Repeatability of Fractional Flow Reserve Despite Variations in Systemic and Coronary Hemodynamics

ObjectivesThis study classified and quantified the variation in fractional flow reserve (FFR) due to fluctuations in systemic and coronary hemodynamics during intravenous adenosine infusion.BackgroundAlthough 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.MethodsWe 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.ResultsA 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).ConclusionsIntravenous 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.     

The Impact of Downstream Coronary Stenosis on Fractional Flow Reserve Assessment of Intermediate Left Main Coronary Artery Disease: Human Validation

ObjectivesThe aim of this study was to determine the impact of downstream coronary stenosis in the left anterior descending coronary artery (LAD) or left circumflex coronary artery (LCx) on the assessment of fractional flow reserve (FFR) across an intermediate left main coronary artery (LMCA) stenosis in humans with the pressure wire positioned in the nondiseased downstream vessel.BackgroundAccurate assessment of intermediate LMCA disease is critical for guiding decisions regarding revascularization. In theory, FFR across an intermediate LMCA stenosis will be affected by downstream disease, even if the pressure wire is positioned in the nondiseased downstream vessel.MethodsAfter percutaneous coronary intervention of the LAD, LCx, or both, an intermediate LMCA stenosis was created with a deflated balloon catheter. FFR was measured in the LAD and LCx coronary arteries before and after creation of downstream stenosis by inflating an angioplasty balloon within the newly placed stent. The true FFR (FFR_true) of the LMCA, measured in the nondiseased downstream vessel in the absence of stenosis in the other vessel, was compared with the apparent FFR (FFR_app) measured in the presence of stenosis.ResultsIn 25 patients, 91 pairs of measurements were made, 71 with LAD stenosis and 20 with LCx stenosis. FFR_true of the LMCA was significantly lower than FFR_app (0.81 ± 0.08 vs. 0.83 ± 0.08, p < 0.001), although the numerical difference was small. This difference correlated with the severity of the downstream disease (r = 0.35, p < 0.001). In all cases in which FFR_app was >0.85, FFR_true was >0.80.ConclusionsIn most cases, downstream disease does not have a clinically significant impact on the assessment of FFR across an intermediate LMCA stenosis with the pressure wire positioned in the nondiseased vessel.     

Diagnostic Accuracy of Myocardial Magnetic Resonance Perfusion to Diagnose Ischemic Stenosis With Fractional Flow Reserve as Reference: Systematic Review and Meta-Analysis

ObjectivesThis paper systematically analyzed the performance of magnetic resonance (MR) perfusion to diagnose coronary artery disease (CAD) with fractional flow reserve (FFR) as the reference standard.BackgroundMyocardial MR perfusion has passed the stage of a research technique and has demonstrated the ability to detect functional or ischemic stenosis of coronary arteries. However, the evidence is limited to single-center studies and small sample sizes.MethodsWe searched PubMed and Embase databases for all published studies that evaluated the accuracy of MR perfusion to diagnose CAD versus FFR. We used an exact binomial rendition of the bivariate mixed-effects regression model with test type as a random-effects covariate to synthesize the available data. Based on Bayes’ theorem, the post-test probability was calculated to guide MR perfusion’s clinical utility.ResultsWe identified 14 studies evaluating 1,073 arteries and 650 patients. The pooled sensitivity and specificity were 0.90 (95% confidence interval [CI]: 0.86 to 0.93) and 0.87 (95% CI: 0.82 to 0.90) at the patient level and 0.89 (95% CI: 0.83 to 0.92) and 0.86 (95% CI: 0.77 to 0.92) at the artery and territory levels, respectively. The area under the summary receiver-operating characteristic at the patient level was 0.95 (95% CI: 0.92 to 0.96) and 0.93 (95% CI: 0.91 to 0.95) at the artery and territory levels, respectively. MR perfusion could increase the post-test probability of CAD >80% in patients with a pre-test probability of >37% and can decrease post-test probability of CAD <20% with a pre-test probability of <72%.ConclusionsWith FFR as the reference standard, the diagnostic ability of MR perfusion to detect ischemic CAD is high.     

