Regurgitant Volume to LA Volume Ratio in Patients with Secondary MR: The COAPT Trial.

AIMS: The conceptual framework of proportionate versus disproportionate mitral regurgitation (MR) translates poorly to individual patients with heart failure (HF) and secondary MR. A novel index, the ratio of MR severity to left atrial volume (LAV), may identify patients with "disproportionate" MR and a higher risk of events. The objectives, therefore, were to investigate the prognostic impact of MR severity to LAV ratio on outcomes among HF patients with severe secondary MR randomized to transcatheter edge-to-edge repair (TEER) with the MitraClipTM device plus guideline-directed medical therapy (GDMT) vs. GDMT alone in the COAPT trial. METHODS AND RESULTS: The ratio of preprocedural regurgitant volume (RVol) to LAV was calculated from baseline transthoracic echocardiograms. The primary endpoint was 2-year covariate-adjusted rate of HF hospitalization (HFH).Among 567 patients, the median RVol/LAV was 0.67 (IQR 0.48-0.91). In patients randomized to GDMT alone, lower RVol/LAV was independently associated with an increased 2-year risk of HFH (adjHR: 1.77; 95% CI: 1.20-2.63). RVol/LAV was a stronger predictor of adverse outcomes than RVol or LAV alone. Treatment with TEER plus GDMT compared with GDMT alone was associated with lower 2-year rates of HFH both in patients with low and high RVol/LAV (Pinteraction = 0.28). Baseline RVol/LAV ratio was unrelated to 2-year mortality, health status, or functional capacity in either treatment group. CONCLUSIONS: Low RVol/LAV ratio was an independent predictor of 2-year HFH in HF patients with severe MR treated with GDMT alone in the COAPT trial. TEER improved outcomes regardless of baseline RVol/LAV ratio. CLINICAL TRIAL REGISTRATION: Trial Name: Cardiovascular Outcomes Assessment of the MitraClip Percutaneous Therapy for Heart Failure Patients With Functional Mitral Regurgitation (The COAPT Trial) (COAPT) ClinicalTrial.gov Identifier: NCT01626079 URL: https://clinicaltrials.gov/ct2/show/NCT01626079.

Incidence, Predictors, and Outcomes Associated With Worsening Renal Function in Patients With Heart Failure and Secondary Mitral Regurgitation: The COAPT Trial.

Background The incidence and implications of worsening renal function (WRF) after mitral valve transcatheter edge-to-edge repair (TEER) in patients with heart failure (HF) are unknown. Therefore, the aim of this study was to determine the proportion of patients with HF and secondary mitral regurgitation who develop persistent WRF within 30 days following TEER, and whether this development portends a worse prognosis. Methods and Results In the COAPT (Cardiovascular Outcomes Assessment of the MitraClip Percutaneous Therapy for Heart Failure Patients With Functional Mitral Regurgitation) trial, 614 patients with HF and severe secondary mitral regurgitation were randomized to TEER with the MitraClip plus guideline-directed medical therapy (GDMT) versus GDMT alone. WRF was defined as serum creatinine increase ≥1.5× or ≥0.3 mg/dL from baseline persisting to day 30 or requiring renal replacement therapy. All-cause death and HF hospitalization rates between 30 days and 2 years were compared in patients with and without WRF. WRF at 30 days was present in 11.3% of patients (9.7% in the TEER plus GDMT group and 13.1% in the GDMT alone group; P=0.23). WRF was associated with all-cause death (hazard ratio [HR], 1.98 [95% CI, 1.3-3.03]; P=0.001) but not HF hospitalization (HR, 1.47 [ 95% CI, 0.97-2.24]; P=0.07) between 30 days and 2 years. Compared with GDMT alone, TEER reduced both death and HF hospitalization consistently in patients with and without WRF (Pinteraction=0.53 and 0.57, respectively). Conclusions Among patients with HF and severe secondary mitral regurgitation, the incidence of WRF at 30 days was not increased after TEER compared with GDMT alone. WRF was associated with greater 2-year mortality but did not attenuate the treatment benefits of TEER in reducing death and HF hospitalization compared with GDMT alone. Registration URL: https://www.clinicaltrials.gov; Unique identifier: NCT01626079.

