Fractional flow reserve derived from microcatheters versus standard pressure wires: a stenosis level meta analysis

AbstrAct Aims To determine the agreement between sensor tipped microcatheter (MC) and pressure wire (PW)-derived fractional flow reserve (FFR). Methods and results Studies comparing FFR obtained from MC (FFRMC, Nav vus Microcatheter System, ACIST Medical Systems, Eden Prairie, Minnesota, USA) versus standard PW (FFRPW) were identified, and a meta-analysis of numerical and categorical agreement was performed. The relative levels of drift and device failure of MC and PW systems from each study were assessed. Six studies with 440 lesions (413 patients) were included. The mean overall bias between FFRMC and FFRPW was −0.029 (FFRMC lower). Bias and variance were greater for lesions with lower FFRPW (p<0.001). Using a cut-off of 0.80, 18 % of lesions were reclassified by FFRMC versus FFRPW (with 15 % being false positives). The difference in reported drift between FFRPW and FFRMC was small. Device failure was more common with MC than PW (7.1% vs 2%). Conclusion FFRMC systematically overestimates lesion severity, with increased bias in more severe lesions. Using FFRMC changes revascularisation guidance in approximately one out of every five cases. PW drift was similar between systems. Device failure was higher with MC. (AU)

Ethnicity and left ventricular diastolic function in hypertension an ASCOT (Anglo-Scandinavian Cardiac Outcomes Trial) substudy.

OBJECTIVES: We investigated whether diastolic function differs between hypertensive patients of African-Caribbean or white European origin and established whether differences could be explained by confounding variables. BACKGROUND: African Caribbeans are known to have a higher prevalence of heart failure than white Europeans but it is unclear whether this is a result of known risk factors. Tissue Doppler technology now allows accurate quantification of diastolic function, which is recognized as an important factor in the development of heart failure. METHODS: Participants from a single center participating in the ASCOT (Anglo-Scandinavian Cardiac Outcomes Trial), composed of patients with hypertension but no evidence of heart failure, were studied. Left ventricular structure and function were measured in 509 patients using conventional and tissue Doppler echocardiography. Diastolic function was assessed using the tissue Doppler early diastolic velocity E' (averaged from 3 left ventricular segments) and the ratio of this and the transmitral early filling velocity E (E/E'). RESULTS: In African-Caribbean patients, mean E' was significantly lower (7.7 cm/s vs. 8.6 cm/s, p = 0.003) and mean E/E' was significantly higher (8.85 vs. 7.93, p = 0.003). After adjustment for confounding variables-age, gender, systolic blood pressure, pulse pressure, cholesterol, smoking, ejection fraction, left ventricular mass index, and diabetes mellitus-the effect of African-Caribbean ethnicity on diastolic function remained highly significant (E': 7.52 vs. 8.51; p < 0.001; E/E': 8.89 vs. 7.93; p = 0.003; African Caribbeans vs. white Europeans for both comparisons). CONCLUSIONS: Diastolic function is significantly worse in hypertensive patients of African-Caribbean origin than in white Europeans. This difference in diastolic performance is not due to known confounding variables.