Difference In Fractional Flow Reserve Research Articles

Sex Differences in Fractional Flow Reserve– or Intravascular Ultrasound–Guided Percutaneous Coronary Intervention

BackgroundA recent randomized trial reported fractional flow reserve (FFR)-guided percutaneous coronary intervention (PCI) strategy was noninferior to the intracoronary ultrasound (IVUS)-guided PCI strategy with respect to clinical outcomes with fewer revascularizations. ObjectivesThis study sought to investigate the sex differences in treatment and clinical outcomes according to physiology- or imaging-guided PCI strategies. MethodsIn this secondary analysis of the FLAVOUR (Fractional Flow Reserve or Intravascular Ultrasonography to Guide PCI) trial, the impact of sex on procedural characteristics, PCI rate, and outcomes according to different strategies and treatment types (PCI vs deferral of PCI) was analyzed. The primary outcome was target vessel failure (TVF) at 24 months, defined as a composite of cardiac death, target vessel myocardial infarction, and target vessel revascularization. ResultsOf 1,619 patients, 30% were women. Compared with men, women had a smaller minimal lumen area, smaller plaque burden, and higher FFR. They had a lower PCI rate (40.8% vs 47.9%; P = 0.008), which was mainly contributed by FFR guidance. Overall, women showed a lower TVF rate (2.4% vs 4.5%). According to the treatment type, the cumulative incidence of TVF was lower in women than in men among those with the deferral of PCI (1.7% vs 5.2%). However, this trend was not observed in patients who underwent PCI. In both women and men, there were no differences in clinical outcomes between the FFR- and IVUS-guided strategies. ConclusionsIn cases of intermediate stenosis, despite receiving fewer interventions, women had more favorable outcomes than men. The use of FFR led to a lower PCI rate but had a similar prognostic value compared with IVUS in both women and men.

Differences in fractional flow reserve derived from coronary computed tomography angiography according to coronary artery bifurcation angle.

Differences in fractional flow reserve derived from coronary computed tomography angiography according to coronary artery bifurcation angle.

Sex-based difference in fractional flow reserve and its impact on clinical outcomes

Obesity is a real public health problem and is of growing concern. People are resorting to surgical or endoscopic means to fight against overweight and obesity. In recent years, there has been a marked increase in the use of these means and in particular the insertion of a gastric balloon which seems to present less risk than surgical methods. Renal complications from intragastric balloon placement are extremely rare. We report here the case of compression of the left renal vein revealed by lumbar pain and hematuria in an overweight 39-year-old woman who benefited from the balloon gastric placement one month before symptoms. The scanner made the diagnosis and showed a good evolution after the withdrawal of the balloon. This was a prespecified and retrospective analysis of all consecutive patients who underwent FFR assessment for intermediate coronary lesions between January 2014 and December 2015. The primary endpoint was defined as the 1-year composite of cardiac death, vessel-related myocardial infarction, and clinically-driven target vessel revascularization. In 1554 lesions (23% in women), FFR was lower in men [0.83 ±0.09 vs 0.85 ±0.08, P=.004] driven by LAD values (for LAD P < .001, LCx or RCA P> .40). In proximal lesions (PLs), FFR was lower in men [0.83 ±0.10 vs 0.85 ±0.08, P=.004] with comparable values in non-PLs [0.84 ±0.09 vs 0.85 ±0.08, P=.36]. In PLs, the primary endpoint was higher in women [HR(adjusted) 3.18 (1.08-9.37), P=.035] with comparable outcomes in non-PLs (P=.032 for interaction). In deferred lesions, the primary endpoint was higher in women [HR(adjusted) 2.73 (1.10-6.74), P=.03] with no differences in revascularized lesions across sex (P=.02 for interaction). Results were consistent when using propensity score matching analysis. There is a sex-based difference in FFR, particularly in stenoses subtending large myocardium, and more evident in deferred lesions.

