Five-Year Outcomes with PCI Guided by Fractional Flow Reserve

BACKGROUND

We hypothesized that fractional flow reserve (FFR)-guided percutaneous coronary intervention (PCI) would be superior to medical therapy as initial treatment in patients with stable coronary artery disease.

METHODS

Among 1220 patients with angiographically significant stenoses, those in whom at least one stenosis was hemodynamically significant (FFR, ≤0.80) were randomly assigned to FFR-guided PCI plus medical therapy or to medical therapy alone. Patients in whom all stenoses had an FFR of more than 0.80 received medical therapy and were entered into a registry. The primary end point was a composite of death, myocardial infarction, or urgent revascularization.

RESULTS

A total of 888 patients underwent randomization (447 patients in the PCI group and 441 in the medical-therapy group). At 5 years, the rate of the primary end point was lower in the PCI group than in the medical-therapy group (13.9% vs. 27.0%; hazard ratio, 0.46; 95% confidence interval [CI], 0.34 to 0.63; P<0.001). The difference was driven by urgent revascularizations, which occurred in 6.3% of the patients in the PCI group as compared with 21.1% of those in the medical-therapy group (hazard ratio, 0.27; 95% CI, 0.18 to 0.41). There were no significant differences between the PCI group and the medical-therapy group in the rates of death (5.1% and 5.2%, respectively; hazard ratio, 0.98; 95% CI, 0.55 to 1.75) or myocardial infarction (8.1% and 12.0%; hazard ratio, 0.66; 95% CI, 0.43 to 1.00). There was no significant difference in the rate of the primary end point between the PCI group and the registry cohort (13.9% and 15.7%, respectively; hazard ratio, 0.88; 95% CI, 0.55 to 1.39). Relief from angina was more pronounced after PCI than after medical therapy.

CONCLUSIONS

In patients with stable coronary artery disease, an initial FFR-guided PCI strategy was associated with a significantly lower rate of the primary composite end point of death, myocardial infarction, or urgent revascularization at 5 years than medical therapy alone. Patients without hemodynamically significant stenoses had a favorable long-term outcome with medical therapy alone. (Funded by St. Jude Medical and others; FAME 2 ClinicalTrials.gov number, NCT01132495 .).

Fractional flow reserve to guide and to assess coronary artery bypass grafting

The aim of this review is to highlight the role of invasive functional evaluation in patients in whom coronary artery bypass graft (CABG) is indicated, and to examine the clinical evidence available in favour of fractional flow reserve (FFR) adoption in these patients, outline appropriate use, as well as point out potential pitfalls. FFR after CABG will also be reviewed, highlighting its correct interpretation and adoption when applied to both native coronary arteries and bypass grafts. Practice European guidelines support the use of FFR to complement coronary angiography with the highest degree of recommendation (Class IA) for the assessment of coronary stenosis before undertaking myocardial revascularization when previous non-invasive functional evaluation is unavailable or not conclusive. As a result, FFR has been adopted in routine clinical practice to guide clinicians decision as to whether or not perform a revascularization. Of note, due to the increasing confidence of the interventional cardiologists, FFR guidance is also being implemented to indicate or guide CABG. This is in anticipation of supportive clear-cut evidence, since recommendations for FFR adoption were based on randomized clinical trials investigating percutaneous coronary intervention (PCI) strategies in which patients with typical indications for CABG were excluded (e.g. left main disease, valvular disease, and coronary anatomy unsuitable for PCI). Based on the critical appraisal of the literature, FFR can play an important role in risk stratification and determining management strategy of patients either before or after CABG.

Sniff of coke breaks the heart: cocaine-induced coronary vasospasm aggravated by therapeutic hypothermia and vasopressors after aborted sudden cardiac death: a case report

Introduction

Coronary vasospasm and sudden cardiac death are a frequently reported complication of cocaine abuse. We present a case with uniquely severe clinical and angiographic presentation.