Cerebrovascular Events After Transcatheter Edge-to-Edge Repair and Guideline-Directed Medical Therapy in the COAPT Trial.

BACKGROUND: Little is known regarding the risk of cerebrovascular events (CVE) in patients with heart failure and severe secondary mitral regurgitation treated with transcatheter edge-to-edge repair (TEER). OBJECTIVES: The study sought to examine the incidence, predictors, timing, and prognostic impact of CVE (stroke or transient ischemic attack) in the COAPT (Cardiovascular Outcomes Assessment of the Mitraclip Percutaneous Therapy for Heart Failure Patients with Functional Mitral Regurgitation) trial. METHODS: A total of 614 patients with heart failure and severe secondary mitral regurgitation were randomized to TEER plus guideline-directed medical therapy (GDMT) vs GDMT alone. RESULTS: At 4-year follow-up, 50 CVEs occurred in 48 (7.8%) of the 614 total patients enrolled in the COAPT trial; Kaplan-Meier event rates were 12.3% in the TEER group and 10.2 in the GDMT alone group (P = 0.91). Within 30 days of randomization, CVE occurred in 2 (0.7%) patients randomized to TEER and 0% randomized to GDMT (P = 0.15). Baseline renal dysfunction and diabetes were independently associated with increased risk of CVE, while baseline anticoagulation was associated with a reduction of CVE. A significant interaction was present between treatment group and anticoagulation such that TEER compared with GDMT alone was associated with a reduced risk of CVE among patients with anticoagulation (adjusted HR: 0.24; 95% CI: 0.08-0.73) compared with an increased risk of CVE in patients without anticoagulation (adjusted HR: 2.27; 95% CI: 1.08-4.81; Pinteraction = 0.001). CVE was an independent predictor of death within 30 days after the event (HR: 14.37; 95% CI: 7.61, 27.14; P < 0.0001). CONCLUSIONS: In the COAPT trial, the 4-year rate of CVE was similar after TEER or GDMT alone. CVE was strongly associated with mortality. Whether anticoagulation is effective at reducing CVE risk after TEER warrants further study. (Cardiovascular Outcomes Assessment of the MitraClip Percutaneous Therapy for Heart Failure Patients With Functional Mitral Regurgitation [The COAPT Trial] and COAPT CAS [COAPT); NCT01626079).

Utility of the ACC/AHA Lesion Classification to Predict Outcomes After Contemporary DES Treatment: Individual Patient Data Pooled Analysis From 7 Randomized Trials.

Background Use of the modified American College of Cardiology (ACC)/American Heart Association (AHA) lesion classification as a prognostic tool to predict short- and long-term clinical outcomes after percutaneous coronary intervention in the modern drug-eluting stent era is uncertain. Methods and Results Patient-level data from 7 prospective, randomized trials were pooled. Clinical outcomes of patients undergoing single lesion percutaneous coronary intervention with second-generation drug-eluting stent were analyzed according to modified ACC/AHA lesion class. The primary end point was target lesion failure (TLF: composite of cardiac death, target vessel myocardial infarction, or ischemia-driven target lesion revascularization). Clinical outcomes to 5 years were compared between patients treated for noncomplex (class A/B1) versus complex (class B2/C) lesions. Eight thousand five hundred sixteen patients (age 63.1±10.8 years, 70.5% male) were analyzed. Lesions were classified as A, B1, B2, and C in 7.9%, 28.5%, 33.7%, and 30.0% of cases, respectively. Target lesion failure was higher in patients undergoing percutaneous coronary intervention of complex versus noncomplex lesions at 30 days (2.0% versus 1.1%, P=0.004), at 1 year (4.6% versus 3.0%, P=0.0005), and at 5 years (12.4% versus 9.2%, P=0.0001). By multivariable analysis, treatment of ACC/AHA class B2/C lesions was significantly associated with higher rate of 5-year target lesion failure (adjusted hazard ratio, 1.39 [95% CI, 1.17-1.64], P=0.0001) driven by significantly higher rates of target vessel myocardial infarction and ischemia-driven target lesion revascularization. Conclusions In this pooled large-scale analysis, treating complex compared with noncomplex lesions according to the modified ACC/AHA classification with second-generation drug-eluting stent was associated with worse 5-year clinical outcomes. This historical classification system may be useful in the contemporary era for predicting early and late outcomes following percutaneous coronary intervention.