A Computational Analysis of the Influence of a Pressure Wire in Evaluating Coronary Stenosis

Cardiovascular disease is one of the world’s leading causes of morbidity and mortality. Fractional flow reserve (FFR) was proposed in the 1990s to more accurately evaluate the functional severity of intermediate coronary stenosis, and it is currently the gold standard in cardiac catheterization laboratories where coronary pressure and flow are routinely obtained. The clinical measurement of FFR relies on a pressure wire for the recording of pressures; however, in computational fluid dynamics studies, an FFR is frequently predicted using a wire-absent model. We aim to investigate the influence of the physical presence of a 0.014-inch (≈0.36 mm) pressure wire in the calculation of virtual FFR. Ideal and patient-specific models were simulated with the absence and presence of a pressure wire. The computed FFR reduced from 0.96 to 0.93 after inserting a wire in a 3-mm non-stenosed (pipe) ideal model. In mild stenotic cases, the difference in FFR between the wire-absent and wire-included models was slight. The overestimation in severe case was large but is of less clinical significance because, in practice, this tight lesion does not require sophisticated measurement to be considered critical. However, an absence of the pressure wire in simulations could contribute to an over-evaluation for an intermediate coronary stenosis.

Impact of Sex Difference on the Discordance of Revascularization Decision Making Between Fractional Flow Reserve and Diastolic Pressure Ratio During the Wave-Free Period.

BackgroundSex difference in fractional flow reserve (FFR) and resting index has not been fully clarified. We sought to investigate the impact of sex on the discordance of revascularization decision making between FFR and diastolic pressure ratio during the diastolic wave‐free period (dPRWFP).Methods and ResultsA total of 759 angiographically intermediate lesions with 30% to 80% diameter stenosis by quantitative coronary angiography in 577 patients in whom FFR and dPRWFP were measured were investigated. dPRWFP was measured during the wave‐free window of 5 heart cycles at an independent core laboratory. FFR ≤0.80 and dPRWFP ≤0.89 were considered positive studies. A total of 164 vessels in 126 women (21.6%) and 595 vessels in 451 men (78.4%) were included. In lesions with negative dPRWFP, positive FFR was less frequently observed in women (13 of 73; 17.8%) than in men (97 of 286; 33.9%) (P=0.009). In lesions with positive dPRWFP, the frequency of negative FFR was observed in 22 of 91 vessels (24.2%) in women and 51 of 309 vessels (16.5%) in men, which did not reach statistical significance (P=0.098). In multivariable analyses, female sex was independently associated with FFR‐dPRWFP discordance both in negative dPRWFP cohort (odds ratio, 0.44; 95% CI, 0.21–0.98; P=0.036) and in positive dPRWFP cohort (odds ratio, 2.41; 95% CI, 1.17–4.96; P=0.017) after adjustment for age, weight, quantitative coronary angiography data, and baseline physiological indexes.ConclusionsThe frequency of FFR‐dPRWFP discordance was significantly associated with sex, which may indicate potential shift of optimal threshold of either FFR or dPRWFP, or both of them, according to sex.

830 FFR and NHPR Discordance in AS Population

Coronary physiology in aortic stenosis (AS) is affected by pathological alterations within epicardial and microcirculatory environments. The hyperaemic response in AS is attenuated, with increases in baseline coronary flow velocities. We assessed whether alterations in AS influenced discordance between fractional flow reserve (FFR) and alternate non-hyperaemic pressure ratios (NHPR). Forty-one patients with severe AS and angiographically confirmed CAD underwent invasive pressure-wire measurements. Data were extracted to derive FFR, instantaneous wave-free ratio (iFR), diastolic pressure ratio (DPR) and resting Pd/Pa. Data were compared against lesion matched historic non-AS controls. Physiological significance was determined as FFR<0.80, iFR/DPR<0.89 and Pd/Pa<0.92. Patients with AS were older (75.3±7.5 vs 62.5±10.4yrs, p<0.0001), but otherwise comparable to controls. Mean gradient was 44.3±11.6mmHg and DI was 0.23±0.04. In the AS cohort, mean FFR was 0.82±0.09, iFR was 0.84±0.1, DPR was 0.84±0.1 and Pd/Pa was 0.90±0.05. There were no significant differences in FFR and Pd/Pa between cohorts, although resting iFR and DPR were lower in AS patients (p=0.02). Discordance between FFR, Pd/Pa, iFR and DPR was 29%, 22% and 24% respectively in the AS cohort, compared with 25%, 22.5% and 22.5% in controls (p>0.05). Detailed analysis determined that almost all discordance in severe AS was in the NHPR+/FFR- group (92%, 100% and 90%, respectively), differing significantly from controls (40%, 33% and 33%) (p<0.05). Overall discordance rates between FFR and NHPR are similar between AS and controls however almost all discordance is in the NHPR+/FFR- quadrant. Therefore, NHPR indices may overestimate lesion severity in severe AS patients.