Case presentation

A 39-year-old patient was presented to the cath lab after out-of-hospital cardiac arrest. Coronary angiography revealed focal coronary vasospasm in the proximal LCx, well responsive for intracoronary nitrates. Accordingly, no coronary intervention was performed and the patient was transferred to the cardiac intensive care unit. There, after systematically cooling sudden haemodynamic deterioration and massive ST-elevation was observed. Repeated coronary angiography revealed subocclusive LAD and LCx vasospasm, which again recovered after intracoronary injection of nitric oxide.

Discussion

Coronary-spastic effect of cocaine and its potentially dreadful clinical consequences are well-described phenomena. As novelty this case emphasizes that standard of care, including systematic hypothermia and vasopressor administration after out-of-hospital cardiac arrest can potentiate cocaine-induced coronary spasm with dramatic outcomes.

Reversed single string technique for coronary bifurcation stenting-First report of case demonstrations in vitro

OBJECTIVES

This work reports the concept and the practical feasibility of Reversed Single String bifurcation stenting technique by demonstrating three in vitro cases.

BACKGROUND

Provisional T stenting is the most used interventional technique to treat coronary bifurcation lesions. However, after main branch (MB) stenting, treatment of the side branch (SB) may become indicated to provide a good final result. Currently applied methods all have their structural limitations with respect to wall coverage, multiple strut layers, poor apposition rate. We reasoned that reversing the Single String technique principle could be used as a bail out after inadequate provisional T stenting.

METHODS AND RESULTS

We simulated in three silicone bifurcation phantoms a scenario whereby stenting the SB becomes indicated after provisional T stenting. Thereafter, as first step of Reversed Single String, a stent was deployed into the SB ostium with one single protruding stent-cell into the MB. After wiring that stent-cell and positioning MB balloon across it, final kissing balloon dilation was performed. Results of the in vitro Reversed Single String cases were evaluated by X-ray angiography, optical frequency domain imaging, and 3-Dimensional (3D) reconstruction (OFDI). Each case was successfully performed and completed. In the bifurcation area, perfect apposition was documented in over 81% of the struts. Malapposition remained below 4% of struts in each case. 3D OFDI reconstruction did not reveal any strut fracture.

CONCLUSION

This report suggests that Reversed Single String technique might offer a potential bail out solution for provisional T-stenting cases, when treatment of the SB becomes indicated. © 2017 Wiley Periodicals, Inc.

Can Functional Testing for Ischemia and Viability Guide Revascularization?

Cardiac imaging procedures are a cornerstone of the diagnosis and management of patients with cardiac disease. The optimal management of the patient with stable ischemic heart disease or ischemic heart failure often rests on the totality of symptom burden, patient risk, and disease severity, whether assessed anatomically or functionally. Recent trials have demonstrated the power of flow measurements to direct revascularization as well as the strengths and limitations of ischemia and viability/hibernation imaging as markers of risk to direct interventions. They have also highlighted the challenges in evaluating imaging or functional testing to direct therapies, because imaging does not directly affect outcome itself, rather it affects the management decisions that may result in a positive outcome. Ongoing studies with randomized designs, such as FAME 3 (Fractional Flow Reserve versus Angiography for Multivessel Evaluation), ISCHEMIA (International Study of Comparative Health Effectiveness with Medical and Invasive Approaches), and AIMI-HF (Alternative Imaging Modalities in Ischemic Heart Failure) (IMAGE-HF [Imaging Modalities to Assist with Guiding Therapy in The Evaluation of Patients with Heart Failure]), will provide the highest level of evidence to support practice changes that may further clarify the role of cardiac imaging in the evaluation of these patients and result in improved patient outcomes.

Standardization of Fractional Flow Reserve Measurements

Pressure wire-based fractional flow reserve is considered the standard of reference for evaluation of the ischemic potential of coronary stenoses and the expected benefit from revascularization. Accordingly, its application in daily practice or for research purposes has to be as standardized as possible to avoid technical or operator-related artifacts in pressure recordings. This document proposes a standardized way of acquiring, recording, interpreting, and archiving the pressure tracings for daily practice and for the purpose of clinical research involving a core laboratory. Proposed standardized steps enhance the uniformity of clinical practices and data interpretation.

