Rationale and Design of Prospective, Multicenter, Double-Arm Clinical Trial to Investigate the Efficacy of Tofogliflozin on Left Ventricular Diastolic Dysfunction in Patients with Heart Failure with Preserved Ejection Fraction and Type 2 Diabetes Mellitus (TOP-HFPEF Trial).

BACKGROUND: Recent large clinical trials have revealed that sodium-glucose cotransporter 2 (SGLT2) inhibitors improve cardiovascular outcomes not only in patients with heart failure with reduced ejection fraction, but also in patients with heart failure with mildly reduced or preserved ejection fraction (HFpEF). However, the effect of SGLT2 inhibitors on left ventricular (LV) diastolic function is still controversial. METHODS AND RESULTS: The TOP-HFPEF trial (Efficacy of Tofogliflozin on Left Ventricular Diastolic Dysfunction in Patients with Heart Failure with Preserved Ejection Fraction and Type 2 Diabetes Mellitus) is a multicenter, double-arm, open-label, confirmatory, investigator-initiated clinical study to investigate the effect of SGLT2 inhibitor on LV diastolic function in patients with HFpEF and type 2 diabetes mellitus. The participants are randomly assigned (1:1) to the tofogliflozin group (20 mg once daily) or the control group (administration or continuation of antidiabetic drugs other than SGLT2 inhibitors). The estimated number of patients to be enrolled in this trial is 90 in total (45 in each group). The participants are followed up for 52 weeks with tofogliflozin or control drugs. The primary endpoint is the change in E/e' assessed by echocardiography from the baseline to the end of this study (52 weeks). This trial will also evaluate the effects of tofogliflozin on cardiovascular events, biomarkers, other echocardiographic parameters, the occurrence of atrial fibrillation, and renal function. CONCLUSIONS: The TOP-HFPEF trial will clarify the efficacy of an SGLT2 inhibitor, tofogliflozin, on LV diastolic function in patients with HFpEF and type 2 diabetes mellitus.

Relative B-Type Natriuretic Peptide Deficiency May Exist in Diastolic Dysfunction in Subclinical Population.

Background: Heart failure patients are deficient in B-type natriuretic peptide (BNP) but the significance of subclinical BNP deficiency is unclear. Methods and Results: A total of 1,398 subjects without cardiovascular disease, with left ventricular ejection fraction (LVEF) ≥50% and BNP level <100 pg/mL, were selected from a 2005-2008 health checkup in Arita-cho, Japan, and divided into 2 groups: with and without LV diastolic dysfunction (DD+ or DD-). We performed propensity score matching on non-cardiac factors affecting BNP levels and analyzed 470 subjects in each group (372/940 men; median age, 66 years). The DD(+) group showed higher lateral E/e', an index of estimated left ventricular filling pressure, and greater prevalence of concentric hypertrophy (CH) despite similar BNP levels, suggesting a relative deficiency of BNP in DD(+) compared with DD(-). Multivariable logistic regression analysis revealed an increase in BNP correlated with decreased odds of CH (adjusted odds ratio [aOR] 0.663, 95% confidence interval (CI) 0.484-0.909, P=0.011), whereas an increase in lateral E/e' was associated with increased odds of CH (aOR, 2.881; 95% CI, 1.390-5.973; P=0.004). Furthermore, CH in combination with diastolic dysfunction independently predicted major adverse cardiovascular events (hazard ratio 3.272, 95% CI 1.215-8.809; P=0.019). Conclusions: Relative BNP deficiency was associated with CH, which had a poor prognosis in patients with diastolic dysfunction.

Accuracy of Shunt Volume Measured by Three-Dimensional Echocardiography and Cardiac Magnetic Resonance in Patients with an Atrial Septal Defect and a Dilated Right Ventricle.

