Afterload Mismatch After MitraClip Implantation: The Potential Impact of Pharmacologic Support

In-hospital complications after MitraClip in patients with heart failure and preserved versus reduced ejection fraction in the United States

BACKGROUND

The clinical benefits of transcatheter edge to edge mitral valve repair have been well established in patients with heart failure and severe mitral regurgitation (MR) who have prohibitive surgical risk. In March of 2019, the FDA approved the MitraClip for treatment of selected patients with HF and severe secondary MR. However, the relative outcomes of patients with HFrEF and HFpEF treated with MitraClip are largely unknown. We therefore sought to investigate the incidence and characteristics of in-hospital mortality in patients with HFpEF and HFrEF following MitraClip.

METHODS

The study sample analyzed was originated from the National Inpatient Sample (NIS) registry which includes data from hospitalized patients in the United States (US) between January 1, 2012 and December 31, 2020. Data were extracted from the entire NIS registry using ICD-9 codes. Patients with the primary or secondary diagnosis of MitraClip were identified. Hospitalizations for HFpEF and HFrEF were identified based on ICD-9-CM and ICD-10-CM codes. Demographics, conventional risk factors, and in-hospital outcomes were evaluated.

RESULTS

23,260 hospitalizations for MitraClip implantation between 2016 and 2020 were analyzed. The HFrEF group had higher absolute rates of complications as well as a higher observed in-hospital mortality (2.4 % vs 1.7 %; OR 0.75 95 % CI 0.44-1.26; p 0.28) which did not meet statistical significance. Absolute rates of acute myocardial infarction (AMI), acute kidney injury (AKI) and respiratory failure necessitating invasive mechanical ventilation were observed to be higher among HFrEF patients. Post-procedural shock was significantly more common in patients with HFrEF (9.0 % vs 2.8 %: OR 0.34 95 % CI 0.25-0.48 p < 0.001). Significantly longer hospitalizations were observed in the HFrEF cohort (5.3 ± 11.2 days vs 4.2 ± 7.3 days; p < 0.001) as well as a higher total hospitalization cost (61,723 ± 56,728 USD vs 57,278 ± 46,143).

CONCLUSIONS

In the present study of US patients, those with HFrEF were observed to have statistically higher risk of in-hospital post-procedural shock and longer hospitalization length of stay when compared with patients with HFpEF who underwent MitraClip implantation. Additionally, patients with HFrEF undergoing MitraClip procedure were observed to have higher absolute rates of certain post-procedural complications, however these observations did not reach statistical significance. Understanding of the aforementioned differences after MitraClip implantation may be useful in-patient selection, prognostic guidance, and hypothesis generation to propel future large clinical studies.

Impact of Post-Procedural Change in Left Ventricle Systolic Function on Survival after Percutaneous Edge-to-Edge Mitral Valve Repair

OBJECTIVES

To investigate how the changes of left ventricle ejection fraction (LVEF) between admission and discharge affected the long-term outcome in patients who underwent percutaneous edge-to-edge mitral valve repair for secondary mitral regurgitation.

BACKGROUND

An acute impairment of LVEF after surgical repair of mitral regurgitation, known as afterload mismatch, has been associated with increased all-cause mortality. Afterload mismatch after percutaneous edge-to-edge mitral valve repair has been postulated to be a transient phenomenon.

METHODS

This study is based on a single-center, retrospective, observational registry of patients who underwent percutaneous edge-to-edge mitral valve repair with the MitraClip (Abbot Vascular) system for the treatment of symptomatic, moderate-to-severe mitral regurgitation. We included data on 399 patients who underwent percutaneous edge-to-edge mitral valve repair for secondary mitral regurgitation. Expert echocardiographers assessed LVEF before the procedure and at discharge. The patients were divided into three groups according to the difference of periprocedural LVEF measurements: unchanged (n = 318), improved (n = 40), and decreased (n = 41) LVEF.

RESULTS

The median follow-up time was 2.0 years. When adjusted for gender, NYHA class and estimated glomerular filtration rate, decreased postprocedural LVEF was associated with an increased risk of death (adjusted HR 2.05, 95% CI 1.26-3.34) and increased postprocedural LVEF with a reduced risk of death (adjusted HR 0.47, 95% CI 0.24-0.91) compared to unchanged LVEF. Conclusion: Among patients who underwent percutaneous edge-to-edge mitral valve repair, decreased postprocedural LVEF was associated with increased mortality, while improved LVEF was associated with lower mortality compared to unchanged LVEF.