Intravascular Ultrasound-Derived Minimal Lumen Area Criteria for Functionally Significant Left Main Coronary Artery Stenosis

ObjectivesThis study sought to evaluate the intravascular ultrasound (IVUS) minimal lumen area (MLA) for functionally significant left main coronary artery (LMCA) stenosis using fractional flow reserve (FFR) as the standard.BackgroundThe evaluation of significant LMCA stenosis remains challenging.MethodsWe identified 112 patients with isolated ostial and shaft intermediate LMCA stenosis (angiographic diameter stenosis of 30% to 80%) who underwent IVUS and FFR measurement.ResultsThe FFR was ≤0.80 in 66 LMCA lesions (59%); these exhibited smaller reference vessels, smaller minimal lumen diameter, greater diameter of stenosis, longer lesion length, smaller MLA, larger plaque burden, and more frequent plaque rupture. The independent factors of an FFR of ≤0.80 were plaque rupture (odds ratio [OR]: 4.47; 95% Confidence Interval (CI): 1.35 to 14.8; p = 0.014); body mass index (OR: 1.19; 95% CI: 1.00 to 1.41; p = 0.05), age (OR: 0.95; 95% CI: 0.90 to 1.00; p = 0.031), and IVUS MLA (OR: 0.37; 95% CI: 0.25 to 0.56; p < 0.001). The optimal IVUS MLA cutoff value for an FFR of ≤0.80 was 4.5 mm² (77% sensitivity, 82% specificity, 84% positive predictive value, 75% negative predictive value, area under the curve: 0.83, 95% CI: 0.76 to 0.96; p < 0.001) overall and 4.1 to 4.5 mm² in various subgroups. Adjustment for the body surface area, body mass index, and left ventricular mass did not improve the diagnostic accuracy of the IVUS MLA.ConclusionsIn patients with isolated ostial and shaft intermediate LMCA stenosis, an IVUS-derived MLA of ≤4.5 mm² is a useful index of an FFR of ≤0.80.     

Fractional Flow Reserve and Coronary Bifurcation Anatomy: A Novel Quantitative Model to Assess and Report the Stenosis Severity of Bifurcation Lesions

ObjectivesThe aim of this study was to develop a new model for assessment of stenosis severity in a bifurcation lesion including its core. The diagnostic performance of this model, powered by 3-dimensional quantitative coronary angiography to predict the functional significance of obstructive bifurcation stenoses, was evaluated using fractional flow reserve (FFR) as the reference standard.BackgroundDevelopment of advanced quantitative models might help to establish a relationship between bifurcation anatomy and FFR.MethodsPatients who had undergone coronary angiography and interventions in 5 European cardiology centers were randomly selected and analyzed. Different bifurcation fractal laws, including Murray, Finet, and HK laws, were implemented in the bifurcation model, resulting in different degrees of stenosis severity.ResultsA total of 78 bifurcation lesions in 73 patients were analyzed. In 51 (65%) bifurcations, FFR was measured in the main vessel. A total of 34 (43.6%) interrogated vessels had an FFR ≤0.80. Correlation between FFR and diameter stenosis was poor by conventional straight analysis (ρ = −0.23, p < 0.001) but significantly improved by bifurcation analyses: the highest by the HK law (ρ = −0.50, p < 0.001), followed by the Finet law (ρ = −0.49, p < 0.001), and the Murray law (ρ = −0.41, p < 0.001). The area under the receiver-operating characteristics curve for predicting FFR ≤0.80 was significantly higher by bifurcation analysis compared with straight analysis: 0.72 (95% confidence interval: 0.61 to 0.82) versus 0.60 (95% confidence interval: 0.49 to 0.71; p = 0.001). Applying a threshold of ≥50% diameter stenosis, as assessed by the bifurcation model, to predict FFR ≤0.80 resulted in 23 true positives, 27 true negatives, 17 false positives, and 11 false negatives.ConclusionsThe new bifurcation model provides a comprehensive assessment of bifurcation anatomy. Compared with straight analysis, identification of lesions with preserved FFR values in obstructive bifurcation stenoses was improved. Nevertheless, accuracy was limited by using solely anatomical parameters.     