BACKGROUND: The accuracy of right ventricular (RV) quantification by three-dimensional echocardiography (3DE) has been reported mainly in patients with a normal RV. However, there are no data regarding the accuracy of 3DE in patients with a dilated RV, as in shunt diseases. In this study, we evaluated the accuracy of 3DE and that of volumetric cardiac magnetic resonance (CMR) for assessment of RV and left ventricular (LV) stroke volume (SV) and the pulmonary (Qp)/systemic (Qs) blood flow ratio in patients with an atrial septal defect (ASD) using the two-dimensional phase contrast (2DPC) method as the gold standard. METHODS: We retrospectively investigated 83 patients with ASD who underwent transcatheter closure and clinically indicated CMR and 3DE examinations. Qp/Qs was calculated using RV and LV SV measured by full-volume volumetric 3DE (Vol-3DE) and CMR (Vol-CMR) and by two-dimensional pulse Doppler quantification (2D-Dop); the parameters were compared using 2DPC-CMR as the gold standard. RESULTS: There was no significant difference in the Qp/Qs value between 2DPC-CMR and Vol-3DE (2.29 ± 0.70 vs. 2.21 ± 0.63, P=0.79) and 2D-Dop (vs. 2.21 ± 0.65, P=1.00); however, a significant difference was found between 2DPC-CMR and Vol-CMR (P<0.001). The Qp/Qs value obtained using Vol-3DE showed the best correlation with 2DPC-CMR (r=0.93, P<0.001). The RV and LV SV values obtained by Vol-3DE showed the best correlation with 2DPC-CMR (RV SV, r=0.82, P<0.001; LV SV, r=0.73, P<0.001), although the absolute values were underestimated. CONCLUSION: Qp/Qs was more accurately evaluated by Vol-3DE than by Vol-CMR or 2D-Dop. 3DE assessment was feasible and reproducible even in a dilated RV.

Sex-Specific Left Ventricular and Aorta Size Cut-Off Values for Hemodynamically Significant Chronic Aortic Regurgitation　- Implications for Treatment in Asian Populations.

BACKGROUND: There are no sex-specific guidelines for chronic aortic regurgitation (AR). This retrospective study examined sex-specific differences and propose treatment criteria from an Asian AR cohort.Methods and Results: Consecutive 1,305 patients with moderate-severe AR or greater at 3 tertiary centers in Taiwan and Japan (2008-2022) were identified. Study endpoints were aortic valve surgery (AVS), all-cause death (ACD), and cardiovascular death (CVD). The median follow up was 3.9 years (interquartile range 1.3-7.1 years). Compared with men (n=968), women (n=337) were older, had more advanced symptoms, more comorbidities, larger indexed aorta size (iAortamax) and indexed left ventricular (LV) end-systolic dimension (LVESDi; P<0.001 for all). Symptomatic status was poorly correlated with the degree of LV remodeling in women (P≥0.18). Women received fewer AVS (P≤0.001) and men had better overall 10-year survival (P<0.01). Ten-year post-AVS survival (P=0.9) and the progression of LV remodeling were similar between sexes (P≥0.16). Multivariable determinants of ACD and CVD were age, advanced symptoms, iAortamax, LV ejection fraction (LVEF), LVESDi, LV end-systolic volume index (LVESVi), and Taiwanese ethnicity (all P<0.05), but not female sex (P≥0.05). AVS was associated with better survival (P<0.01). Adjusted LVEF, LVESDi, LVESVi, and iAortamaxcut-off values for ACD were 53%, 24.8 mm/m2, 44 mL/m2, and 25.5 mm/m2, respectively, in women and 52%, 23.4 mm/m2, 52 mL/m2, and 23.2 mm/m2, respectively, in men. CONCLUSIONS: Early detection and intervention using sex-specific cut-off values may improve survival in women with AR.

Prognostic value of E/e' ratio and its change over time in ST-segment elevation myocardial infarction with preserved left ventricular ejection fraction in the reperfusion era.