Intracoronary Adenosine: Dose-Response Relationship With Hyperemia

OBJECTIVES

The present study sought to establish the dosage of intracoronary (IC) adenosine associated with minimal side effects and above which no further increase in flow can be expected.

BACKGROUND

Despite the widespread adoption of IC adenosine in clinical practice, no wide-ranging, dose-response study has been conducted. A recurring debate still exists regarding its optimal dose.

METHODS

In 30 patients, Doppler-derived flow velocity measurements were obtained in 10 right coronary arteries (RCAs) and 20 left coronary arteries (LCAs) free of stenoses >20% in diameter. Flow velocity was measured at baseline and after 8 ml bolus administrations of arterial blood, saline, contrast medium, and 9 escalating doses of adenosine (4 to 500 μg). The hyperemic value was expressed in percent of the maximum flow velocity reached in a given artery (Q/Qmax, %).

RESULTS

Q/Qmax did not increase significantly beyond dosages of 60 μg for the RCA and 160 μg for LCA. Heart rate did not change, whereas mean arterial blood pressure decreased by a maximum of 7% (p < 0.05) after bolus injections of IC adenosine. The incidence of transient A-V blocks was 40% after injection of 100 μg in the RCA and was 15% after injection of 200 μg in the LCA. The duration of the plateau reached 12 ± 13 s after injection of 100 μg in the RCA and 21 ± 6 s after the injection of 200 μg in the LCA. A progressive prolongation of the time needed to return to baseline was observed. Hyperemic response after injection of 8 ml of contrast medium reached 65 ± 36% of that achieved after injection of 200 μg of adenosine.

CONCLUSIONS

This wide-ranging, dose-response study indicates that an IC adenosine bolus injection of 100 μg in the RCA and 200 μg in the LCA induces maximum hyperemia while being associated with minimal side effects.

Fractional Flow Reserve-Guided Revascularization in Patients With Aortic Stenosis

Fractional flow reserve (FFR) has never been investigated in patients with aortic stenosis (AS). From 2002 to 2010, we identified 106 patients with AS and coronary artery disease with at least one intermediate lesion treated according to FFR guidance. We matched 212 contemporary control patients with AS in which revascularization was decided on angiography only. More patients in the FFR-guided group underwent percutaneous coronary intervention (24% vs 13%; p = 0.019), whereas there was a trend toward less coronary artery bypass grafting (CABG) performed. After FFR, the number of diseased vessels was downgraded within the FFR-guided group (from 1.85 ± 0.97 to 1.48 ± 1; p <0.01) and compared with the angio-guided group (1.48 ± 1 vs 1.8 ± 0.97; p <0.01). Less aortic valve replacement was reported in the FFR-guided group (46% vs 57%; p = 0.056). In patients who underwent CABG, less venous conduits (0.5 ± 0.69 vs 0.73 ± 0.76; p = 0.05) and anastomoses (0.61 ± 0.85 vs 0.94 ± 1; p = 0.032) were necessary in the FFR-guided group. Up to 5 years, we found no difference in major adverse cardiac events (38% vs 39%; p = 0.98), overall death (32% vs 31%; p = 0.68), nonfatal myocardial infarction (2% vs 2%; p = 0.79), and revascularization (8% vs 7%; p = 0.76) between the 2 groups. In conclusion, FFR guidance impacts the management of selected patients with moderate or severe AS and coronary artery disease by resulting into deferral of aortic valve replacement, more patients treated with percutaneous coronary intervention, and in patients treated with CABG, into less venous grafts and anastomoses without increasing adverse event rates up to 5 years.

The impact of downstream coronary stenosis on fractional flow reserve assessment of intermediate left main coronary artery disease: human validation

OBJECTIVES

The 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.

BACKGROUND

Accurate 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.