Prospective Assessment of the Diagnostic Accuracy of Instantaneous Wave-Free Ratio to Assess Coronary Stenosis Relevance: Results of ADVISE II International,Multicenter Study (ADenosine Vasodilator Independent Stenosis Evaluation II)

ObjectivesThe purpose of this study was to assess the diagnostic accuracy of the instantaneous wave-free ratio (iFR) to characterize, outside of a pre-specified range of values, stenosis severity, as defined by fractional flow reserve (FFR) ≤0.80, in a prospective, independent, controlled, core laboratory–based environment.BackgroundStudies with methodological heterogeneity have reported some discrepancies in the classification agreement between iFR and FFR. The ADVISE II (ADenosine Vasodilator Independent Stenosis Evaluation II) study was designed to overcome limitations of previous iFR versus FFR comparisons.MethodsA total of 919 intermediate coronary stenoses were investigated during baseline and hyperemia. From these, 690 pressure recordings (n = 598 patients) met core laboratory physiology criteria and are included in this report.ResultsThe pre-specified iFR cut-off of 0.89 was optimal for the study and correctly classified 82.5% of the stenoses, with a sensitivity of 73.0% and specificity of 87.8% (C statistic: 0.90 [95% confidence interval (CI): 0.88 to 0.92, p < 0.001]). The proportion of stenoses properly classified by iFR outside of the pre-specified treatment (≤0.85) and deferral (≥0.94) values was 91.6% (95% CI: 88.8% to 93.9%). When combined with FFR use within these cut-offs, the percent of stenoses properly classified by such a pre-specified hybrid iFR-FFR approach was 94.2% (95% CI: 92.2% to 95.8%). The hybrid iFR-FFR approach obviated vasodilators from 65.1% (95% CI: 61.1% to 68.9%) of patients and 69.1% (95% CI: 65.5% to 72.6%) of stenoses.ConclusionsThe ADVISE II study supports, on the basis rigorous methodology, the diagnostic value of iFR in establishing the functional significance of coronary stenoses, and highlights its complementariness with FFR when used in a hybrid iFR-FFR approach. (ADenosine Vasodilator Independent Stenosis Evaluation II–ADVISE II; NCT01740895)     

Prognostic Value of Fractional Flow Reserve: Linking Physiologic Severity to Clinical Outcomes

BackgroundFractional flow reserve (FFR) has become an established tool for guiding treatment, but its graded relationship to clinical outcomes as modulated by medical therapy versus revascularization remains unclear.ObjectivesThe study hypothesized that FFR displays a continuous relationship between its numeric value and prognosis, such that lower FFR values confer a higher risk and therefore receive larger absolute benefits from revascularization.MethodsMeta-analysis of study- and patient-level data investigated prognosis after FFR measurement. An interaction term between FFR and revascularization status allowed for an outcomes-based threshold.ResultsA total of 9,173 (study-level) and 6,961 (patient-level) lesions were included with a median follow-up of 16 and 14 months, respectively. Clinical events increased as FFR decreased, and revascularization showed larger net benefit for lower baseline FFR values. Outcomes-derived FFR thresholds generally occurred around the range 0.75 to 0.80, although limited due to confounding by indication. FFR measured immediately after stenting also showed an inverse relationship with prognosis (hazard ratio: 0.86, 95% confidence interval: 0.80 to 0.93; p < 0.001). An FFR-assisted strategy led to revascularization roughly half as often as an anatomy-based strategy, but with 20% fewer adverse events and 10% better angina relief.ConclusionsFFR demonstrates a continuous and independent relationship with subsequent outcomes, modulated by medical therapy versus revascularization. Lesions with lower FFR values receive larger absolute benefits from revascularization. Measurement of FFR immediately after stenting also shows an inverse gradient of risk, likely from residual diffuse disease. An FFR-guided revascularization strategy significantly reduces events and increases freedom from angina with fewer procedures than an anatomy-based strategy.     

