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Jeremias A.,Health Science University | Jeremias A.,Cardiovascular Research Foundation | Maehara A.,Cardiovascular Research Foundation | Maehara A.,Columbia University | And 27 more authors.
Journal of the American College of Cardiology | Year: 2014

Objectives This study sought to examine the diagnostic accuracy of the instantaneous wave-free ratio (iFR) and resting distal coronary artery pressure/aortic pressure (Pd/Pa) with respect to hyperemic fractional flow reserve (FFR) in a core laboratory-based multicenter collaborative study. Background FFR is an index of the severity of coronary stenosis that has been clinically validated in 3 prospective randomized trials. iFR and Pd/Pa are nonhyperemic pressure-derived indices of the severity of stenosis with discordant reports regarding their accuracy with respect to FFR. Methods iFR, resting Pd/Pa, and FFR were measured in 1,768 patients from 15 clinical sites. An independent physiology core laboratory performed blinded off-line analysis of all raw data. The primary objectives were to determine specific iFR and Pd/Pa thresholds with ≥90% accuracy in predicting ischemic versus nonischemic FFR (on the basis of an FFR cut point of 0.80) and the proportion of patients falling beyond those thresholds. Results Of 1,974 submitted lesions, 381 (19.3%) were excluded because of suboptimal acquisition, leaving 1,593 for final analysis. On receiver-operating characteristic analysis, the optimal iFR cut point for FFR ≤0.80 was 0.90 (C statistic: 0.81 [95% confidence interval: 0.79 to 0.83]; overall accuracy: 80.4%) and for PdPa was 0.92 (C statistic: 0.82 [95% confidence interval: 0.80 to 0.84]; overall accuracy: 81.5%), with no significant difference between these resting measures. iFR and PdPa had ≥90% accuracy to predict a positive or negative FFR in 64.9% (62.6% to 67.3%) and 48.3% (45.6% to 50.5%) of lesions, respectively. Conclusions This comprehensive core laboratory analysis comparing iFR and PdPa with FFR demonstrated an overall accuracy of ∼80% for both nonhyperemic indices, which can be improved to ≥90% in a subset of lesions. Clinical outcome studies are required to determine whether the use of iFR or PdPa might obviate the need for hyperemia in selected patients. © 2014 by the American College of Cardiology Foundation. Source


Johnson N.P.,University of Houston | Johnson D.T.,University of Houston | Kirkeeide R.L.,University of Houston | Berry C.,University of Glasgow | And 7 more authors.
JACC: Cardiovascular Interventions | Year: 2015

Objectives This study classified and quantified the variation in fractional flow reserve (FFR) due to fluctuations in systemic and coronary hemodynamics during intravenous adenosine infusion. Background Although FFR has become a key invasive tool to guide treatment, questions remain regarding its repeatability and stability during intravenous adenosine infusion because of systemic effects that can alter driving pressure and heart rate. Methods We reanalyzed data from the VERIFY (VERification of Instantaneous Wave-Free Ratio and Fractional Flow Reserve for the Assessment of Coronary Artery Stenosis Severity in EverydaY Practice) study, which enrolled consecutive patients who were infused with intravenous adenosine at 140 μg/kg/min and measured FFR twice. Raw phasic pressure tracings from the aorta (Pa) and distal coronary artery (Pd) were transformed into moving averages of Pd/Pa. Visual analysis grouped Pd/Pa curves into patterns of similar response. Quantitative analysis of the Pd/Pa curves identified the "smart minimum" FFR using a novel algorithm, which was compared with human core laboratory analysis. Results A total of 190 complete pairs came from 206 patients after exclusions. Visual analysis revealed 3 Pd/Pa patterns: "classic" (sigmoid) in 57%, "humped" (sigmoid with superimposed bumps of varying height) in 39%, and "unusual" (no pattern) in 4%. The Pd/Pa pattern repeated itself in 67% of patient pairs. Despite variability of Pd/Pa during the hyperemic period, the "smart minimum" FFR demonstrated excellent repeatability (bias -0.001, SD 0.018, paired p = 0.93, r2 = 98.2%, coefficient of variation = 2.5%). Our algorithm produced FFR values not significantly different from human core laboratory analysis (paired p = 0.43 vs. VERIFY; p = 0.34 vs. RESOLVE). Conclusions Intravenous adenosine produced 3 general patterns of Pd/Pa response, with associated variability in aortic and coronary pressure and heart rate during the hyperemic period. Nevertheless, FFR - when chosen appropriately - proved to be a highly reproducible value. Therefore, operators can confidently select the "smart minimum" FFR for patient care. Our results suggest that this selection process can be automated, yet comparable to human core laboratory analysis. © 2015 American College of Cardiology Foundation. Source


Johnman C.,University of Glasgow | Pell J.P.,University of Glasgow | Mackay D.F.,University of Glasgow | Behan M.,Royal Infirmary | And 3 more authors.
Heart | Year: 2012

