Impact of Tricuspid Regurgitation on Outcomes After Transcatheter Mitral Valve Replacement.

Development of functional tricuspid regurgitation (TR) because of chronic mitral disease and subsequent heart failure is common. However, the effect of TR on clinical outcomes after transcatheter mitral valve replacement (TMVR) remains unclear. We aimed to evaluate the impact of baseline TR on outcomes after TMVR. This was a single-center, retrospective analysis of patients who received valve-in-valve or valve-in-ring TMVR between 2012 and 2022. Patients were categorized into none/mild TR and moderate/severe TR based on baseline echocardiography. The primary outcome was 3 years all-cause death and the secondary outcomes were in-hospital events. Of the 135 patients who underwent TMVR, 64 (47%) exhibited none/mild TR at baseline, whereas 71 (53%) demonstrated moderate/severe TR. There were no significant differences in in-hospital events between the groups. At 3 years, the moderate/severe TR group exhibited a significantly increased risk of all-cause death (adjusted hazard ratio 3.37, 95% confidence interval 1.35 to 8.41, p = 0.009). When patients with baseline moderate/severe TR were stratified by echocardiography at 30 days into improved (36%) and nonimproved (64%) TR groups, although limited by small sample size, there was no significant difference in 3-year all-cause mortality (p = 0.48). In conclusion, this study investigating the impact of baseline TR on clinical outcomes revealed that moderate/severe TR is prevalent in those who underwent TMVR and is an independent predictor of 3-year all-cause mortality. Earlier mitral valve intervention before the development of significant TR may play a pivotal role in improving outcomes after TMVR.

Transcatheter Myotomy to Reduce Left Ventricular Outflow Obstruction.

BACKGROUND: Left ventricular outflow tract (LVOT) obstruction is a source of morbidity in hypertrophic cardiomyopathy (HCM) and a life-threatening complication of transcatheter mitral valve replacement (TMVR) and transcatheter aortic valve replacement (TAVR). Available surgical and transcatheter approaches are limited by high surgical risk, unsuitable septal perforators, and heart block requiring permanent pacemakers. OBJECTIVES: The authors report the initial experience of a novel transcatheter electrosurgical procedure developed to mimic surgical myotomy. METHODS: We used septal scoring along midline endocardium (SESAME) to treat patients, on a compassionate basis, with symptomatic LVOT obstruction or to create space to facilitate TMVR or TAVR. RESULTS: In this single-center retrospective study between 2021 and 2023, 76 patients underwent SESAME. In total, 11 (14%) had classic HCM, and the remainder underwent SESAME to facilitate TMVR or TAVR. All had technically successful SESAME myocardial laceration. Measures to predict post-TMVR LVOT significantly improved (neo-LVOT 42 mm2 [Q1-Q3: 7-117 mm2] to 170 mm2 [Q1-Q3: 95-265 mm2]; P < 0.001; skirt-neo-LVOT 169 mm2 [Q1-Q3: 153-193 mm2] to 214 mm2 [Q1-Q3: 180-262 mm2]; P < 0.001). Among patients with HCM, SESAME significantly decreased invasive LVOT gradients (resting: 54 mm Hg [Q1-Q3: 40-70 mm Hg] to 29 mm Hg [Q1-Q3: 12-36 mm Hg]; P = 0.023; provoked 146 mm Hg [Q1-Q3: 100-180 mm Hg] to 85 mm Hg [Q1-Q3: 40-120 mm Hg]; P = 0.076). A total of 74 (97.4%) survived the procedure. Five experienced 3 of 76 (3.9%) iatrogenic ventricular septal defects that did not require repair and 3 of 76 (3.9%) ventricular free wall perforations. Neither occurred in patients treated for HCM. Permanent pacemakers were required in 4 of 76 (5.3%), including 2 after concomitant TAVR. Lacerations were stable and did not propagate after SESAME (remaining septum: 5.9 ± 3.3 mm to 6.1 ± 3.2 mm; P = 0.8). CONCLUSIONS: With further experience, SESAME may benefit patients requiring septal reduction therapy for obstructive hypertrophic cardiomyopathy as well as those with LVOT obstruction after heart valve replacement, and/or can help facilitate transcatheter valve implantation.

Transcatheter Paravalvular Leak Closure With Covered Stent Tract and Vascular Plug: Tootsie Roll Technique.