Impact of Nonobstructive Left Main Coronary Artery Atherosclerosis on Long-Term Mortality.

BACKGROUND: Although the presence of severe stenosis in the left main coronary artery (LMCA) is a well-established predictor of mortality, whether this extends to nonobstructive atherosclerosis in the LMCA is unknown. OBJECTIVES: The aim of this study was to evaluate the association between LMCA disease by intravascular ultrasound (IVUS) and long-term mortality. METHODS: Between 2005 and 2013, 3,239 patients with LMCA IVUS imaging without LMCA revascularization (either before angiography or scheduled based on index angiography or IVUS) were included. The primary and secondary endpoints were all-cause and cardiac mortality at a minimum of 5 years obtained from the National Death Index. RESULTS: The IVUS-measured LMCA minimum lumen area (MLA) and plaque burden were 13.1 ± 5.0 mm2 and 41.7% ± 15.6%, respectively. The median follow-up was 8.2 years. The Kaplan-Meier estimated 12-year all-cause and cardiac death rates were 37.5% and 17.0%, respectively. Greater plaque burden (unadjusted HR per 10%: 1.17; 95% CI: 1.12-1.22; P < 0.0001) and smaller IVUS MLA (unadjusted HR per 1 mm2: 0.98; 95% CI: 0.96-0.99; P = 0.0008) were associated with all-cause death. After adjusting for clinical, angiographic, and IVUS factors, plaque burden (adjusted HR per 10%: 1.12; 95% CI: 1.04-1.21; P = 0.003) but not MLA (adjusted HR per 1 mm2: 1.02; 95% CI: 0.99-1.04; P = 0.18) was associated with long-term all-cause death. These findings were also consistent for long-term cardiac mortality. CONCLUSIONS: In the present large-scale study with a 12-year follow-up, increasing LMCA plaque burden was associated with long-term all-cause and cardiac mortality in patients not undergoing LMCA revascularization, even when the lumen area was preserved.

Impact of baseline renal dysfunction on cardiac outcomes and end-stage renal disease in heart failure patients with mitral regurgitation: the COAPT trial.

AIMS: Baseline renal dysfunction (RD) adversely impacts outcomes among patients with heart failure (HF) and severe secondary mitral regurgitation (MR). Heart failure and MR, in turn, accelerate progression to end-stage renal disease (ESRD), worsening prognosis. We sought to determine the impact of RD in HF patients with severe MR and the impact of transcatheter mitral valve repair (TMVr) on new-onset ESRD and the need for renal replacement therapy (RRT). METHODS AND RESULTS: The COAPT trial randomized 614 patients with HF and severe MR to MitraClip plus guideline-directed medical therapy (GDMT) vs. GDMT alone. Patients were stratified into three RD subgroups based on baseline estimated glomerular filtration rate (eGFR, mL/min/1.73 m2): none (≥60), moderate (30-60), and severe (<30). End-stage renal disease was defined as eGFR <15 mL/min/1.73 m2 or RRT. The 2-year rates of all-cause death or HF hospitalization (HFH), new-onset ESRD, and RRT according to RD and treatment were assessed. Baseline RD was present in 77.0% of patients, including 23.8% severe RD, 6.0% ESRD, and 5.2% RRT. Worse RD was associated with greater 2-year risk of death or HFH (none 45.3%; moderate 53.9%; severe 69.2%; P < 0.0001). MitraClip vs. GDMT alone improved outcomes regardless of RD (Pinteraction = 0.62) and reduced new-onset ESRD [2.9 vs. 8.1%, hazard ratio (HR) 0.34, 95% confidence interval (CI) 0.15-0.76, P = 0.008] and the need for new RRT (2.5 vs. 7.4%, HR 0.33, 95% CI 0.14-0.78, P = 0.011). CONCLUSION: Baseline RD was common in the HF patients with severe MR enrolled in COAPT and strongly predicted 2-year death and HFH. MitraClip treatment reduced new-onset ESRD and the need for RRT, contributing to the improved prognosis after TMVr.