BACKGROUND: The ratio of early diastolic mitral inflow velocity to mitral annular velocity (E/e') is a prognostic factor in patients with ST-segment elevation myocardial infarction (STEMI). However, data are lacking on long-term outcomes and longitudinal changes in E/e' in patients with preserved left ventricular ejection fraction (LVEF) in the reperfusion era. METHODS: This is a pre-specified echocardiographic substudy of a randomized controlled trial evaluating the efficacy of beta-blockers in STEMI patients with LVEF ≥40 % after primary percutaneous coronary intervention (PCI). Patients were divided into 2 groups according to E/e' at discharge: ≤14 (normal E/e' group) or > 14 (high E/e' group). The primary outcome was a composite of all-cause death, myocardial infarction, stroke, acute coronary syndrome, and heart failure hospitalization. We also assessed longitudinal changes in E/e' and conducted a landmark analysis using E/e' at 1 year after STEMI. RESULTS: There were 173 and 38 patients in the normal and high E/e' groups, respectively. During a median follow-up of 3.9 years, the primary outcome occurred in 19 patients (11.0 %) and 10 patients (26.3 %) in the normal and high E/e' groups, respectively. The cumulative incidence of the primary outcome was higher in the high E/e' group than in the normal E/e' group (21.9 % vs. 7.1 % at 3 years; log-rank p = 0.013). E/e' in the high E/e' group decreased over time (p < 0.001), but remained higher than in the normal E/e' group at 1 year after STEMI (13.7 ±â€¯5.3 vs. 8.6 ±â€¯2.3, p < 0.001). E/e' > 14 at 1 year was also associated with poor outcomes (log-rank p = 0.008). A sensitivity analysis using multivariate Cox proportional hazards regression models yielded consistent results. CONCLUSION: High E/e' at discharge is associated with poor long-term outcomes in STEMI patients with preserved LVEF after primary PCI, which may be explained by persistent high E/e' late after STEMI.

Multi-modal treatment in a pregnant woman with untreated cardiac sarcoidosis complicated by cardiac dysfunction and ventricular arrhythmias: a case report and literature review.

Background: The treatment of cardiac sarcoidosis during pregnancy is inherently challenging owing to its impact on the foetus. Case summary: We report a case of a 30-year-old pregnant woman with untreated cardiac sarcoidosis. One year prior to admission, she underwent permanent pacemaker implantation for complete atrioventricular block. Left ventricular ejection fraction (EF) showed a declining trend, and ventricular tachycardia (VT) was documented. Following an extensive evaluation, the patient was diagnosed with active cardiac sarcoidosis, and the pregnancy was detected at the same time. Considering the high risk of mortality and cardiovascular complications in pregnant patients with decreased EF and VT, we meticulously discussed the optimal timing of multi-modal treatment, including bisoprolol, eplerenone, sotalol, and prednisolone and cardiac resynchronization therapy with a defibrillator, and its effect on the foetus. These interventions improved the EF to 49%, and the baby was successfully delivered without adverse events or neonatal complications developing. At 8 months' post-partum, the mother and the baby were doing well, and the EF was 45%. Discussion: Cardiac sarcoidosis can lead to adverse outcomes for both the mother and the foetus. However, with multi-modal treatment individually optimized and implemented by a multi-disciplinary team of specialists in each field, even pregnant women with untreated cardiac sarcoidosis who present with reduced EF and VT can achieve safe childbirth.

Mitral valve early systolic billowing induces following annular expansion and leaflet augmentation in Barlow's disease: sequential analysis using 3D echocardiography.