BACKGROUND: Transcatheter closure of transcatheter heart valve (THV)-related paravalvular leak (PVL) is associated with a high failure rate with available devices due to the complex interaction of THV and aortic/mitral annulus. OBJECTIVES: This study reports on novel transcatheter techniques to treat PVL after THV. METHODS: The authors describe consecutive patients who underwent PVL closure after transcatheter aortic valve replacement (TAVR) or transcatheter mitral valve replacement (TMVR). A covered self-expanding stent (Viabahn) was deployed in the defect to create a seal between the THV and annulus. A vascular plug (Amplatzer Vascular Plug 2 [AVP2] or AVP4) was then deployed inside the covered stent to obliterate PVL. RESULTS: Eight patients with THV-related PVL were treated using this method (aortic [3 SAPIEN, 1 Evolut], mitral [2 SAPIEN-in-MAC (mitral annular calcification), 2 M3 TMVR). Various combinations of stents and plugs were used (5 mm × 2.5 cm Viabahn + 6 mm AVP4 [n = 2], 8 mm × 2.5 cm Viabahn + 10 mm AVP2 [n = 5], and 10 mm × 5.0 cm Viabahn + 12 mm AVP2 [n = 1]). All had technical success with immediate elimination of target PVL, without in-hospital complications. None had signs of postprocedure hemolysis. All patients were discharged alive (median 3.5 days [Q1-Q3: 1.0-4.8 days]). No residual PVL was seen at discharge, except for 1 patient with mild regurgitation due to another untreated PVL location. One patient died before 30 days due to complication of valve-in-MAC TMVR. In remaining patients, none had recurrence of PVL at 30 days. Symptoms decreased to NYHA functional class I/II in 6 patients. NYHA functional class III symptoms remained in 1 patient with mitral regurgitation awaiting subsequent valve replacement procedure. CONCLUSIONS: The technique of sequential deployment of a covered stent and vascular plug may effectively treat THV-related PVL.

Hybrid Closure of Postinfarction Apical Ventricular Septal Defect Using Septal Occluder Device and Right Ventricular Free Wall: The Apical BASSINET Concept.

BACKGROUND: Postinfarction ventricular septal defect (VSD) is a catastrophic complication of myocardial infarction. Surgical repair still has poor outcomes. This report describes clinical outcomes after a novel hybrid transcatheter/surgical repair in patients with apical VSD. METHODS: Seven patients with postmyocardial infarction apical VSD underwent hybrid transcatheter repair via subxiphoid surgical access. A transcatheter occluder (Amplatzer Septal Occluder) with a trailing premounted suture was deployed through the right ventricular wall and through the ventricular septum into the left ventricular apex. The trailing suture was used to connect an anchor external to the right ventricular wall. Tension on the suture then collapses the right ventricular free wall against the septum and left ventricular occluder, thereby obliterating the VSD. Outcomes were compared with 9 patients who underwent surgical repair using either patch or primary suture closure. RESULTS: All patients had significant left-to-right shunt (Qp:Qs 2.5:1; interquartile range [IQR, 2.1-2.6] hybrid repair versus 2.0:1 [IQR, 2.0-2.5] surgical repair), and elevated right ventricular systolic pressure (62 [IQR, 46-71] versus 49 [IQR, 43-54] mm Hg, respectively). All had severely depressed stroke volume index (22 versus 21 mL/m2) with ≈45% in each group requiring mechanical support preprocedurally. The procedure was done 15 (IQR, 10-50) versus 24 (IQR, 10-134) days postmyocardial infarction, respectively. Both groups of patients underwent repair with technical success and without intraprocedural death. One patient in the hybrid group and 4 in the surgical group developed multiorgan failure. The hybrid group had a higher survival at discharge (86% versus 56%) and at 30 days (71% versus 56%), but similar at 1 year (57% versus 56%). During follow-up, 1 patient in each group required reintervention for residual VSD (hybrid: 9 months versus surgical: 5 days). CONCLUSIONS: Early intervention with a hybrid transcatheter/surgical repair may be a viable alternative to traditional surgery for postinfarction apical VSD.

Transcatheter Mitral Valve Therapy in the United States: A Report from the STS/ACC TVT Registry.