Age-Related Outcomes After Transcatheter Mitral Valve Repair in Patients With Heart Failure: Analysis From COAPT.

OBJECTIVES: The aim of this study was to assess the impact of age on outcomes in patients undergoing transcatheter edge-to-edge repair (TEER) from the COAPT (Cardiovascular Outcomes Assessment of the MitraClip Percutaneous Therapy for Heart Failure Patients with Functional Mitral Regurgitation) trial. BACKGROUND: In the COAPT trial, TEER with the MitraClip device in patients with heart failure (HF) and moderate to severe or severe secondary mitral regurgitation (SMR) reduced the risk for HF hospitalization (HFH) and all-cause mortality compared with maximally tolerated guideline-directed medical therapy (GDMT) alone. There are limited data regarding the effectiveness of MitraClip therapy in elderly patients. METHODS: Patients (n = 614) were grouped by median age at randomization (74 years) and by MitraClip treatment vs GDMT alone. The primary endpoint was the 2-year rate of death or HFH assessed by multivariable Cox regression. RESULTS: Death or HFH within 2 years occurred less frequently after treatment with the MitraClip vs GDMT alone in patients <74 years of age (37.3% vs 64.5%; adjusted HR: 0.41; 95% CI: 0.29-0.59) and ≥74 years of age (51.7% vs 69.6%; adjusted HR: 0.58; 95% CI: 0.42-0.81) (Pint = 0.17). Mortality was also consistently reduced with MitraClip treatment in young and elderly patients (Pint = 0.42). In contrast, elderly patients treated with the MitraClip vs GDMT alone tended to have a lesser reduction of HFH than younger patients (Pint = 0.03). Younger and older patients had similar improvements in quality of life after treatment with the MitraClip compared with GDMT alone. CONCLUSIONS: In the COAPT trial, MitraClip treatment of moderate to severe and severe SMR reduced the composite risk for death or HFH and improved survival and quality of life regardless of age. As such, young and elderly patients with HF and severe SMR benefit from TEER, although elderly patients may not have as great a benefit from the MitraClip device in reducing HFH.

Risk-Benefit of 1-Year DAPT After DES Implantation in Patients Stratified by Bleeding and Ischemic Risk.

BACKGROUND: Although a 1-year duration of dual antiplatelet therapy (DAPT) is used in many patients after drug-eluting stent (DES) implantation, the evidence supporting this duration is uncertain. OBJECTIVES: The authors investigated the risk-benefit profile of 1-year vs ≤6-month DAPT after DES using 2 novel scores to risk stratify bleeding and ischemic events. METHODS: Ischemic and bleeding risk scores were generated from ADAPT-DES (Assessment of Dual Antiplatelet Therapy With Drug-Eluting Stents), a multicenter, international, "all-comers" registry that enrolled 8,665 patients treated with DES. The risk-benefit profile of 1-year vs ≤6-month DAPT was then investigated across risk strata from an individual patient data pooled dataset of 7 randomized trials that enrolled 15,083 patients treated with DES. RESULTS: In the derivation cohort, the ischemic score and the bleeding score had c-indexes of 0.76 and 0.66, respectively, and both were well calibrated. In the pooled dataset, no significant difference was apparent in any ischemic endpoint between 1-year and ≤6-month DAPT, regardless of the risk strata. In the overall dataset, there was no significant difference in the risk of clinically relevant bleeding between 1-year and ≤6-month DAPT; however, among 2,508 patients at increased risk of bleeding, 1-year compared with ≤6-month DAPT was associated with greater bleeding (HR: 2.80; 95% CI: 1.12-7.13) without a reduced risk of ischemic events in any risk strata, including those with acute coronary syndromes. These results were consistent in a network meta-analysis. CONCLUSIONS: In the present large-scale study, compared with ≤6-month DAPT, a 1-year duration of DAPT was not associated with reduced adverse ischemic events in any risk strata (including acute coronary syndromes) but was associated with greater bleeding in patients at increased risk of bleeding.