Impact of Glycoprotein IIb/IIIa Inhibition in Contemporary Percutaneous Coronary Intervention for Acute Coronary Syndromes: Insights From the National Cardiovascular Data Registry

ObjectivesThis study investigates the effects of glycoprotein IIb/IIIa inhibitors (GPIs) on outcomes after percutaneous coronary intervention (PCI).BackgroundIschemic complications are reduced after PCI when a GPI is added to heparin. However, there are limited data on the safety and efficacy in contemporary PCI.MethodsWe used the National Cardiovascular Data Registry CathPCI Registry data to assess the association between GPI use and PCI outcomes for acute coronary syndrome between July 2009 and September 2011. The primary outcome was all-cause in-hospital mortality. The secondary outcome was major bleeding. To adjust for potential bias, we used multivariable logistic regression, propensity-matched (PM) analysis, and instrumental variable analysis (IVA).ResultsThere were 970,865 patients included; 326,283 (33.6%) received a GPI. Unadjusted mortality and major bleeding were more common with a GPI (2.4% vs. 1.4% and 3.7% vs. 1.5%, respectively; p < 0.001 for both). In contrast, GPI use was associated with lower mortality on adjusted analyses; relative risks range from 0.72 (95% confidence interval [CI]: 0.50 to 0.97) with IVA to 0.90 (95% CI: 0.86 to 0.95) with PM. The association of GPI use with bleeding remained in adjusted analyses (multivariable relative risk: 1.93, 95% CI: 1.83 to 2.04; PM relative risk: 1.83, 95% CI: 1.74 to 1.92; and IVA relative risk: 1.53, 95% CI: 1.27 to 2.13). Subgroup analysis revealed enhanced risk reduction with ST-segment elevation myocardial infarction, high predicted mortality, and heparin-based anticoagulation.ConclusionsIn unselected acute coronary syndrome patients undergoing PCI, GPI use was associated with reduced in-hospital mortality and increased bleeding. In the modern era of PCI, there may still be a role for the judicious use of GPIs.     

Local Low Shear Stress and Endothelial Dysfunction in Patients With Nonobstructive Coronary Atherosclerosis

BackgroundLocal hemodynamic factors are important determinants of atherosclerotic plaque development and progression.ObjectivesThe goal of this study was to determine the association between low endothelial shear stress (ESS) and microvascular and epicardial endothelial dysfunction in patients with early atherosclerosis.MethodsSixty-five patients (mean age 52 ± 11 years) with nonobstructive coronary atherosclerosis (luminal diameter stenosis <30%) were included. Microvascular and epicardial coronary endothelial function was assessed by using intracoronary acetylcholine infusion. Vascular profiling, using 2-plane coronary angiography and intravascular ultrasound, was used to reconstruct the three-dimensional anatomy of the left anterior descending artery. Each reconstructed artery was divided into sequential 3-mm segments and analyzed for local ESS with computational fluid dynamics; that is, lower ESS levels at both a 3-mm regional level (average ESS and low ESS) and at a vessel level (lowest ESS per artery) and for plaque characteristics (plaque area, plaque thickness, and plaque burden).ResultsCoronary segments in arteries with abnormal microvascular function exhibited lower ESS compared with segments in arteries with normal microvascular function (average ESS: 1.67 ± 1.04 Pa vs. 2.03 ± 1.72 Pa [p = 0.050]; lowest ESS: 0.54 ± 0.25 Pa vs. 0.72 ± 0.32 Pa [p = 0.014]). Coronary segments in arteries with abnormal epicardial endothelial function also exhibited significantly lower ESS compared with segments in arteries with normal epicardial function (average ESS: 1.49 ± 0.89 Pa vs. 1.93 ± 1.50 Pa [p < 0.0001]; low ESS: 1.26 ± 0.81 Pa vs. 1.56 ± 1.30 Pa [p = 0.001]; lowest ESS: 0.51 ± 0.27 Pa vs. 0.65 ± 0.29 Pa [p = 0.080]). Patients with abnormal microvascular endothelial function exhibited a progressive decrease in average and low ESS, starting from patients with normal epicardial endothelial function to those with both microvascular and epicardial endothelial dysfunction (p < 0.0001 and p = 0.004, respectively).ConclusionsThese data indicate an association between dysfunction of the microvascular and epicardial endothelium and local ESS at the early stages of coronary atherosclerosis in humans.     

