artery disease. The reproducibility of the FFR pullback was high. Further studies are required to determine the potential usefulness of a hyperemic FFR pullback strategy for decision making and treatment planning

Diagnostic performance of exercise stress tests for detection of epicardial and microvascular coronary artery disease: the UZ Clear study.

Cardiac stress tests remain the cornerstone for evaluating patients suspected of having obstructive coronary artery disease (CAD). Coronary microvascular dysfunction (CMD) can lead to abnormal non-invasive tests. We sought to assess the diagnostic performance of exercise stress tests with indexes of epicardial and microvascular resistance as reference. This was a prospective, single-arm, multicentre study of patients with an intermediate pretest probability of CAD and positive exercise stress tests who were referred for invasive angiography. Patients underwent an invasive diagnostic procedure (IDP) with measurement of fractional flow reserve (FFR) and index of microvascular resistance (IMR) in at least one coronary vessel. Obstructive CAD was defined as diameter stenosis (DS) >50% by quantitative coronary angiography (QCA). The objective was to determine the false discovery rate (FDR) of cardiac exercise stress tests with both FFR and IMR as references. One hundred and seven patients (137 vessels) were studied. The mean age was 62.1±8.7, and 27.1% were female. The mean diameter stenosis was 37.2±27.5%, FFR was 0.84±0.10, coronary flow reserve was 2.74±2.07, and IMR 20.3±11.9. Obstructive CAD was present in 39.3%, whereas CMD was detected in 20.6%. The FDR was 60.7% and 62.6% with QCA and FFR as references (p-value=0.803). The combination of FFR and IMR as clinical reference reduced the FDR by 25% compared to QCA (45.8% vs 60.7%; p-value=0.006). In patients with evidence of ischaemia, an invasive functional assessment accounting for the epicardial and microvascular compartments led to an improvement in the diagnostic performance of exercise tests, driven by a significant FDR reduction

New insights on low vitamin D plasma concentration as a potential cardiovascular risk factor

The role of Vitamin D hormone in human health and disease is still debated. Recently, growing attention has been paid to its putative role in cardiovascular system homeostasis with several studies that suggested a correlation between low vitamin D levels and increased cardiovascular risk. Several mechanisms are involved in the development of cardiovascular diseases: systemic inflammation, endothelial dysfunction, arterial hypertension and insulin resistance. In the present paper, we have revised the current literature supporting a role for vitamin D in the development of these pathogenetic processes. Finally, we have evaluated the current evidence linking vitamin D to atherosclerosis and its natural consequence, cardiovascular diseases