6113Gender differences in long-term outcomes in patients with deferred revascularization following fractional flow reserve assessment: international collaboration registry of physiologic evaluation

Abstract Background Studies of sex differences in fractional flow reserve (FFR) measurements have shown that in comparison with men, angiographic lesions of similar visual severity are less likely to be ischemia producing in women. Gender specific differences may influence revascularization decision making and prognosis after deferred revascularization following FFR measurement. Purpose This study sought to investigate the gender difference in long-term prognosis of patients of deferred revascularization following FFR assessment. Methods A total of 879 patients (879 vessels) with deferred revascularization with FFR &gt;0.75 who underwent FFR and CFR measurements were enrolled from 3 countries (Korea, Japan, and Spain). Long-term outcomes were assessed in 649 men and 230 women by the patient-oriented composite outcome (POCO, a composite of any death, any myocardial infarction [MI], and any revascularization). We applied inverse-probability weighting (IPW) based on propensity scores to account for differences at baseline between women and men (age, hypertension, hyperlipidemia, diabetes mellitus, lesion location, clinical status, FFR, Reference diameter, Diameter stenosis, lesion length). The median follow-up duration was 1855 days (745–1855 days). Results Median FFR values were 0.88 (0.83–0.93) in men and 0.89 (0.85–0.94) in women, respectively. The occurrences of POCO were significantly high in men compared with that in women (10.5% vs 4.2%, P=0.007). Kaplan–Meier analysis revealed that women had a significantly lower risk of POCO (χ2=7.2, P=0.007). Multivariate COX regression analysis revealed that age, male, diabetes mellitus, diameter stenosis, lesion length, and coronary flow reserve were independent predictors of POCO. After applying IPW, the hazard ratio of male for POCO was 2.20 (95% confidence interval: 1.12 to 4.33, P=0.023). Conclusion This large multinational study reveals that long-term outcome differs between women and men in favour of women after FFR-guided revascularization deferral. Acknowledgement/Funding None

TCT-606 Gender Differences in Fractional Flow Reserve after Percutaneous Coronary Intervention

TCT-606 Gender Differences in Fractional Flow Reserve after Percutaneous Coronary Intervention

A Randomized Trial Comparing the NeoVas Sirolimus-Eluting Bioresorbable Scaffold and Metallic Everolimus-Eluting Stents