AIMS: Although systolic expansion of the annulus has been recognized in Barlow's disease, the mechanisms of the unique pathological movement of the annulus and its relation to the leaflet augmentation have not yet been clarified. We aimed to investigate the detailed mechanisms of the characteristic mitral apparatus dynamics in Barlow's disease by frame-by-frame sequential geometric analysis using real-time 3D transoesophageal echocardiography. METHODS AND RESULTS: Fifty-three patients with Barlow's disease and severe mitral regurgitation without torn chordae, as well as 10 controls, were included. We evaluated geometric changes in the mitral complex using 3D transoesophageal echocardiography at five points during systole. To identify early systolic billowing of leaflets, the annulo-leaflet angle was measured. We also performed a more detailed analysis in four consecutive frames just before and after leaflet free-edge prolapse above the annulus plane. The median annulo-leaflet angle of both leaflets in early systole was >0° (above annulus plane) in patients with Barlow's disease, and billowing of the leaflet body was observed from early systole. The prolapse volume of both leaflets increased markedly from early to mid-systole [1.60 (0.85-2.80) to 4.00 (2.10-6.45) mL; analysis of variance (ANOVA), P < 0.001; post hoc, P < 0.05]. With frame-by-frame analysis, dynamic augmentation of the annulus and leaflets developed between frames just before and just after leaflet free-edge prolapse (ANOVA, P < 0.01; post hoc, P < 0.05). CONCLUSION: In Barlow's disease, early systolic billowing of the mitral leaflet induces systolic annulus expansion followed by leaflet augmentation and leaflet free-edge prolapse.

Cardioembolism after thoracoscopic left atrial appendage clipping in a patient on oral anticoagulation therapy.

Cardioembolism associated with atrial fibrillation is a major cause of ischemic stroke. Left atrial appendage occlusion in atrial fibrillation patients undergoing cardiac surgery reduces the risk of postoperative stroke. A 78-year-old man with a history of atrial fibrillation and severe mitral regurgitation underwent thoracoscopic mitral valve repair with left atrial appendage clipping and the cryo-maze procedure 4 years previously. He was taking a direct oral anticoagulant for stroke prevention because his atrial fibrillation had recurred. He presented with acute onset disturbed consciousness, omnidirectional gaze palsy, left facial palsy, severe dysarthria, bilateral limb ataxia, and sensory disturbance. National Institutes of Health Stroke Scale score was 16. Although non-contrast computed tomography showed no early ischemic changes, computed tomography angiography revealed occlusion of the basilar artery. Intravenous thrombolysis was performed, which resulted in recanalization. Transesophageal echocardiography showed left atrial spontaneous echo contrast and thrombus in the left atrial appendage. Contrast-enhanced chest computed tomography confirmed incomplete left atrial appendage occlusion. Cardioembolic stroke was diagnosed, and warfarin was initiated. Cardioembolism may occur after thoracoscopic left atrial appendage clipping despite direct oral anticoagulant therapy, particularly if appendage occlusion is incomplete. Occlusion status should be evaluated after thoracoscopic clipping. Learning objective: To illustrate, incomplete left atrial appendage closure may increase the risk of ischemic stroke even after thoracoscopic left atrial appendage clipping is performed to prevent embolism.

Radiofrequency Catheter Ablation for Atrial Fibrillation Patients on Hemodialysis (From the Kansai Plus Atrial Fibrillation Registry)　- Clinical Impact of Early Recurrence.

BACKGROUND: Catheter ablation (CA) for atrial fibrillation (AF) in patients on hemodialysis (HD) is reported to have a high risk of late recurrence (LR). However, the relationship between early recurrence (ER) within a 90-day blanking period after CA in AF patients and LR in HD patients remains unclear.Methods and Results: Of the 5,010 patients in the Kansai Plus Atrial Fibrillation Registry, 5,009 were included in the present study. Of these patients, 4,942 were not on HD (non-HD group) and 67 were on HD (HD group). HD was an independent risk factor for LR after the initial CA (adjusted hazard ratio 1.6; 95% confidence interval 1.1-2.2; P=0.01). In patients with ER, the rate of sinus rhythm maintenance at 3 years after the initial CA was significantly lower in the HD than non-HD group (11.4% vs. 35.4%, respectively; log-rank P=0.004). However, in patients without ER, there was no significant difference in the rate of sinus rhythm maintenance at 3 years between the HD and non-HD groups (67.7% vs. 74.5%, respectively; log-rank P=0.62). CONCLUSIONS: ER in HD patients was a strong risk factor for LR. However, even HD patients could expect a good outcome without ER after the initial CA.