Risk-Benefit of 1-Year DAPT After DES Implantation in Patients Stratified by Bleeding and Ischemic Risk

BACKGROUND: Although a 1-year duration of dual antiplatelet therapy (DAPT) is used in many patients after drug-eluting stent (DES) implantation, the evidence supporting this duration is uncertain. OBJECTIVES: The authors investigated the risk-benefit profile of 1-year vs ≤6-month DAPT after DES using 2 novel scores to risk stratify bleeding and ischemic events. METHODS: Ischemic and bleeding risk scores were generated from ADAPT-DES (Assessment of Dual Antiplatelet Therapy with Drug-Eluting Stents), a multicenter, international, "all-comers" registry that enrolled 8,665 patients treated with DES. The risk-benefit profile of 1-year vs ≤6-month DAPT was then investigated across risk strata from an individual patient data pooled dataset of 7 randomized trials that enrolled 15,083 patients treated with DES. RESULTS: In the derivation cohort, the ischemic score and the bleeding score had c-indexes of 0.76 and 0.66, respectively, and both were well calibrated. In the pooled dataset, no significant difference was apparent in any ischemic endpoint between 1-year and ≤6-month DAPT, regardless of the risk strata. In the overall dataset, there was no significant difference in the risk of clinically relevant bleeding between 1-year and ≤6-month DAPT; however, among 2,508 patients at increased risk of bleeding, 1-year compared with ≤6-month DAPT was associated with greater bleeding (HR: 2.80; 95% CI: 1.12-7.13) without a reduced risk of ischemic events in any risk strata, including those with acute coronary syndromes. These results were consistent in a network meta-analysis. CONCLUSIONS: In the present large-scale study, compared with ≤6-month DAPT, a 1-year duration of DAPT was not associated with reduced adverse ischemic events in any risk strata (including acute coronary syndromes) but was associated with greater bleeding in patients at increased risk of bleeding.

Impact of COPD on Outcomes After MitraClip for Secondary Mitral Regurgitation: The COAPT Trial.

OBJECTIVES: The aim of this study was to examine the relationship between chronic obstructive pulmonary disease (COPD) and outcomes after transcatheter mitral valve repair (TMVr) for severe secondary mitral regurgitation. BACKGROUND: TMVr with the MitraClip improves clinical and health-status outcomes in patients with heart failure and severe (3+ to 4+) secondary mitral regurgitation. Whether these benefits are modified by COPD is unknown. METHODS: COAPT (Cardiovascular Outcomes Assessment of the MitraClip Percutaneous Therapy for Heart Failure Patients With Functional Mitral Regurgitation) was an open-label, multicenter, randomized trial of TMVr plus guideline-directed medical therapy (GDMT) versus GDMT alone. Patients on corticosteroids or continuous oxygen were excluded. Multivariable models were used to examine the associations of COPD with mortality, heart failure hospitalization (HFH), and health status and to test whether COPD modified the benefit of TMVr compared with GDMT. RESULTS: Among 614 patients, 143 (23.2%) had COPD. Among patients treated with TMVr, unadjusted analyses demonstrated increased 2-year mortality in those with COPD (hazard ratio [HR]: 2.08; 95% confidence interval [CI]: 1.33 to 3.26), but this association was attenuated after risk adjustment (adjusted HR: 1.48; 95% CI: 0.87 to 2.52). Although TMVr led to reduced 2-year mortality among patients without COPD (adjusted HR: 0.47; 95% CI: 0.33 to 0.67), for patients with COPD, 2-year all-cause mortality was similar after TMVr versus GDMT alone (adjusted HR: 0.94; 95% CI: 0.54 to 1.65; pint = 0.04), findings that reflect offsetting effects on cardiovascular and noncardiovascular mortality. In contrast, TMVr reduced HFH (adjusted HR: 0.48 [95% CI: 0.28 to 0.83] vs. 0.46 [95% CI: 0.34 to 0.63]; pint = 0.89) and improved both generic and disease-specific health status to a similar extent compared with GDMT alone in patients with and without COPD (pint >0.30 for all scales). CONCLUSIONS: In the COAPT trial, COPD was associated with attenuation of the survival benefit of TMVr versus GDMT compared with patients without COPD. However, the benefits of TMVr on both HFH and health status were similar regardless of COPD. (Cardiovascular Outcomes Assessment of the MitraClip Percutaneous Therapy for Heart Failure Patients With Functional Mitral Regurgitation [The COAPT Trial] [COAPT]; NCT01626079).