Prevalence of Coronary Microvascular Dysfunction Among Patients With Chest Pain and Nonobstructive Coronary Artery Disease

ObjectivesThis study assessed the prevalence of coronary microvascular abnormalities in patients presenting with chest pain and nonobstructive coronary artery disease (CAD).BackgroundCoronary microvascular abnormalities mediate ischemia and can lead to an increased risk of cardiovascular events.MethodsUsing an intracoronary Doppler guidewire, endothelial-dependent microvascular function was examined by evaluating changes in coronary blood flow in response to acetylcholine, whereas endothelial-independent microvascular function was examined by evaluating changes in coronary flow velocity reserve in response to intracoronary adenosine. Patients were divided into 4 groups depending on whether they had a normal (+) or abnormal (−) coronary blood flow (CBF) in response to acetylcholine (Ach) and a normal (+) or abnormal (−) coronary flow velocity reserve (CFR) in response to adenosine (Adn): CBFAch+, CFRAdn+ (n = 520); CBFAch−, CFRAdn+ (n = 478); CBFAch+, CFRAdn− (n = 173); and CBFAch−, CFRAdn− (n = 268).ResultsTwo-thirds of all patients had some sort of microvascular dysfunction. Women were more prevalent in each group (56% to 82%). Diabetes was uncommon in all groups (7% to 12%), whereas hypertension and hyperlipidemia were relatively more prevalent in each group, although rates for most conventional cardiovascular risk factors did not differ significantly between groups. There were no significant differences in the findings of noninvasive functional testing between groups. In a multivariable analysis, age was the only variable that independently predicted abnormal microvascular function.ConclusionsPatients with chest pain and nonobstructive CAD have a high prevalence of coronary microvascular abnormalities. These abnormalities correlate poorly with conventional cardiovascular risk factors and are dissociated from the findings of noninvasive functional testing.     

Long-Term Survival Benefit of Revascularization Compared With Medical Therapy in Patients With Coronary Chronic Total Occlusion and Well-Developed Collateral Circulation

ObjectivesThe purpose of this study was to compare the long-term clinical outcomes of patients with chronic total occlusion (CTO) and well-developed collateral circulation treated with revascularization versus medical therapy.BackgroundLittle is known about the clinical outcomes and optimal treatment strategies of CTO with well-developed collateral circulation.MethodsWe screened 2,024 consecutive patients with at least 1 CTO detected on coronary angiogram. Of these, we analyzed data from 738 patients with Rentrop 3 grade collateral circulation who were treated with medical therapy alone (n = 236), coronary artery bypass grafting (n = 170) or percutaneous coronary intervention (n = 332; 80.1% successful). Patients who underwent revascularization and medical therapy (revascularization group, n = 502) were compared with those who underwent medical therapy alone (medication group, n = 236) in terms of cardiac death and major adverse cardiac events (MACE), defined as the composite of cardiac death, myocardial infarction, and repeat revascularization.ResultsDuring a median follow-up duration of 42 months, multivariate analysis revealed a significantly lower incidence of cardiac death (hazard ratio [HR]: 0.29; 95% confidence interval [CI]: 0.15 to 0.58; p < 0.01) and MACE (HR: 0.32; 95% CI: 0.21 to 0.49; p < 0.01) in the revascularization group compared with the medication group. After propensity score matching, the incidence of cardiac death (HR: 0.27; 95% CI: 0.09 to 0.80; p = 0.02) and MACE (HR: 0.44; 95% CI: 0.23 to 0.82; p = 0.01) were still significantly lower in the revascularization group than in the medication group.ConclusionsIn patients with coronary CTO and well-developed collateral circulation, aggressive revascularization may reduce the risk of cardiac mortality and MACE.     