Cost-effective analysis of transcatheter aortic valve replacement in patients with severe symptomatic aortic stenosis: A prospective multicenter study.

BACKGROUND: Transcatheter aortic valve replacement (TAVR) for severe symptomatic aortic stenosis (AS) does not benefit all patients. We performed a prospective multicenter study to investigate the cost-effectiveness of TAVR in a Japanese cohort. METHODS AND RESULTS: We prospectively enrolled 110 symptomatic patients with severe AS who underwent TAVR from five institutions. The quality of life measurement (QOL) was performed for each patient before and at 6 months after TAVR. Patients without an improvement in QOL at 6 months after TAVR were defined as non-responders. Pre-TAVR higher QOL, higher clinical frailty scale predicted the non-responders. Three models, 1) conservative treatment for all patients strategy, 2) TAVR for all patients strategy, and 3) TAVR for a selected patient strategy who is expected to be a responder, were simulated. Lifetime cost-effectiveness was estimated using incremental cost-effectiveness ratio (ICER) and cost per quality-adjusted life-year (QALY) gained. In comparison to conservative therapy for all patients, ICER was estimated to be 5,765,800 yen/QALY for TAVR for all patients and 2,342,175 yen/QALY for TAVR for selected patient strategy patients, which is less than the commonly accepted ICER threshold of 5,000,000 yen/QALY. CONCLUSIONS: TAVR for selected patient strategy model is more cost-effective than TAVR for all patient strategy without reducing QOL in the Japanese healthcare system. TAVR for selected patient strategy has potential benefit for optimizing the TAVR treatment in patients with high frailty and may direct our resources toward beneficial interventions.

Implications of ventricular arrhythmia after cardiac resynchronization therapy.

BACKGROUND: Conflicting data are available on whether ventricular arrhythmia (VA) or shock therapy increases mortality. Although cardiac resynchronization therapy (CRT) reduces the risk of VA, little is known about the prognostic value of VA among patients with CRT devices. OBJECTIVES: The purpose of this study was to evaluate the implications of VA as a prognostic marker for CRT. METHODS: We investigated 330 CRT patients within 1 year after CRT device implantation. The primary endpoint was the composite endpoint of all-cause death or hospitalization for heart failure. RESULTS: Forty-three patients had VA events. These patients had a significantly higher risk of the primary endpoint, even among CRT responders (P = .009). Fast VA compared to slow VA was associated with an increased risk of the primary endpoint (hazard ratio [HR] 2.14; 95% confidence interval [CI] 1.06-4.34; P = .035). Shock therapy was not associated with a primary endpoint (shock therapy vs antitachycardia pacing: HR 1.49; 95% CI 0.73-3.03; P = .269). The patients with VA had a lower prevalence of response to CRT (23 [53%] vs 202 [70%]; P = .031) and longer left ventricular paced conduction time (174 ± 23 ms vs 143 ± 36 ms; P = .003) than the patients without VA. CONCLUSION: VA occurrence within 1 year was related to paced electrical delay and poor response to CRT. VA could be associated with poor prognosis among CRT patients.

Clinical Significance of Atrial Tachyarrhythmia Duration for Ventricular Arrhythmia in Patients With Cardiac Resynchronization Therapy.