Data for nearly all patients undergoing transcatheter edge-to-edge repair (TEER) and transcatheter mitral valve replacement (TMVR) with an approved device in the United States is captured in the Society of Thoracic Surgeons/American College of Cardiology Transcatheter Valve Therapy Registry. All data submitted for TEER or TMVR between 2014 and March 31, 2020, are reported. A total of 37,475 patients underwent a mitral transcatheter procedure, including 33,878 TEER and 3,597 TMVR. Annual procedure volumes for TEER have increased from 1,152 per year in 2014 to 10,460 per year in 2019 at 403 sites and for TMVR from 84 per year to 1,120 per year at 301 centers. Mortality rates have decreased for TEER at 30 days (5.6%-4.1%) and 1 year (27.4%-22.0%). Early off-label use data on TMVR in mitral valve-in-valve therapy led to approval by the U.S. Food and Drug Administration in 2017, and the 2019 30-day mortality rate was 3.9%. Overall improvements in outcomes over the last 6 years are apparent. (STS/ACC TVT Registry Mitral Module; NCT02245763).

Transcatheter Mitral Valve Therapy in the United States: A Report From the STS-ACC TVT Registry.

Data for nearly all patients undergoing transcatheter edge-to-edge repair (TEER) and transcatheter mitral valve replacement (TMVR) with an approved device in the United States is captured in the Society of Thoracic Surgeons/American College of Cardiology Transcatheter Valve Therapy Registry. All data submitted for TEER or TMVR between 2014 and March 31, 2020, are reported. A total of 37,475 patients underwent a mitral transcatheter procedure, including 33,878 TEER and 3,597 TMVR. Annual procedure volumes for TEER have increased from 1,152 per year in 2014 to 10,460 per year in 2019 at 403 sites and for TMVR from 84 per year to 1,120 per year at 301 centers. Mortality rates have decreased for TEER at 30 days (5.6%-4.1%) and 1 year (27.4%-22.0%). Early off-label use data on TMVR in mitral valve-in-valve therapy led to approval by the U.S. Food and Drug Administration in 2017, and the 2019 30-day mortality rate was 3.9%. Overall improvements in outcomes over the last 6 years are apparent. (STS/ACC TVT Registry Mitral Module; NCT02245763).

Comparison of Transvalvular Aortic Mean Gradients Obtained by Intraprocedural Echocardiography and Invasive Measurement in Balloon and Self-Expanding Transcatheter Valves.

Background Concerns about discordance between echocardiographic and invasive mean gradients after transcatheter aortic valve replacement (TAVR) with balloon-expandable valves (BEVs) versus self-expanding valves (SEVs) exist. Methods and Results In a multicenter study, direct-invasive and echocardiography-derived transvalvular mean gradients obtained before and after TAVR were compared as well as post-TAVR and discharge echocardiographic mean gradients in BEVs versus SEVs in 808 patients. Pre-TAVR, there was good correlation (R=0.614; P<0.0001) between direct-invasive and echocardiography-derived mean gradients and weak correlation (R=0.138; P<0.0001) post-TAVR. Compared with post-TAVR echocardiographic mean gradients, both valves exhibit lower invasive and higher discharge echocardiographic mean gradients. Despite similar invasive mean gradients, a small BEV exhibits higher post-TAVR and discharge echocardiographic mean gradients than a large BEV, whereas small and large SEVs exhibit similar post-TAVR and discharge mean gradients. An ejection fraction <50% (P=0.028) and higher Society of Thoracic Surgeons predicted risk of mortality score (P=0.007), but not invasive or echocardiographic mean gradient ≥10 mm Hg (P=0.378 and P=0.341, respectively), nor discharge echocardiographic mean gradient ≥20 mm Hg (P=0.393), were associated with increased 2-year mortality. Conclusions Invasively measured and echocardiography-derived transvalvular mean gradients correlate well in aortic stenosis but weakly post-TAVR. Post-TAVR, echocardiography overestimates transvalvular mean gradients compared with invasive measurements, and poor correlation suggests these modalities cannot be used interchangeably. Moreover, echocardiographic mean gradients are higher on discharge than post-TAVR in all valves. Despite similar invasive mean gradients, a small BEV exhibits higher post-TAVR and discharge echocardiographic mean gradients than a large BEV, whereas small and large SEVs exhibit similar post-TAVR and discharge mean gradients. Immediately post-TAVR, elevated echocardiographic-derived mean gradients should be assessed with caution and compared with direct-invasive mean gradients. A low ejection fraction and higher Society of Thoracic Surgeons score, but not elevated mean gradients, are associated with increased 2-year mortality.

Prevalence of coronary risk factors in contemporary practice among patients undergoing their first percutaneous coronary intervention: Implications for primary prevention.

