Clinical Outcome of Revascularization Deferral With Instantaneous Wave-Free Ratio and Fractional Flow Reserve: A 5-Year Follow-Up Substudy From the iFR-SWEDEHEART Trial.

Background Although physiology-based assessment of coronary artery stenosis using instantaneous wave-free ratio (iFR) and fractional flow reserve (FFR) are established methods of guiding coronary revascularization, its clinical outcome in long-term deferral needs further evaluation, especially with acute coronary syndrome as a clinical presentation. The aim was to evaluate the long-term clinical outcome of deferral of revascularization based on iFR or FFR. Methods and Results This is a substudy of the iFR-SWEDEHEART (Instantaneous Wave-Free Ratio Versus Fractional Flow Reserve in Patients With Stable Angina Pectoris or Acute Coronary Syndrome) randomized clinical trial, where patients deferred from revascularization from each study arm were selected. Nine hundred eight patients deferred from coronary revascularization with iFR (n=473) and FFR (n=435) were followed for 5 years. The national quality registry, SWEDEHEART (Swedish Web-System for Enhancement and Development of Evidence-Based Care in Heart Disease Evaluated According to Recommended Therapies), was used for patient data collection and clinical follow-up. The end point was major adverse cardiac events and their individual components all-cause death, cardiovascular death, noncardiovascular death, nonfatal myocardial infarction, and unplanned revascularization. No significant difference was found in major adverse cardiac events (iFR 18.6% versus FFR 16.8%; adjusted hazard ratio, 1.08 [95% CI, 0.79-1.48]; P=0.63) or their individual components. Conclusions No differences in clinical outcomes after 5-year follow-up were noted when comparing iFR versus FFR as methods for deferral of coronary revascularization in patients presenting with stable angina pectoris and acute coronary syndrome. Registration URL: https://www.clinicaltrials.gov; Unique identifier: NCT02166736.

5-Year Outcomes of PCI Guided by Measurement of Instantaneous Wave-Free Ratio Versus Fractional Flow Reserve.

BACKGROUND: Instantaneous wave-free ratio (iFR) is a coronary physiology index used to assess the severity of coronary artery stenosis to guide revascularization. iFR has previously demonstrated noninferior short-term outcome compared to fractional flow reserve (FFR), but data on longer-term outcome have been lacking. OBJECTIVES: The purpose of this study was to investigate the prespecified 5-year follow-up of the primary composite outcome of all-cause mortality, myocardial infarction, and unplanned revascularization of the iFR-SWEDEHEART trial comparing iFR vs FFR in patients with chronic and acute coronary syndromes. METHODS: iFR-SWEDEHEART was a multicenter, controlled, open-label, registry-based randomized clinical trial using the Swedish Coronary Angiography and Angioplasty Registry for enrollment. A total of 2,037 patients were randomized to undergo revascularization guided by iFR or FFR. RESULTS: No patients were lost to follow-up. At 5 years, the rate of the primary composite endpoint was 21.5% in the iFR group and 19.9% in the FFR group (HR: 1.09; 95% CI: 0.90-1.33). The rates of all-cause death (9.4% vs 7.9%; HR: 1.20; 95% CI: 0.89-1.62), nonfatal myocardial infarction (5.7% vs 5.8%; HR: 1.00; 95% CI: 0.70-1.44), and unplanned revascularization (11.6% vs 11.3%; HR: 1.02; 95% CI: 0.79-1.32) were also not different between the 2 groups. The outcomes were consistent across prespecified subgroups. CONCLUSIONS: In patients with chronic or acute coronary syndromes, an iFR-guided revascularization strategy was associated with no difference in the 5-year composite outcome of death, myocardial infarction, and unplanned revascularization compared with an FFR-guided revascularization strategy. (Evaluation of iFR vs FFR in Stable Angina or Acute Coronary Syndrome [iFR SWEDEHEART]; NCT02166736).

Instantaneous wave-free ratio compared with fractional flow reserve in PCI: A cost-minimization analysis.

BACKGROUND: Coronary physiology is a routine diagnostic tool when assessing whether coronary revascularization is indicated. The iFR-SWEDEHEART trial demonstrated similar clinical outcomes when using instantaneous wave-free ratio (iFR) or fractional flow reserve (FFR) to guide revascularization. The objective of this analysis was to assess a cost-minimization analysis of iFR-guided compared with FFR-guided revascularization. METHODS: In this cost-minimization analysis we used a decision-tree model from a healthcare perspective with a time-horizon of one year to estimate the cost difference between iFR and FFR in a Nordic setting and a United States (US) setting. Treatment pathways and health care utilizations were constructed from the iFR-SWEDEHEART trial. Unit cost for revascularization and myocardial infarction in the Nordic setting and US setting were derived from the Nordic diagnosis-related group versus Medicare cost data. Unit cost of intravenous adenosine administration and cost per stent placed were based on the average costs from the enrolled centers in the iFR-SWEDEHEART trial. Deterministic and probabilistic sensitivity analyses were carried out to test the robustness of the result. RESULTS: The cost-minimization analysis demonstrated a cost saving per patient of $681 (95% CI: $641 - $723) in the Nordic setting and $1024 (95% CI: $934 - $1114) in the US setting, when using iFR-guided compared with FFR-guided revascularization. The results were not sensitive to changes in uncertain parameters or assumptions. CONCLUSIONS: IFR-guided revascularization is associated with significant savings in cost compared with FFR-guided revascularization.