Randomized Comparisons Between Different Stenting Approaches for Bifurcation Coronary Lesions With or Without Side Branch Stenosis

ObjectivesThis study sought to evaluate the optimal percutaneous coronary intervention techniques using drug-eluting stents for bifurcation coronary lesions.BackgroundThe optimal bifurcation stenting technique needs to be evaluated.MethodsThe trial included 2 randomization studies separated by the presence of side branch (SB) stenosis for patients having non–left main bifurcation lesions. For 306 patients without SB stenosis, the routine final kissing balloon or leave-alone approaches were compared. Another randomization study compared the crush or single-stent approaches for 419 patients with SB stenosis.ResultsBetween the routine final kissing balloon and leave-alone groups for nondiseased SB lesions, angiographic restenosis occurred in 17.9% versus 9.3% (p = 0.064), comprising 15.1% versus 3.7% for the main branch (p = 0.004) and 2.8% versus 5.6% for the SB (p = 0.50) from 214 patients (69.9%) receiving 8-month angiographic follow-up. Incidence of major adverse cardiac events including death, myocardial infarction, or target vessel revascularization over 1 year was 14.0% versus 11.6% between the routine final kissing balloon and leave-alone groups (p = 0.57). In another randomization study for diseased SB lesions, 28.2% in the single-stent group received SB stents. From 300 patients (71.6%) receiving angiographic follow-up, between the crush and single-stent groups, angiographic restenosis rate was 8.4% versus 11.0% (p = 0.44), comprising 5.2% versus 4.8% for the main branch (p = 0.90) and 3.9% versus 8.3% for the SB (p = 0.12). One-year major adverse cardiac events rate between the crush and single-stent groups was 17.9% versus 18.5% (p = 0.84).ConclusionsAngiographic and clinical outcomes were excellent after percutaneous coronary intervention using drug-eluting stents with any stent technique for non–left main bifurcation lesions once the procedure was performed successfully.     

Biochemical Validation of Patient-Reported Symptom Onset Time in Patients With ST-Segment Elevation Myocardial Infarction Undergoing Primary Percutaneous Coronary Intervention

ObjectivesThis study evaluated a biochemical validation of patient-reported symptom onset time in patients with ST-segment elevation myocardial infarction (STEMI).BackgroundSymptom onset time is an important metric but has never been formally validated.MethodsThe Mayo Clinic Percutaneous Coronary Intervention (PCI) Registry was interrogated to obtain baseline, procedural, and outcome data on 607 STEMI patients undergoing primary PCI. Biochemical onset time was determined by backward extrapolation of serial increasing cardiac troponin T (cTnT) measurements.ResultsThe median patient-reported onset time was 12 min later than the calculated time of first cTnT increase and was therefore estimated to be 4.2 h later than the biochemical onset time (interquartile range: 1.9 to 11.1 h; p < 0.001), assuming a 4-h interval between coronary occlusion and first cTnT increase. Conventional ischemic time showed no association with infarct size (correlation with peak cTnT: r = 0.023; p = 0.61) or 1-year mortality (hazard ratio: 0.97 per doubling; 95% confidence interval: 0.68 to 1.40; p = 0.88). However, after recalculation of ischemic time with biochemical onset time, significant associations with infarct size (r = 0.14; p = 0.001) and 1-year mortality (hazard ratio: 1.70 per doubling; 95% confidence interval: 1.20 to 2.40; p = 0.003) were found. When underestimation of ischemic time by patient-reported onset time increased, so did the risk of mortality.ConclusionsAlthough our point estimate should be interpreted with caution, our study indicates that the actual onset of STEMI is likely to be earlier than the patient-reported onset time. Recalculation of ischemic time with biochemical onset time greatly enhanced its prognostic value. Underestimation of ischemic time by patient-reported onset time occurred more often in high-risk patients.     