BACKGROUND: Cigarette smoking, hypertension, dyslipidemia, diabetes, and obesity are conventional risk factors (RFs) for coronary artery disease (CAD). Population trends for these RFs have varied in recent decades. Consequently, the risk factor profile for patients presenting with a new diagnosis of CAD in contemporary practice remains unknown. OBJECTIVES: To examine the prevalence of RFs and their temporal trends among patients without a history of myocardial infarction or revascularization who underwent their first percutaneous coronary intervention (PCI). METHODS: We examined the prevalence and temporal trends of RFs among patients without a history of prior myocardial infarction, PCI, or coronary artery bypass graft surgery who underwent PCI at 47 non-federal hospitals in Michigan between 1/1/2010 and 3/31/2018. RESULTS: Of 69,571 men and 38,930 women in the study cohort, 95.5% of patients had 1 or more RFs and nearly half (55.2% of women and 48.7% of men) had ≥3 RFs. The gap in the mean age at the time of presentation between men and women narrowed as the number of RFs increased with a gap of 6 years among those with 2 RFs to <1 year among those with 5 RFs. Compared with patients without a current/recent history of smoking, those with a current/recent history of smoking presented a decade earlier (age 56.8 versus 66.9 years; p <0.0001). Compared with patients without obesity, patients with obesity presented 4.0 years earlier (age 61.4 years versus 65.4 years; p <0.0001). CONCLUSIONS: Modifiable RFs are widely prevalent among patients undergoing their first PCI. Smoking and obesity are associated with an earlier age of presentation. Population-level interventions aimed at preventing obesity and smoking could significantly delay the onset of CAD and the need for PCI.

Preventing Coronary Obstruction During Transcatheter Aortic Valve Replacement: Results From the Multicenter International BASILICA Registry.

OBJECTIVES: This study sought to determine the safety of the BASILICA (bioprosthetic or native aortic scallop intentional laceration to prevent iatrogenic coronary artery obstruction) procedure. BACKGROUND: Transcatheter aortic valve replacement causes coronary artery obstruction in 0.7% of cases, with 40% to 50% mortality. BASILICA is a procedure to prevent coronary obstruction. Safety and feasibility in a large patient cohort is lacking. METHODS: The international BASILICA registry was a retrospective, multicenter, real-world registry of patients at risk of coronary artery obstruction undergoing BASILICA and transcatheter aortic valve replacement. Valve Academic Research Consortium-2 definitions were used to adjudicate events. RESULTS: Between June 2017 and December 2020, 214 patients were included from 25 centers in North America and Europe; 72.8% had bioprosthetic aortic valves and 78.5% underwent solo BASILICA. Leaflet traversal was successful in 94.9% and leaflet laceration in 94.4%. Partial or complete coronary artery obstruction was seen in 4.7%. Procedure success, defined as successful BASILICA traversal and laceration without mortality, coronary obstruction, or emergency intervention, was achieved in 86.9%. Thirty-day mortality was 2.8% and stroke was 2.8%, with 0.5% disabling stroke. Thirty-day death and disabling stroke were seen in 3.4%. Valve Academic Research Consortium-2 composite safety was achieved in 82.8%. One-year survival was 83.9%. Outcomes were similar between solo and doppio BASILICA, between native and bioprosthetic valves, and with the use of cerebral embolic protection. CONCLUSIONS: BASILICA is safe, with low reported rates of stroke and death. BASILICA is feasible in the real-world setting, with a high procedure success rate and low rates of coronary artery obstruction.

Invasive versus echocardiographic gradients in degenerated surgical aortic valve prostheses: A multicenter study.