ObjectivesThe authors sought to evaluate the safety and effectiveness of the NeoVas bioresorbable scaffold (BRS) compared with metallic drug-eluting stents. BackgroundBRS have the potential to improve very late outcomes compared with metallic drug-eluting stents, but some BRS have been associated with increased rates of device thrombosis before complete bioresorption. NeoVas is a new poly-l-lactic acid BRS that elutes sirolimus from a poly-D, l-lactide coating. MethodsEligible patients with a single de novo native coronary artery lesion with a reference vessel diameter 2.5 to 3.75 mm and a lesion length ≤20 mm were randomized 1:1 to NeoVas BRS versus cobalt-chromium everolimus-eluting stents (CoCr-EES). Angiographic follow-up was performed in all patients at 1 year. The primary endpoint was angiographic in-segment late loss (LL), and the major secondary endpoint was the rate of angina. Baseline and follow-up optical coherence tomography and fractional flow reserve were performed in a pre-specified subgroup of patients. ResultsThe authors randomized 560 patients at 32 centers to treatment with NeoVas (n = 278) versus CoCr-EES (n = 282). One-year in-segment LL with NeoVas and CoCr-EES were 0.14 ± 0.36 mm versus 0.11 ± 0.34 mm (difference 0.03 mm; upper 1-sided 97.5% confidence interval 0.09 mm; pnoninferiority < 0.0001; psuperiority = 0.36). Clinical outcomes at 1 year were similar in the 2 groups, as were the rates of recurrent angina (27.9% vs. 32.1%; p = 0.26). Optical coherence tomography at 1 year demonstrated a higher proportion of covered struts (98.7% vs. 96.2%; p < 0.001), less strut malapposition (0% vs. 0.6%; p <0.001), and a smaller minimal lumen area (4.71 ± 1.64 vs. 6.00 ± 2.15 mm2; p < 0.001) with NeoVas compared with CoCr-EES respectively, with nonsignificant differences in fractional flow reserve (0.89 ± 0.08 vs. 0.91 ± 0.06; p = 0.07). ConclusionsThe NeoVas BRS was noninferior to CoCr-EES for the primary endpoint of 1-year angiographic in-segment LL, and resulted in comparable 1-year clinical outcomes, including recurrent angina. (NeoVas Bioresorbable Coronary Scaffold Randomized Controlled Trial; NCT02305485)

TCT-718 Rate of Discrepancies and Differences in Fractional Flow Reserve on Intermediate Range Instantaneous Wave-Free Ratio Lesions: Results from a Single-center Registry

TCT-718 Rate of Discrepancies and Differences in Fractional Flow Reserve on Intermediate Range Instantaneous Wave-Free Ratio Lesions: Results from a Single-center Registry

TCT-137 Gender Differences in Fractional Flow Reserve after Percutaneous Coronary Intervention

TCT-137 Gender Differences in Fractional Flow Reserve after Percutaneous Coronary Intervention

A Parametric Study of the Effect of Arterial Wall Curvature on Non-Invasive Assessment of Stenosis Severity:Computational Fluid Dynamics Study

The effect of coronary arterial wall curvature on noninvasive assessment of stenosis severity was studied by examining the fractional flow reserve (FFR), pressure drop coefficient (CDP) and lesion flow coefficient (LFC) under different angles of curvature of the arterial wall models. Computational simulation of hyperemic blood flow in curved arteries with different angles of curvature (0°, 30°, 60°, 90° and 120°) was developed in three severe categories of stenosis of 70% (moderate), 80% (intermediate), and 90% (severe) area stenoses (AS) to evaluate the effect of curvature on FFR, CDP and LFC. The numerical study showed that for a given percentage of AS, the curvature of the arterial wall augmented the flow resistance in addition to the resistance caused by the stenosis. Also, there are significant differences in FFR, CDP and LFC between a straight and a curved section. With an increase in artery wall curvature from 0° to 120°, FFR significantly decreases by 5%, 8% and 20% in 70%, 80% and 90% AS respectively. For a fixed stenosis severity, CDP significantly increases, whereas LFC decreases as the angle of curvature changes from straight to curved section. We conclude that the significant differences in FFR, CDP and LFC confirms that the functional significance of stenosis assessed non-invasively could lead to misjudgment of its severity. This will notably influence the intermediate stenosis severity. So the arterial wall curvature should be considered when assessing the significance of stenosis as an alternative to FFR.

Epicardial Artery Stenosis with a High Index of Microcirculatory Resistance Is Frequently Functionally Insignificant as Estimated by Fractional Flow Reserve (FFR).