BACKGROUND: Atrial tachyarrhythmias (ATAs) are reportedly associated with ventricular arrhythmias (VAs). However, little is known about the association between ATA duration and the risk of VA. We investigated the relationship between ATA duration and subsequent VA in patients with a cardiac resynchronization therapy defibrillator (CRT-D).Methods and Results: We investigated associations between the longest ATA duration during the first year after cardiac resynchronization therapy (CRT) implantation and VA and VA relevant to ATA (VAATA) in 160 CRT-D patients. ATAs occurred in 63 patients in the first year. During a median follow-up of 925 days from 1 year after CRT implantation, 40 patients experienced 483 VAs. Kaplan-Meier analysis showed a significantly higher risk of VA in patients with than without ATA in the first year (log rank P=0.0057). Hazard ratios (HR) of VA (HR 2.36, 2.10, and 3.04 for ATA >30s, >6 min and >24 h, respectively) and only VAATA (HR 4.50, 5.59, and 11.79 for ATA >30s, >6 min and >24 h, respectively) increased according to the duration of ATA. In multivariate analysis, ATA >24 h was an independent predictor of subsequent VA (HR 2.42; P=0.02). CONCLUSIONS: Patients with ATA >24 h in the first year after CRT had a higher risk of subsequent VA and VAATA. The risk of VA, including VAATA, increased with the longest ATA duration.

Tenascin-C as a potential marker for immunohistopathology of doxorubicin-induced cardiomyopathy.

Aims: Doxorubicin is used in classical chemotherapy for several cancer types. Doxorubicin-induced cardiomyopathy (DOX-CM) is a critical issue among cancer patients. However, differentiating the diagnosis of DOX-CM from that of other cardiomyopathies is difficult. Therefore, in this study, we aimed to determine novel histopathological characteristics to diagnose DOX-CM. Methods and results: Twelve consecutive patients with DOX-CM who underwent cardiac histopathological examination in two medical centres were included. Twelve patients with dilated cardiomyopathy, who were matched with DOX-CM patients in terms of age, sex, and left ventricular ejection fraction, formed the control group. Another control group comprised five consecutive patients with cancer therapy-related cardiac dysfunction induced by tyrosine kinase inhibitors or vascular endothelial growth factor inhibitors were the controls. The positive area of tenascin-C, number of infiltrating macrophages, and presence of p62- and ubiquitin-positive cardiomyocytes were evaluated. Human-induced pluripotent stem cell-derived cardiomyocytes (hiPSC-CMs) were used for in vitro investigation. The myocardium exhibited significantly greater tenascin-C-positive area and macrophage number in the DOX-CM group than in the control groups (P < 0.01). The tenascin-C-positive area correlated with the number of both CD68- and CD163-positive cells (r = 0.748 and r = 0.656, respectively). Immunostaining for p62 was positive in 10 (83%) patients with DOX-CM. Furthermore, western blotting analysis revealed significant increase in tenascin-C levels in hiPSC-CMs upon doxorubicin treatment (P < 0.05). Conclusion: The combined histopathological assessment for tenascin-C, macrophages, and p62/ubiquitin may serve as a novel tool for the diagnosis of DOX-CM. Doxorubicin may directly affect the expression of tenascin-C in the myocardium.

Diagnosis of cardiac sarcoidosis: histological evidence vs. imaging.

INTRODUCTION: The prognosis for cardiac sarcoidosis (CS) remains unfavorable. Although early and accurate diagnosis is crucial, the low detection rate of endomyocardial biopsy makes accurate diagnosis challenging. AREAS COVERED: The Heart Rhythm Society (HRS) consensus statement and the Japanese Circulation Society (JCS) guidelines are two major diagnostic criteria for the diagnosis of CS. While the requirement of positive histology for the diagnosis in the HRS criteria can result in overlooked cases, the JCS guidelines advocate for a group of 'clinical' diagnoses based on advanced imaging, including cardiovascular magnetic resonance and 18F-fluorodeoxyglucose positron emission tomography, which do not require histological evidence. Recent studies have supported the usefulness of clinical diagnosis of CS. However, other evidence suggests that clinical CS may sometimes be inaccurate. This article describes the advantages and disadvantages of the current diagnostic criteria for CS, and typical imaging and clinical courses. EXPERT OPINION: The diagnosis of clinical CS has been made possible by recent developments in multimodality imaging. However, it is still crucial to look for histological signs of sarcoidosis in other organs in addition to the endomyocardium. Additionally, phenotyping based on clinical manifestations such as heart failure, conduction abnormality or ventricular arrhythmia, and extracardiac abnormalities is clinically significant.