Objectives: To compare echocardiographic and invasive mean gradients obtained concomitantly in degenerated bioprosthetic surgical aortic valves (SAVRs). Methods: In a multicenter study, we compared concomitant echocardiographic and invasive mean gradients of SAVR, obtained before valve-in-valve transcatheter aortic valve replacement in all patients, patients with primary stenosis (AS), primary aortic regurgitation (AR), and mixed aortic valve disease (MAVD), and in small versus large valves (≤ or >23 mm). Dimensionless index (DI) was calculated in all groups. Results: In total, 74 patients were included and data presented as median (interquartile range). Echocardiography-catheterization mean gradient discordance was observed in all patients (invasive = 22 mm Hg [11-34] vs echocardiographic = 32 mm Hg [21-42], P = .013), small valves (invasive = 15 mm Hg [8-34] vs echocardiographic = 28 mm Hg [21-41], P = .013), and large valves (invasive = 20 mm Hg [8.5-27.13] vs echocardiographic = 32 mm Hg [25.5 - 41.5], P < .0001), with a bias of 8 ± 15 mm Hg and wide limits of agreement (-22 to 39 mm Hg) on Bland-Altman plots, indicating these modalities may not be interchangeable. Discordance occurred in AR (invasive = 3 mm Hg [1-6] vs echocardiographic = 12 mm Hg [7-22], P = .017) and in MAVD (invasive = 19 mm Hg [12-29] vs echocardiographic = 31 mm Hg [23-39], P < .0001) but not in AS (invasive = 35 mm Hg [24-45] vs echocardiographic = 41 mm Hg [30-50], P = .45). A lower DI (0.21 [0.14-0.25]) occurred in AS compared with MAVD (0.31 [0.19-0.39]) and AR (0.55 [0.51-0.69]), P < .0001. Conclusions: Discordance between echocardiography and invasive mean gradients exists in degenerated SAVR, regardless of valve size, but depends on mechanism of failure and DI helps stratify these patients. With a discrepancy between echocardiographic mean gradients AND the patient's symptoms OR the valve leaflet structure and/or mobility on imaging, especially before redo-SAVR or valve-in-valve transcatheter aortic valve replacement, invasive gradients may adjudicate the true valvular hemodynamics.

STS-ACC TVT Registry of Transcatheter Aortic Valve Replacement.

The STS-ACC TVT Registry (Society of Thoracic Surgeons-American College of Cardiology Transcatheter Valve Therapy Registry) from 2011 to 2019 has collected data on 276,316 patients undergoing transcatheter aortic valve replacement (TAVR) at sites in all U.S. states. Volumes have increased every year, exceeding surgical aortic valve replacement in 2019 (72,991 vs. 57,626), and it is now performed in all U.S. states. TAVR now extends from extreme- to low-risk patients. This is the first presentation on 8,395 low-risk patients treated in 2019. In 2019, for the entire cohort, femoral access increased to 95.3%, hospital stay was 2 days, and 90.3% were discharged home. Since 2011, the 30-day mortality rate has decreased (7.2% to 2.5%), stroke has started to decrease (2.75% to 2.3%), but pacemaker need is unchanged (10.9% to 10.8%). Alive with acceptable patient-reported outcomes is achieved in 8 of 10 patients at 1 year. The Registry is a national resource to improve care and analyze TAVR's evolution. Real-world outcomes, site performance, and the impact of coronavirus disease 2019 will be subsequently studied. (STS/ACC Transcatheter Valve Therapy Registry [TVT Registry]; NCT01737528).

STS-ACC TVT Registry of Transcatheter Aortic Valve Replacement.

The STS-ACC TVT Registry (Society of Thoracic Surgeons-American College of Cardiology Transcatheter Valve Therapy Registry) from 2011 to 2019 has collected data on 276,316 patients undergoing transcatheter aortic valve replacement (TAVR) at sites in all U.S. states. Volumes have increased every year, exceeding surgical aortic valve replacement in 2019 (72,991 vs. 57,626), and it is now performed in all U.S. states. TAVR now extends from extreme- to low-risk patients. This is the first presentation on 8,395 low-risk patients treated in 2019. In 2019, for the entire cohort, femoral access increased to 95.3%, hospital stay was 2 days, and 90.3% were discharged home. Since 2011, the 30-day mortality rate has decreased (7.2% to 2.5%), stroke has started to decrease (2.75% to 2.3%), but pacemaker need is unchanged (10.9% to 10.8%). Alive with acceptable patient-reported outcomes is achieved in 8 of 10 patients at 1 year. The Registry is a national resource to improve care and analyze TAVR's evolution. Real-world outcomes, site performance, and the impact of coronavirus disease 2019 will be subsequently studied. (STS/ACC Transcatheter Valve Therapy Registry [TVT Registry]; NCT01737528).

Hemodynamic principles of prosthetic aortic valve evaluation in the transcatheter aortic valve replacement era.

Evaluating the hemodynamic performance of aortic valve prostheses has relied primarily on echocardiography. This involves calculating the trans-prosthetic valve mean gradient (MG) and aortic valve area (AVA), and assessing for valvular and paravalvular regurgitation in a fashion similar to the native aortic valve. In conjunction with other echocardiographic and nonechocardiographic parameters, MG and AVA are used to distinguish between prosthesis stenosis, prosthesis patient mismatch, pressure recovery, increased flow, and measurement errors. This review will discuss the principles and limitations of echocardiographic evaluation of aortic valve prosthesis following surgical, and transcatheter aortic valve replacement and in comparison to invasive hemodynamics through illustrative clinical cases.