Objective Differences in microvascular integrity can diversely influence the functional assessment of epicardial coronary artery disease in each patient. We investigated the relevance of the index of microcirculatory resistance (IMR) and fractional flow reserve (FFR) of intermediate coronary lesions. Methods The IMR and FFR were measured in 67 intermediate coronary lesions of the left anterior descending artery of 67 patients, by using a pressure sensor/thermistor-tipped guidewire. Results To assess the differences in FFR in relationship to the IMR value, patients were divided into tertile IMR groups as follows: Low-IMR (n=22, IMR 14±3), Mid-IMR (n=23, IMR 21±2), and High-IMR (n=22, IMR 36±10). An analysis of variance showed that the High-IMR group had significantly higher FFR values (0.87±0.07) than the Low-IMR group (0.81±0.08) (p=0.03). Functionally significant lesions with FFR ≤0.8 accounted for 9% of lesions in the High-IMR group, 36% in the Low-IMR group and 22% in the Mid-IMR group (p=0.02). In the multivariate logistic analysis, the IMR value was an independent determinant of FFR ≤0.8 (p=0.03). Conclusion In patients with a high IMR, intermediate lesions as identified with visual estimation were more frequently functionally insignificant. The IMR can provide additional information in understanding the mismatch between the anatomical and functional severity of intermediate coronary stenosis.

Sex-Related Differences in Fractional Flow Reserve–Guided Treatment

Sex-specific differences affect the evaluation, treatment, and prognosis of coronary artery disease. We tested the hypothesis that long-term outcomes of fractional flow reserve (FFR)-guided percutaneous coronary intervention (PCI) are different between women and men. Consecutive 1090 patients, referred for PCI and undergoing FFR measurements at the Mayo Clinic between October 2002 and December 2009, were included in this registry study. Clinical events were compared between the sexes during a median follow-up of 50.9 months. Of all patients, women had higher FFR adjusted by visual coronary stenosis than men (P=0.03). The Kaplan-Meier percent of major adverse cardiac events at 5 years was 35% in women and 38% in men (P=0.54). Interestingly, in patients undergoing PCI with an FFR <0.75, the incidence of death or myocardial infarction was significantly higher in women than in men (hazard ratio, 2.16; 95% confidence interval, 1.04-4.51; P=0.04). Moreover, compared with patients with FFR >0.80, deferral of PCI for those with FFR between 0.75 and 0.80 was associated with an increased rate of major adverse cardiac events, particularly death or myocardial infarction in women (hazard ratio, 3.25; 95% confidence interval, 1.56-6.74; P=0.002) and revascularization in men (hazard ratio, 2.66; 95% confidence interval, 1.66-4.54; P<0.001). Long-term outcome differs between women and men undergoing FFR-guided PCI. Our data suggest that the sex-based treatment strategy is necessary to further optimize prognosis of patients with coronary artery disease.

TCT-607 Sex-related differences in fractional flow reserve guided treatment

Sex-specific differences affect the evaluation, treatment and prognosis of coronary artery disease. We tested the hypothesis that long-term outcomes of fractional flow reserve (FFR)-guided percutaneous coronary intervention (PCI) are different between women and men. Consecutive 1090 patients,

Coronary Microvascular Dysfunction After ST-Segment–Elevation Myocardial Infarction

Variable degrees of coronary microvascular dysfunction occur at the time of ST-segment–elevation myocardial infarction (STEMI) correlating with infarct size and long-term prognosis. Angiographic methods for assessing microvascular dysfunction in the cardiac catheterization laboratory at the time of STEMI include thrombolysis in myocardial infarction flow grade, thrombolysis in myocardial infarction frame count, and thrombolysis in myocardial infarction myocardial perfusion grade.1 More recently, coronary wire-based methods measuring Doppler-derived parameters, such as the coronary flow velocity reserve (CFVR), or measuring thermodilution-derived parameters, such as the index of microcirculatory resistance, have been shown to be more powerful predictors of acute left ventricular dysfunction, myocardial viability, and subsequent adverse outcomes.2,3 Article see p 207 Although it is widely accepted that the degree of microvascular dysfunction occurring in the myocardium subtended by the infarct-related vessel correlates with infarct size and prognosis, there has been some debate on whether more global microvascular dysfunction, involving myocardial regions not supplied by the infarct-related vessel, is present at the time of STEMI. For example, Uren et al4 performed positron emission tomography imaging in 13 patients with STEMI and found a decreased coronary flow reserve in the noninfarct-related vessel, which improved at 6-month follow-up. However, Ntalianis et al5 measured fractional flow reserve in a nonculprit vessel at the time of STEMI in 75 patients and again 1 month later and found no significant difference in fractional flow reserve or in index of microcirculatory resistance, which was measured in a subgroup, suggesting that the microvascular dysfunction resulting from STEMI is limited to the territory supplied by the infarct-related artery. In this issue of Circulation: Cardiovascular Interventions , van de Hoef et al6 report long-term follow-up in 100 patients presenting with STEMI, in whom they measured Doppler wire-derived CFVR, diastolic deceleration time, and systolic flow reversal …