Efficacy of azilsartan on left ventricular diastolic dysfunction compared with candesartan: J-TASTE randomized controlled trial.

Characterized by ventricular and vascular stiffness, heart failure with preserved ejection fraction (HFpEF) has led to high morbidity and mortality. As azilsartan is an angiotensin receptor blocker with the highest myocardial and vascular affinities, azilsartan may improve the left ventricular (LV) diastolic function in patients with hypertension and either HFpEF or HF with mildly reduced ejection fraction (HFmrEF) more than candesartan. In this randomized, open-label trial, we randomly assigned 193 hypertensive patients with HF and LV ejection fraction ≥ 45% to 20 mg of azilsartan (n = 95) or 8 mg of candesartan (n = 98), once daily for 48 weeks. After the initiation of treatment, changes in the doses of the study drugs were permitted based on the patient's conditions, including blood pressure (median dose at 48 weeks: azilsartan 20.0 mg/day, candesartan 8.0 mg/day). The primary endpoint was the baseline-adjusted change in the ratio of peak early diastolic transmitral flow velocity (E) to early diastolic mitral annular velocity (e') (E/e'). Adjusted least-squares mean (LSM) change in E/e' was - 0.8 (95% confidence interval [CI] - 1.49 to - 0.04) in the azilsartan group and 0.2 (95% CI - 0.49 to 0.94) in the candesartan group, providing the LSM differences of - 1.0 (95% CI - 2.01 to 0.03, P = 0.057). The median change in left atrial volume index was - 2.7 mL/m2 with azilsartan vs 1.4 mL/m2 with candesartan (P = 0.091). The frequency of adverse events related to hypotension and hyperkalemia did not differ between the groups. The current study did not provide strong evidence that azilsartan improves LV diastolic dysfunction, and further confirmatory study is required.

Cardiac Reversibility and Survival After Transcatheter Aortic Valve Implantation in Patients With Low-Gradient Aortic Stenosis.

Background Prognostic implications of transcatheter aortic valve implantation (TAVI) in low-gradient (LG) aortic stenosis (AS) remain controversial. The authors hypothesized that differences in cardiac functional recovery may solve this ongoing controversy. The aim was to evaluate clinical outcomes and the response of left ventricular (LV) function following TAVI in patients with LG AS. Methods and Results This multicenter retrospective study included 1742 patients with severe AS undergoing TAVI between January 2015 and March 2019. Patients were subdivided into low-flow (LF) LG, normal-flow (NF) LG, LF high-gradient, and NF high-gradient AS groups according to the mean gradient of the aortic valve (LG <40 mm Hg) and LV stroke volume index (LF <35 mL/m2). Outcomes and changes in echocardiographic parameters after TAVI were compared between the groups. A total of 227 patients (13%) had reduced ejection fraction, and 486 patients (28%) had LG AS (LF-LG 143 [8%]; NF-LG 343 [20%]). During a median follow-up period of 747 days, 301 patients experienced a composite end point of cardiovascular death and rehospitalization for cardiovascular events, which was higher in the LF-LG and NF-LG groups than in the high-gradient groups. LG AS was independently associated with the primary outcome (hazard ratio, 1.69; P<0.001). Among 1239 patients with follow-up echocardiography, LG AS showed less improvement in the LV mass index and LV end-diastolic volume compared with high-gradient AS after 1 year, while LV recovery was similar between the LF AS and NF AS groups. Conclusions LG AS was associated with poorer outcomes and LV recovery, regardless of flow status after TAVI. Careful evaluation of AS severity may be required in LG AS to provide TAVI within the appropriate time and advanced care afterward.