NYHA Functional Classification and Outcomes After Transcatheter Mitral Valve Repair in Heart Failure: The COAPT Trial.

OBJECTIVES: The aim of this study was to evaluate the outcomes of MitraClip implantation versus guideline-directed medical therapy (GDMT) in patients with secondary mitral regurgitation (SMR) according to baseline functional status as assessed by the widely used New York Heart Association (NYHA) functional classification. BACKGROUND: Patients with heart failure (HF) and impaired functional status at baseline have poor prognosis. Whether the effects of transcatheter repair of secondary SMR in patients with HF are influenced by baseline functional status is unknown. METHODS: In the COAPT (Cardiovascular Outcomes Assessment of the MitraClip Percutaneous Therapy for Heart Failure Patients with Functional Mitral Regurgitation) trial, patients with HF with moderate to severe or severe SMR who remained symptomatic despite maximally tolerated GDMT were randomized to MitraClip implantation versus GDMT alone. Outcomes were evaluated according to baseline functional status as assessed using the NYHA functional classification. The primary endpoint of interest was the rate of death or HF-related hospitalization (HFH) at 2 years in time-to-first-event analyses. RESULTS: Among 613 randomized patients, 240 were in NYHA functional class II (39.2%), 322 were in NYHA functional class III (52.5%), and 51 were in ambulatory NYHA functional class IV (8.3%). Rates of death or HFH were progressively higher with increasing NYHA functional class. Compared with GDMT alone, MitraClip implantation resulted in lower 2-year rates of death or HFH consistently in patients in NYHA functional class II (39.7% vs. 63.7%; hazard ratio [HR]: 0.54; 95% confidence interval [CI]: 0.37 to 0.77), NYHA functional class III (46.6% vs. 65.5%; HR: 0.60; 95% CI: 0.45 to 0.82), and NYHA functional class IV (66.7% vs. 85.2%; HR: 0.55; 95% CI: 0.28 to 1.10; pinteraction = 0.86). Greater improvements in quality of life at 2 years were observed in patients treated with the MitraClip compared with GDMT irrespective of baseline functional status. CONCLUSIONS: The NYHA functional classification provides prognostic utility in patients with HF and moderate to severe or severe SMR. In the COAPT trial, the benefits of MitraClip implantation were consistent in patients with better or worse functional status as assessed by NYHA functional class. (Cardiovascular Outcomes Assessment of the MitraClip Percutaneous Therapy for Heart Failure Patients With Functional Mitral Regurgitation [The COAPT Trial] [COAPT]; NCT01626079).

Baseline Functional Capacity and Transcatheter Mitral Valve Repair in Heart Failure With Secondary Mitral Regurgitation.