Serial Morphological and Functional Assessment of Drug-Eluting Balloon for In-Stent Restenotic Lesions: Mechanisms of Action Evaluated With Angiography, Optical Coherence Tomography, and Fractional Flow Reserve

This study sought to elucidate the underlying mechanism through which drug-eluting balloons (DEB) restore coronary blood flow, by assessing the coronary vessel before, immediately after, and at 6-month follow-up with angiography, optical coherence tomography (OCT), and fractional flow reserve (FFR). In-stent restenosis (ISR) treatment remains challenging. Drug-eluting balloons have been shown to be a valid treatment option in several studies. These studies focused on efficiency of the device, whereas the mechanisms of action of DEB in ISR treatment have not been investigated. In this prospective, single-center observational study, patients with ISR were treated with a second-generation DEB. Serial angiographic, OCT, and FFR measurements were performed before and after the procedure, as well as at 6-month follow-up. Twenty-five patients were assigned to DEB treatment, with an angiographic and device success of 100% and 92%, respectively. Late luminal loss was 0.01 ± 0.43 mm. Median percent changes [interquartile range] between pre-and post-procedure, and post-procedure and follow-up were, respectively: lumen volume 75.1% increase [43.7 to 115.0], and 8% increase [-14.0 to 25.8]; stent volume 23.7% increase [15.5 to 40.0], and-1.2% decrease [-6.9 to 5.9]; and neointimal volume-14.4% decrease [-29.2 to-9.5], and-15.8% decrease [-38.1 to 28.3]. The FFR gradient along the treated stent (difference in FFR between the distal and the proximal stent edge) was 0.37±0.18 pre-procedure, 0.06 ± 0.04 post-procedure, and 0.05 ± 0.05 at follow-up. In all post-procedural OCT images, intrastent dissections were seen, which were sealed at follow-up OCT. DEB restore coronary blood flow by means of a short-term mechanical effect, causing anincrease in lumen and stent volumes and compression of neointimal hyperplasia (with intra-stent dissections). Due to the local drug effect, patency persists and may even improve at follow-up, withfurther increase in lumen volume, decrease in neointimal volume, and complete sealing of neointimal dissections.

Fractional flow reserve and myocardial viability as assessed by SPECT perfusion scintigraphy in patients with prior myocardial infarction

BackgroundIn patients with previous myocardial infarction (MI), assessment of myocardial viability and physiological significance of coronary artery stenoses are essential for appropriate guidance of revascularization. The aim of the study was to evaluate the relation between fractional flow reserve (FFR) and myocardial viability as assessed by gated SPECT MIBI perfusion scintigraphy in patients with previous MI undergoing elective PCI. MethodsThe study population consisted of 26 patients (mean age 55 ± 7 years; 21 male) with a previous MI and a significant coronary stenosis in a single infarct-related coronary vessel for which PCI was being performed. In all patients, FFR was evaluated before and immediately after PCI. SPECT imaging was done before and 3 ± 1 months after PCI. A region representing the MI was considered viable if MIBI uptake was ≥55% of the normal region. Improvement in perfusion after revascularization was considered achieved if perfusion abnormalities decreased by 5% or more and there was a decrease in segmental score of ≥1 in three segments in PCI-related vascular territory. ResultsExtent of perfusion abnormalities decreased from 32 ± 16% to 27 ± 19% after PCI (P < .001). In patients with myocardial viability in comparison to patients with no viability, there was significant difference in FFR before PCI (.57 ± .14 vs .76 ± .12, P = .002), despite almost the same values of diameter stenosis of infarct-related artery (63 ± 8% vs 64 ± 3%, respectively, P = .572). In addition, FFR prior to PCI was related to improvement in perfusion abnormalities after revascularization (P = .047), as well as with peak activity of creatine-kinase measured during previous MI (r = .56, P = .005). ConclusionLower values of FFR before angioplasty are associated with myocardial viability and functional improvement as assessed by SPECT perfusion scintigraphy.