Aggressive treatment of afterload mismatch to address left ventricular dysfunction after mitral valve repair: A case report

Mitral regurgitation (MR), one of the most common valvulopathies, occurs in at least 10% of the individuals older than 75 years. The long-standing volume overload occurring in severe MR inevitably leads to left ventricular (LV) enlargement and dysfunction; untreated, severe MR can progress to heart failure and death. Hypotension following separation from cardiopulmonary bypass after mitral valve intervention should alert an anesthesiologist to consider a myriad of differential diagnoses. This includes, but is not limited to, afterload mismatch, which can contribute to severe LV dysfunction, even in patients with seemingly normal preoperative ejection fraction. We present a case of acute on chronic biventricular failure after mitral valve repair due to afterload mismatch and discuss its management intraoperatively. Admittedly, identifying the causes of hypotension to guide treatment after mitral valve surgery in patients with severe MR is challenging. High index of suspicion and transesophageal echocardiogram guidance are important for prompt diagnosis, increasing the likelihood of successful outcomes with appropriate clinical management.

Percutaneous left ventricular advanced support for 'protected' complex high-risk transcatheter mitral valve repair: a case series

Background

Currently, the use of advanced ventricular support systems during percutaneous mitral valve repair (PMVR) procedures is confined to very few selected cases in emergency or bailout situations. No cases are reported of planned use of ventricular support devices in the subgroup of high-risk patients undergoing PMVR.

Case summary

We report two cases of planned and ‘protected’ procedures of PMVR with Impella CP mechanical circulatory support. No procedure-related complications occurred. At 6-month clinical follow-up evaluation, an improvement of symptoms and functional class (New York Heart Association) was reported.

Discussion

In the two cases reported, PMVR with Impella CP assistance was feasible, safe and effective in the setting of severe mitral regurgitation associated with dilated and severe left ventricular dysfunction. Extending the concept of ‘complex high-risk and indicated patients/procedures’ (CHIP) from the environment of coronary intervention, a ‘protected’ approach could lead to improve technical feasibility and clinical outcome in structural interventions, as advocated for ‘protected-percutaneous coronary intervention’.

Effect of Levosimendan on Renal Outcome in Cardiac Surgery Patients With Chronic Kidney Disease and Perioperative Cardiovascular Dysfunction: A Substudy of a Multicenter Randomized Trial

OBJECTIVE

Acute kidney injury (AKI) occurs frequently after cardiac surgery. Levosimendan might reduce the incidence of AKI in patients undergoing cardiac surgery. The authors investigated whether levosimendan administration could reduce AKI incidence in a high-risk cardiac surgical population.

DESIGN

Post hoc analysis of a multicenter randomized trial.

SETTING

Cardiac surgery operating rooms and intensive care units of 14 centers in 3 countries.

PARTICIPANTS

The study comprised 90 patients who underwent mitral valve surgery with an estimated glomerular filtration rate <60 mL/min/1.73 m² and perioperative myocardial dysfunction.

INTERVENTIONS

Patients were assigned randomly to receive levosimendan (0.025-0.2 μg/kg/min) or placebo in addition to standard inotropic treatment.

MEASUREMENTS AND MAIN RESULTS

Forty-six patients were assigned to receive levosimendan and 44 to receive placebo. Postoperative AKI occurred in 14 (30%) patients in the levosimendan group versus 23 (52%) in the placebo group (absolute difference -21.8; 95% confidence interval -41.7 to -1.97; p = 0.035). The incidence of major complications also was lower (18 [39%]) in the levosimendan group versus that in the placebo group (29 [66%]) (absolute difference -26.8 [-46.7 to -6.90]; p = 0.011). A trend toward lower serum creatinine at intensive care unit discharge was observed in the levosimendan group (1.18 [0.99-1.49] mg/dL) versus that in the placebo group (1.39 [1.05-1.76] mg/dL) (95% confidence interval -0.23 [-0.49 to 0.01]; p = 0.07).

CONCLUSIONS

Levosimendan may improve renal outcome in cardiac surgery patients with chronic kidney disease undergoing mitral valve surgery who develop perioperative myocardial dysfunction. Results of this exploratory analysis should be investigated in future properly designed randomized controlled trials.

Acute Hypotension After MitraClip Implantation due to Acute Left Ventricular Failure

The MitraClip is a percutaneously implanted device approved for the treatment of symptomatic organic mitral regurgitation in poor surgical candidates. Despite its proven efficacy and safety for mitral regurgitation treatment, the MitraClip may unmask the true afterload of the left ventricle by removing the low-pressure left atrial system and may cause acute left ventricular systolic failure (afterload mismatch). Rapid diagnosis and treatment of afterload mismatch is crucial to ensure optimal patient outcomes. The authors present a case of acute hemodynamic deterioration after MitraClip implantation in a patient with chronic severe left ventricular systolic dysfunction. Transesophageal echocardiography was pivotal for the rapid recognition of acute left ventricular failure and aided in the intraoperative decision-making process and therapy.