Single-center evaluation of a next generation fully repositionable and retrievable transcatheter aortic valve replacement.

BACKGROUND: The mechanically expandable Lotus Valve System is a fully repositionable and retrievable valve with an adaptive seal to minimize paravalvular leak (PVL). The aim of this study was to evaluate the short- and long-term safety and efficacy of the new device with focus on a new implantation technique to reduce the need for a permanent pacemaker (PPM) post procedure. METHODS: We performed a prospective single-center, non-randomized evaluation of the Lotus Valve System. The first 100 consecutive Lotus Valve implantations were included in the analysis. Outcome was assessed according to VARC2-criteria. Postoperative pacemaker rates were assessed using the national pacemaker registry and electronic medical records. Mortality at 30 days and 12 months were acquired from the national population registry. RESULTS: Mean age was 82.7 ± 5.6 years, mean Euroscore I was 25.3 ± 14.5%, mean STS-score was 6.5 ± 4.1% and mean aortic valve area was 0.6 ± 0.1 cm2. There were no cases of valve embolization, ectopic valve deployment or additional valve implantation. Device success according to the VARC2-criteria was 97%. The 30-day mortality rate was 3%. Two deaths occurred due to stroke and one due to a ventricular rupture. Major stroke rate was 2% and major vascular complication rate was 2%. The 12-month mortality rate was 14%. At discharge 87% of patients had no/trace PVL, 12% had mild PVL and one patient had a moderate PVL. A total of 13% received a new PPM post valve implantation. Among patients who did not have a PPM before the procedure, the PPM rate was 15.3%. CONCLUSIONS: This single-center evaluation of the Lotus Valve System demonstrated a good clinical outcome with a low mortality, in a high-risk population. Introduction of a new implantation technique resulted in lower PPM rates than previously reported without negatively affecting PVL. TRIAL REGISTRATION: Current Controlled Trials ISRCTN14952278 , retrospectively registered 06/11/2017.

Reclassification of Treatment Strategy With Instantaneous Wave-Free Ratio and Fractional Flow Reserve: A Substudy From the iFR-SWEDEHEART Trial.

OBJECTIVES: The authors sought to compare reclassification of treatment strategy following instantaneous wave-free ratio (iFR) and fractional flow reserve (FFR). BACKGROUND: iFR was noninferior to FFR in 2 large randomized controlled trials in guiding coronary revascularization. Reclassification of treatment strategy by FFR is well-studied, but similar reports on iFR are lacking. METHODS: The iFR-SWEDEHEART (Instantaneous Wave-Free Ratio Versus Fractional Flow Reserve in Patients With Stable Angina Pectoris or Acute Coronary Syndrome Trial) study randomized 2,037 participants with stable angina or acute coronary syndrome to treatment guided by iFR or FFR. Interventionalists entered the preferred treatment (optimal medical therapy [OMT], percutaneous coronary intervention [PCI], or coronary artery bypass grafting [CABG]) on the basis of coronary angiograms, and the final treatment decision was mandated by the iFR/FFR measurements. RESULTS: In the iFR/FFR (n = 1,009/n = 1,004) populations, angiogram-based treatment approaches were similar (p = 0.50) with respect to OMT (38%/35%), PCI of 1 (37%/39%), 2 (15%/16%), and 3 vessels (2%/2%) and CABG (8%/8%). iFR and FFR reclassified 40% and 41% of patients, respectively (p = 0.78). The majority of reclassifications were conversion of PCI to OMT in both the iFR/FFR groups (31.4%/29.0%). Reclassification increased with increasing number of lesions evaluated (odds ratio per evaluated lesion for FFR: 1.46 [95% confidence interval: 1.22 to 1.76] vs. iFR 1.37 [95% confidence interval: 1.18 to 1.59]). Reclassification rates for patients with 1, 2, and 3 assessed vessels were 36%, 52%, and 53% (p < 0.01). CONCLUSIONS: Reclassification of treatment strategy of intermediate lesions was common and occurred in 40% of patients with iFR or FFR. The most frequent reclassification was conversion from PCI to OMT regardless of physiology modality. Irrespective of the physiological index reclassification of angiogram-based treatment strategy increased with the number of lesions evaluated.