Outcomes of Inoperable Symptomatic Aortic Stenosis Patients Not Undergoing Aortic Valve Replacement: Insight Into the Impact of Balloon Aortic Valvuloplasty From the PARTNER Trial (Placement of AoRtic TraNscathetER Valve Trial)

ObjectivesThe aim of this report is to characterize the impact of balloon aortic valvuloplasty (BAV) in patients not undergoing aortic valve replacement in the PARTNER (Placement of AoRtic TraNscathetER Valves) trial.BackgroundThe PARTNER trial is the only randomized trial with independently adjudicated data of inoperable severe symptomatic aortic stenosis patients, allowing outcome analysis of unoperated-on patients.MethodsThe design and initial results of the PARTNER trial (Cohort B) were reported previously. After excluding patients with pre-randomization BAV, we compared patients undergoing BAV within 30 days of randomization (BAV group) with those not having BAV within 30 days of randomization (no BAV group) to characterize the use and impact of BAV.ResultsIn the PARTNER Cohort B study, 179 inoperable patients were randomized to standard treatment including 39 patients (21.8%) who had undergone a BAV before randomization (previous BAV group). Of the 140 patients who did not have BAV before enrollment in the study, 102 patients (73%) had BAV within 30 days of study randomization (BAV group). Survival at 3 months was greater in the BAV group compared with the no BAV group (88.2%; 95% confidence interval [CI]: 82.0% to 94.5% vs. 73.0%; 95% CI: 58.8% to 87.4%). However, survival was similar at 6-month follow-up (74.5%; 95% CI: 66.1% to 83.0% vs. 73.1%; 58.8% to 87.4%). There was improvement in quality of life parameters when paired comparisons were made between baseline and 30 days and 6 months between the BAV and no BAV groups, but this effect was lost at 12-month follow-up.ConclusionsBAV improves functional status and survival in the short term, but these benefits are not sustained. BAV for aortic stenosis patients who cannot undergo aortic valve replacement is a useful palliative therapy. (THE PARTNER TRIAL: Placement of AoRTic TraNscathetER Valve Trial; NCT00530894)     

Comparison of Stent Expansion Guided by Optical Coherence Tomography Versus Intravascular Ultrasound: The ILUMIEN II Study (Observational Study of Optical Coherence Tomography [OCT] in Patients Undergoing Fractional Flow Reserve [FFR] and Percutaneous Coronary Intervention)

ObjectivesThe present study sought to determine whether optical coherence tomography (OCT) guidance results in a degree of stent expansion comparable to that with intravascular ultrasound (IVUS) guidance.BackgroundThe most important predictor of adverse outcomes (thrombosis and restenosis) after stent implantation with IVUS guidance is the degree of stent expansion achieved.MethodsWe compared the relative degree of stent expansion (defined as the minimal stent area divided by the mean of the proximal and distal reference lumen areas) after OCT-guided stenting in patients in the ILUMIEN (Observational Study of Optical Coherence Tomography [OCT] in Patients Undergoing Fractional Flow Reserve [FFR] and Percutaneous Coronary Intervention) (N = 354) and IVUS-guided stenting in patients in the ADAPT-DES (Assessment of Dual Antiplatelet Therapy With Drug-Eluting Stents) study (N = 586). Stent expansion was examined in all 940 patients in a covariate-adjusted analysis as well as in 286 propensity-matched pairs (total N = 572).ResultsIn the matched-pair analysis, the degree of stent expansion was not significantly different between OCT and IVUS guidance (median [first, third quartiles] = 72.8% [63.3, 81.3] vs. 70.6% [62.3, 78.8], respectively, p = 0.29). Similarly, after adjustment for baseline differences in the entire population, the degree of stent expansion was also not different between the 2 imaging modalities (p = 0.84). Although a higher prevalence of post-PCI stent malapposition, tissue protrusion, and edge dissections was detected by OCT, the rates of major malapposition, tissue protrusion, and dissections were similar after OCT- and IVUS-guided stenting.ConclusionsIn the present post-hoc analysis of 2 prospective studies, OCT and IVUS guidance resulted in a comparable degree of stent expansion. Randomized trials are warranted to compare the outcomes of OCT- and IVUS-guided coronary stent implantation.