METHODS

After 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 (FFRtrue) of the LMCA, measured in the nondiseased downstream vessel in the absence of stenosis in the other vessel, was compared with the apparent FFR (FFRapp) measured in the presence of stenosis.

RESULTS

In 25 patients, 91 pairs of measurements were made, 71 with LAD stenosis and 20 with LCx stenosis. FFRtrue of the LMCA was significantly lower than FFRapp (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 FFRapp was >0.85, FFRtrue was >0.80.

CONCLUSIONS

In 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.

Single String Technique for Coronary Bifurcation Stenting: Detailed Technical Evaluation and Feasibility Analysis

OBJECTIVES

The study aimed to evaluate the adequacy and feasibility of the single string bifurcation stenting technique.

BACKGROUND

Double-stent techniques may be required for complex bifurcations. Currently applied methods all have their morphological or structural limitations with respect to wall coverage, multiple strut layers, and apposition rate.

METHODS

Single string is a novel method in which, first, the side branch (SB) stent is deployed with a single stent cell protruding into the main branch (MB). Second, the MB stent is deployed across this protruding stent cell. The procedure is completed by final kissing balloon dilation. The single string technique was first tested in vitro (n = 20) and next applied in patients (n = 11) with complex bifurcation stenoses.

RESULTS

All procedures were performed successfully, crossing a single stent cell in 100%. Procedure duration was 23.0 ± 7.9 min, and the fluoroscopy time was 9.4 ± 3.5 min. The results were evaluated by optical coherence tomography, showing fully apposed struts in 83.0 ± 9.2% in the bifurcation area. Residual area obstruction in the MB was 6.4 ± 5.6% and 25.0 ± 16.9% in the SB, as evaluated by micro computed tomography. All the human cases were performed successfully with excellent angiographic results: the residual area stenosis was 27 ± 8% and 29 ± 10% in the MB and in the SB, respectively, by 3-dimensional quantitative coronary angiography. No relevant periprocedural enzyme increase was observed. During follow-up (6 ± 4 months), no adverse clinical events (death, myocardial infarction, target vessel revascularization) were noted.

CONCLUSIONS

The single string technique for complex bifurcation dilation was shown to be adequate in vitro and feasible in humans, with favorable results in terms of stent overlap, malapposition rate, and low residual obstruction in both the MB and SB.

Revascularization Decisions in Patients With Stable Angina and Intermediate Lesions

Background—

Fractional flow reserve (FFR) measurement of intermediate coronary stenoses is recommended by guidelines when demonstration of ischemia by noninvasive testing is unavailable. The study aims to evaluate the penetration of this recommendation into current thinking about revascularization strategies for stable coronary artery disease.

Methods and Results—

International Survey on Interventional Strategy was conducted via a web-based platform. First, participants’ experiences in interventional cardiology were queried. Second, 5 complete angiograms were provided, presenting only focal intermediate stenoses. FFR and quantitative coronary angiography values were known; however, remained undisclosed. Determination of stenosis significance was asked for each lesion. In cases of uncertainty, the most appropriate adjunctive invasive diagnostic method among quantitative coronary angiography, intravascular ultrasound, optical coherence tomography, or FFR needed to be selected. International Survey on Interventional Strategy was taken by 495 participants who provided 4421 lesion evaluations. In 3158 (71%) decisions, participants relied solely on angiographic appearance that was discordant in 47% with the known FFR, using 0.80 as cutoff value. The use of FFR and imaging modalities was requested in 21% and 8%, respectively. Comparing 4 groups of participants according to the experience in FFR, angiogram-based decisions were less frequent with increasing experience (77% versus 72% versus 69% versus 67%, respectively; P <0.001). As a result, requests for FFR were more frequent (14% versus 19% versus 24% versus 28%, respectively; P <0.001) and rates of discordant decisions decreased (51% versus 49% versus 47% versus 43%, respectively; P <0.022).

Conclusions—

The findings confirm that, even when all potential external constraints are virtually eliminated, visual estimation continues to dominate the treatment decisions for intermediate stenoses, indicative of a worrisome disconnect between recommendations and current practice.