Objective: To assess short-term and medium-term outcomes following radial and femoral artery access for primary or rescue percutaneous coronary intervention (PCI). Design: Retrospective cohort study. Setting: Scotland-wide. Patients: All 4534 patients undergoing primary or rescue PCI in Scotland between April 2000 and March 2009 using the Scottish Coronary Revascularisation Register. Intervention: Primary or rescue PCI. Main outcome measures: Procedural success; periprocedural complications; 30-day and 1-year mortality, myocardial infarction or stroke and long-term mortality. Results: Use of the radial approach increased from no cases in 2000 to 924 (80.5%) in 2009 (p<0.001). Patients in whom the radial approach was used were more likely to be male (p=0.041) and to have multiple comorbidities (p<0.001), including hypertension (p<0.001) and left ventricular dysfunction (p<0.001). They were less likely to have renal impairment (p=0.017), multi-vessel coronary disease (p=0.001) and cardiogenic shock (p<0.001). In multivariable analyses, use of radial artery access was associated with greater procedural success (adjusted OR 1.89, 95% CI 1.26-2.82, p=0.002) and a lower risk of any complications (adjusted OR 0.67, 95% CI 0.51-0.87, p=0.001) or access site bleeding complications (adjusted OR 0.21, 0.08-0.56, p-0.002), as well as a lower risk of myocardial infarction (adjusted OR 0.66, 95% CI 0.51-0.87, p=0.003) or death within 30 days (adjusted OR 0.51, 95% CI 0.04 - 0.52, p<0.001). The differences in myocardial infarction and death remained significant up to 9 years of follow-up. Conclusion: Use of the radial artery for primary or rescue PCI is associated with improved clinical outcomes. Source


Johnman C.,University of Glasgow | Mackay D.F.,University of Glasgow | Oldroyd K.G.,West of Scotland Regional Heart and Lung Center | Pell J.P.,University of Glasgow
Heart | Year: 2013

Objective: Overall, percutaneous coronary intervention (PCI) can improve the symptoms and quality of life (QoL) of patients with coronary artery disease. Older patients account for an increasing number and proportion of PCIs, however they are more prone to adverse events. This study systematically reviews the QoL benefits in this subgroup. Design and setting A systematic review was undertaken, in accordance with the Preferred Reporting Items for Systematic reviews and Meta-analysis (PRISMA) guidelines, using Medline, Embase and Science Direct databases. The search was limited to studies available in English; last run on 31 December 2012. Patients Patients aged ≥80 years. Intervention PCI. Main outcome measure QoL. Results: The process identified 11 articles which reported QoL outcomes in octogenarians following PCI. In total, there were 700 octogenarian patients identified within the 11 studies with a mean age of 82.9 years. Studies were heterogeneity in the populations, methodology and QoL tools utilised. Overall, the literature suggests that QoL for octogenarians improves following PCI. Older patients improve at least as much as younger patients and may gain more in the areas of physical functioning and improved angina status. The benefits are greatest in the first 6 months and may continue until at least 3 years. Conclusions: QoL following PCI in octogenarians improves at least as much as in younger patients. Given the small number of studies resulting in a total of 700 octogenarian patients, further studies would be useful in determining those octogenarian patients who are likely to derive the greatest benefit. Source


Berry C.,University of Glasgow | Berry C.,West of Scotland Regional Heart and Lung Center | Van 'T Veer M.,Catharina Ziekenhuis | Witt N.,Karolinska Institutet | And 10 more authors.
Journal of the American College of Cardiology | Year: 2013

Objectives: This study sought to compare fractional flow reserve (FFR) with the instantaneous wave-free ratio (iFR) in patients with coronary artery disease and also to determine whether the iFR is independent of hyperemia. Background: FFR is a validated index of coronary stenosis severity. FFR-guided percutaneous coronary intervention (PCI) improves clinical outcomes compared to angiographic guidance alone. iFR has been proposed as a new index of stenosis severity that can be measured without adenosine. Methods: We conducted a prospective, multicenter, international study of 206 consecutive patients referred for PCI and a retrospective analysis of 500 archived pressure recordings. Aortic and distal coronary pressures were measured in duplicate in patients under resting conditions and during intravenous adenosine infusion at 140 μg/kg/min. Results: Compared to the FFR cut-off value of ≤0.80, the diagnostic accuracy of the iFR value of ≤0.80 was 60% (95% confidence interval [CI]: 53% to 67%) for all vessels studied and 51% (95% CI: 43% to 59%) for those patients with FFR in the range of 0.60 to 0.90. iFR was significantly influenced by the induction of hyperemia: mean ± SD iFR at rest was 0.82 ± 0.16 versus 0.64 ± 0.18 with hyperemia (p < 0.001). Receiver operating characteristics confirmed that the diagnostic accuracy of iFR was similar to resting Pd/Pa and trans-stenotic pressure gradient and significantly inferior to hyperemic iFR. Analysis of our retrospectively acquired dataset showed similar results. Conclusions: iFR correlates weakly with FFR and is not independent of hyperemia. iFR cannot be recommended for clinical decision making in patients with coronary artery disease. (Comparison of Fractional Flow Reserve Versus Instant Wave-Free Ratio for Assessment of Coronary Artery Stenosis Severity in Routine Practice; NCT01559493) © 2013 American College of Cardiology Foundation. Source

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