Transfemoral Transcatheter Aortic Valve Replacement Using Fascia Iliaca Block as an Alternative Approach to Conscious Sedation as Compared to General Anesthesia.

BACKGROUND/PURPOSE: General Anesthesia (GA) and conscious sedation (CS) are anesthetics for transfemoral transcatheter aortic valve replacement (TF-TAVR). We compared TF-TAVR outcomes using a novel anesthetic approach with fascia iliaca block (FIB) plus minimal CS (MCS) versus GA. METHODS: This retrospective propensity-matched study included consecutive TF-TAVR patients from January 2013 to December 2017 and dichotomized into FIB-MCS vs. GA. Data were collected from electronic records, Society of Thoracic Surgery (STS) database, and the Transcatheter Valve Therapies (TVT) Registry. Primary endpoints were operating room (OR) time, intensive care unit (ICU) and hospital length of stay (LOS). Secondary endpoints were 30-day, 1-year mortality, quality of life, 30-day re-hospitalization rate, failure of FIB-MCS, and hospital safety outcomes. RESULTS: A total of 304 TF-TAVR patients; FIB-MCS (n = 219) vs. GA (n = 85). Propensity matched 162 patients; FIB-MCS (n = 108) vs. GA (n = 54). FIB-MCS had shorter OR time (197.6 ±â€¯56.3 vs. 248.2 ±â€¯46.3 min, p < 0.001), ICU (67.8 ±â€¯71.7 vs. 84.9 ±â€¯72.1 h, p = 0.004) and hospital LOS (3.2 ±â€¯3.7 vs. 5.9 ±â€¯3.5 d, p < 0.001). FIB-MCS had lower rate of blood transfusion. FIB-MCA vs. GA 30-day and 1-year mortality were similar in the entire (2.3 vs. 2.4%, p = 1.0; and 8.2 vs. 5.9%, p = 0.49) and matched cohorts (0 vs. 3.7%, p = 0.11 and 7.4 vs. 5.6%, p = 0.75). FIB-MCS were less likely to be re-hospitalized [Odd Ratio: 0.32, CI:0.13-0.76] and 2% to 3% higher KCCQ-12 score. CONCLUSION: TF-TAVR using FIB-MCS is feasible and safe with shorter OR time, ICU and hospital LOS, lower risk of 30-day re-hospitalization, similar 30-day and 1-year mortality with better quality of life at 1-year follow-up.

Optimizing the Technique for Invasive Fractional Flow Reserve to Assess Lesion-Specific Ischemia.

BACKGROUND: Invasive fractional flow reserve (FFRINV) is the standard technique for assessing myocardial ischemia. Pressure distortions and measurement location may influence FFRINV interpretation. We report a technique for performing invasive fractional flow reserve (FFRINV) by minimizing pressure distortions and identifying the proper location to measure FFRINV. METHODS: FFRINV recordings were obtained prospectively during manual hyperemic pullback in 100 normal and diseased coronary arteries with single stenosis, using 4 measurements from the terminal vessel, distal-to-the-lesion, proximal vessel, and guiding catheter. FFRINV profiles were developed by plotting FFRINV values (y-axis) and site of measurement (x-axis), stratified by stenosis severity. FFRINV≤0.8 was considered positive for lesion-specific ischemia. RESULTS: Erroneous FFRINV values were observed in 10% of vessels because of aortic pressure distortion and in 21% because of distal pressure drift; these were corrected by disengagement of the guiding catheter and re-equalization of distal pressure/aortic pressure, respectively. There were significant declines in FFRINV from the proximal to the terminal vessel in normal and stenotic coronary arteries (P<0.001). The rate of positive FFRINV was 41% when measured from the terminal vessel and 20% when measured distal-to-the-lesion (P<0.001); 41.5% of positive terminal measurements were reclassified to negative when measured distal-to-the-lesion. Measuring FFRINV 20 to 30 mm distal-to-the-lesion (rather than from the terminal vessel) can reduce errors in measurement and optimize the assessment of lesion-specific ischemia. CONCLUSIONS: Meticulous technique (disengagement of the guiding catheter, FFRINV pullback) is required to avoid erroneous FFRINV, which occur in 31% of vessels. Even with optimal technique, FFRINV values are influenced by stenosis severity and the site of pressure measurement. FFRINV values from the terminal vessel may overestimate lesion-specific ischemia, leading to unnecessary revascularization.