OBJECTIVES: The aim of this study was to determine the prognostic utility of baseline functional status and its impact on the outcomes of transcatheter mitral valve repair (TMVr) in patients with heart failure (HF) with secondary mitral regurgitation (SMR). BACKGROUND: The COAPT (Cardiovascular Outcomes Assessment of the MitraClip Percutaneous Therapy for Heart Failure Patients With Functional Mitral Regurgitation) trial demonstrated that TMVr with the MitraClip in patients with HF with moderate to severe or severe SMR improved health-related quality of life. The clinical utility of a baseline assessment of functional status for evaluating prognosis and identifying candidates likely to derive a robust benefit from TMVr has not been previously studied in patients with HF with SMR. METHODS: The COAPT study was a multicenter, randomized, controlled, parallel-group, open-label trial of TMVr with the MitraClip plus guideline-directed medical therapy (GDMT) versus GDMT alone in patients with HF, left ventricular ejection fraction 20% to 50%, and moderate to severe or severe SMR. Baseline functional status was assessed by 6-min walk distance (6MWD). RESULTS: Patients with 6MWD less than the median (240 m) were older, were more likely to be female, and had more comorbidities. After multivariate modeling, age (p = 0.005), baseline hemoglobin (p = 0.007), and New York Heart Association functional class III/IV symptoms (p < 0.0001) were independent clinical predictors of 6MWD. Patients with 6MWD <240 m versus ≥240 m had a higher unadjusted and adjusted rate of the 2-year composite of all-cause death or HF hospitalization (64.4% vs. 48.6%; adjusted hazard ratio: 1.53; 95% confidence interval: 1.19 to 1.98; p = 0.001). However, there was no interaction between baseline 6MWD and the relative effectiveness of TMVr plus GDMT versus GDMT alone with respect to the composite endpoint (p = 0.633). CONCLUSIONS: Baseline assessment of functional capacity by 6MWD was a powerful discriminator of prognosis in patients with HF with SMR. TMVr with the MitraClip provided substantial improvements in clinical outcomes for this population irrespective of baseline functional capacity.

Predictors of Clinical Response to Transcatheter Reduction of Secondary Mitral Regurgitation: The COAPT Trial.

BACKGROUND: Transcatheter mitral valve repair with the MitraClip results in marked clinical improvement in some but not all patients with secondary mitral regurgitation (MR) and heart failure (HF). OBJECTIVES: This study sought to evaluate the clinical predictors of a major response to treatment in the COAPT trial. METHODS: Patients with HF and severe MR who were symptomatic on maximally tolerated guideline-directed medical therapy (GDMT) were randomly assigned to MitraClip plus GDMT or GDMT alone. Super-responders were defined as those alive without HF hospitalization and with ≥20-point improvement in the Kansas City Cardiomyopathy Questionnaire overall summary (KCCQ-OS) score at 12 months. Responders were defined as those alive without HF hospitalization and with a 5 to <20-point KCCQ-OS improvement at 12 months. Nonresponders were those who either died, were hospitalized for HF, or had <5-point improvement in KCCQ-OS at 12 months. RESULTS: Among 614 enrolled patients, 41 (6.7%) had missing KCCQ-OS data and could not be classified. At 12 months, there were 79 super-responders (27.2%), 55 responders (19.0%), and 156 nonresponders (53.8%) in the MitraClip arm compared with 29 super-responders (10.2%), 46 responders (16.3%), and 208 nonresponders (73.5%) in the GDMT-alone arm (overall p < 0.0001). Independent baseline predictors of clinical responder status were lower serum creatinine and KCCQ-OS scores and treatment assignment to MitraClip. MR grade and estimated right ventricular systolic pressure at 30 days were improved to a greater degree in super-responders and responders but not in nonresponders. CONCLUSIONS: Baseline predictors of clinical super-responders in patients with HF and severe secondary MR in the COAPT trial were lower serum creatinine, KCCQ-OS score and MitraClip treatment. Improved MR severity and reduced right ventricular systolic pressure at 30 days are associated with a long-term favorable clinical response after transcatheter mitral valve repair. (Cardiovascular Outcomes Assessment of the MitraClip Percutaneous Therapy for Heart Failure Patients With Functional Mitral Regurgitation [COAPT]; NCT01626079).

A segmented measurement error model for modeling and analysis of method comparison data.

Method comparison studies are concerned with estimating relationship between two clinical measurement methods. The methods often exhibit a structural change in the relationship over the measurement range. Ignoring this change would lead to an inaccurate estimate of the relationship. Motivated by a study of two digoxin assays where such a change occurs, this article develops a statistical methodology for appropriately analyzing such studies. Specifically, it proposes a segmented extension of the classical measurement error model to allow a piecewise linear relationship between the methods. The changepoint at which the transition takes place is treated as an unknown parameter in the model. An expectation-maximization-type algorithm is developed to fit the model and appropriate extensions of the existing measures are proposed for segment-specific evaluation of similarity and agreement. Bootstrapping and large-sample theory of maximum likelihood estimators are employed to perform the relevant inferences. The proposed methodology is evaluated by simulation and is illustrated by analyzing the digoxin data.