Effect of prolonged pressure equalization on final drifting during pressure wire studies.

Pressure drifting is a troublesome error in invasive coronary function tests. This study aimed to evaluate the relationship between prolonged and short-time pressure equalizations in pressure drifting. Pressure drifting was defined as the pressure gradient between the mean pressure of the distal wire sensor (Pd) and aortic pressure (Pa) when the wire was withdrawn to the tip of the guiding catheter. Significant drifts 1 and 2 were defined as the absolute values of pressure gradients > 2 and > 3 mmHg, respectively. A logistic regression model was used to evaluate the associations between prolonged pressure equalization and each pressure drifting. The prolonged pressure equalization strategy was associated with a lower incidence of drift 1 than the short-time pressure equalization strategy (6.84% vs. 16.92%, p < 0.05). However, no statistical differences were found in the incidence of drift 2 between the prolonged and short-time pressure equalization strategies (4.27% vs. 7.69%, p = 0.34). In the multivariable regression model, only the prolonged pressure equalization strategy predicted a lower incidence of pressure drift 1. In conclusion, the prolonged pressure equalization strategy was associated with a lower incidence of significant pressure drifting with more stringent thresholds than the short-time pressure equalization strategy.

Efficacy and Safety of High-Dose Intracoronary Adenosine Injection in Fractional Flow Reserve Assessment.

Background: The recommended dosage of intracoronary adenosine in fractional flow reserve (FFR) assessment is controversial. High-dose adenosine may overcome the biological variability of adenosine response in hyperemia. Objectives: We aimed to test the efficacy and safety of a high-dose escalation protocol at our institute. Methods: Using the adenosine dose escalation protocol, the percentages of FFR ≤ 0.75 and 0.80 after high-dose escalation were compared with those at conventional doses. The chi-squared test was used to evaluate the accuracy of FFR values with the tested doses by comparing them with the results of a non-invasive pretest. Results: A total of 87 patients (130 vessels) were included, and protocol adherence was 93.1%. High-dose intracoronary adenosine was injected in 78.5% of the vessels. The dose escalation strategy was well-tolerated without serious complications. The positive rate increased significantly after conducting the protocol compared to that with a conventional dose (28.2% vs. 23.6% with an FFR threshold of 0.75, and 48.7% vs. 42.5% with a threshold of 0.80, both p < 0.05). In the validation cohort, only FFR ≤ 0.75 was associated with the binary result of the non-invasive pretest (p < 0.01 vs. p = 0.37). The high-dose adenosine escalation strategy did not increase the accuracy of FFR (77.8% vs. 75.6% in conventional dose and high-dose adenosine, respectively). Conclusions: The use of a high-dose escalation strategy increased the positive rate in FFR assessments.

Deficiency of Endothelial Progenitor Cells Associates with Graft Thrombosis in Patients Undergoing Endovascular Therapy of Dysfunctional Dialysis Grafts.

BACKGROUND: The deficiency of endothelial progenitor cells has been demonstrated to be associated with cardiovascular events in patients undergoing dialysis. However, their correlation with dialysis graft outcomes remains unknown. The objective of this study was to investigate the relationship between circulating endothelial progenitor cells and dialysis graft outcomes. METHODS: After excluding 14 patients with acute coronary syndrome, decompensated heart failure or graft thrombosis in the prior three months, a total of 120 patients undergoing dialysis who underwent endovascular therapy of dysfunctional dialysis grafts were prospectively enrolled. Blood was sampled from study subjects in the morning of a mid-week non-dialysis day. Surface makers of CD34, KDR, and CD133 were used in combination to determine the number of circulating endothelial progenitor cells. All participants were prospectively followed until June 2013. RESULTS: The median follow-up duration was 13 months, within which 62 patients experienced at least one episode of graft thrombosis. Patients with graft thrombosis had lower CD34+KDR+ cell counts compared with patients without graft thrombosis (median 4.5 vs. 8 per 105 mononuclear cells, p = 0.02). Kaplan-Meier analysis demonstrated thrombosis-free survival was lower in the low CD34+KDR+ cell count group (30%) than in the high CD34+KDR+ cell count group (61%; p = 0.007). Univariate analysis showed diabetes, high sensitive C-reactive protein, lesion length and CD34+KDR+ cell counts associated with graft thrombosis. Multivariate analyses confirmed an independent association between low CD34+KDR+ cell counts and graft thrombosis (hazard ratio, 2.52; confidence interval, 1.43-4.44; p = 0.001). CONCLUSIONS: Our study demonstrated an independent association between low circulating endothelial progenitor cell counts and dialysis graft thrombosis.