The value of fractional and coronary flow reserve in predicting myocardial recovery in patients with previous myocardial infarction

The aim of the study was to evaluate the relation between fractional flow reserve (FFR) and simultaneously evaluated coronary flow reserve by thermodilution (CFRthermo), with the improvement of left ventricular (LV) function in patients with previous myocardial infarction (MI) undergoing percutaneous coronary intervention (PCI). Study population consisted of 46 patients (mean age 53 +/- 7 years; 36 male) with previous MI and significant coronary stenosis undergoing PCI of infarct-related coronary artery. In all patients, we evaluated FFR and CFRthermo by single pressure/thermo wire during maximal hyperaemia before and immediately after PCI. We performed echocardiographic assessment of LV ejection fraction before and 6 months after PCI. Dobutamine stress echocardiography test was also performed before PCI. LV functional improvement was observed in 33/46 (72%) of patients. In patients with LV functional recovery in comparison with patients with no recovery, there was a significant difference in FFR before PCI (0.56 +/- 0.14 vs. 0.70 +/- 0.07, P < 0.001), improvement of FFR (0.35 +/- 0.14 vs. 0.21 +/- 0.07, P < 0.001), improvement of CFRthermo (1.3 +/- 0.6 vs. 0.5 +/- 0.3, P < 0.001), and CFRthermo after PCI (2.6 +/- 0.7 vs. 2.0 +/- 0.4, P < 0.001). When only parameters evaluated before PCI were taken into account, FFR before angioplasty (P = 0.001) and dobutamine-assessed viability (P = 0.006) were the most significant multivariate predictors of myocardial recovery. When all significant univariate parameters were evaluated, the most significant independent predictors for improvement in myocardial function were the improvement of CFRthermo during angioplasty (P < 0.001) and FFR before angioplasty (P = 0.002). Simultaneous evaluation of FFR and CFRthermo provide significant complementary data on the improvement in myocardial function in patients with previous MI. However, the evaluation of FFR before angioplasty identifies viable myocardium that may recover following revascularization and may be used as an alternative to non-invasive testing.

Effect of rapamycin therapy on coronary artery physiology early after cardiac transplantation

Rapamycin has been shown to reduce anatomical evidence of cardiac allograft vasculopathy, but its effect on coronary artery physiology is unknown. Twenty-seven patients without angiographic evidence of coronary artery disease underwent measurement of fractional flow reserve (FFR), coronary flow reserve (CFR), and the index of microcirculatory resistance (IMR) within 8 weeks and then 1 year after transplantation using a pressure sensor/thermistor-tipped guidewire. Measurements were compared between consecutive patients who were on rapamycin for at least 3 months during the first year after transplantation (rapamycin group, n = 9) and a comparable group on mycophenolate mofetil (MMF) instead (MMF group, n = 18). At baseline, there was no significant difference in FFR, CFR, or IMR between the 2 groups. At 1 year, FFR declined significantly in the MMF group (0.87 +/- 0.06 to 0.82 +/- 0.06, P = .009) but did not change in the rapamycin group (0.91 +/- 0.05 to 0.89 +/- 0.04, P = .33). Coronary flow reserve and IMR did not change significantly in the MMF group (3.1 +/- 1.7 to 3.2 +/- 1.0, P = .76; and 27.5 +/- 18.1 to 19.1 +/- 7.6, P = .10, respectively) but improved significantly in the rapamycin group (2.3 +/- 0.8 to 3.8 +/- 1.4, P < .03; and 27.0 +/- 11.5 to 17.6 +/- 7.5, P < .03, respectively). Multivariate regression analysis revealed that rapamycin therapy was an independent predictor of CFR and FFR at 1 year after transplantation. Early after cardiac transplantation, rapamycin therapy is associated with improved coronary artery physiology involving both the epicardial vessel and the microvasculature.