An observational, prospective study on surgical treatment of secondary mitral regurgitation: The SMR study. Rationale, purposes, and protocol

The natural history of secondary mitral regurgitation (MR) is unfavorable. Nevertheless, there are no evidence that its correction can improve the outcome. If from one side the original cause of secondary MR can be such to limit the possibilities of improvement, from the other side it is possible that the surgical technique widely applied to repair, restrictive mitral annuloplasty, is not adequate to correct the regurgitation. The addition of valvular and/or subvalvular techniques has been considered a possible technical solution. However, we do not know the prevalence of each technique, how many times mitral replacement is used to correct secondary MR. This aspect is of particular importance, as we know that a successful mitral repair causes a better left ventricular systolic remodeling than a unsuccessful repair or replacement. This study is a prospective, observational registry, conceived to understand what is done in the real world. Any surgeon will use the technique he thinks the most suitable for the patient. Every year, for 5 years, patients will have a clinical and echocardiographic follow-up, to evaluate the risk factors for a worse result (death, rehospitalization for heart failure, reoperation for MR return, moderate, or more MR return). This knowledge will give us the possibility to understand which is the technique, or the strategy, more efficient to treat this disease and the real efficacy of the surgical treatment.

Durability of bioprosthetic aortic valves in patients under the age of 60 years - rationale and design of the international INDURE registry

BACKGROUND

There is an ever-growing number of patients requiring aortic valve replacement (AVR). Limited data is available on the long-term outcomes and structural integrity of bioprosthetic valves in younger patients undergoing surgical AVR.

METHODS

The INSPIRIS RESILIA Durability Registry (INDURE) is a prospective, open-label, multicentre, international registry with a follow-up of 5 years to assess clinical outcomes of patients younger than 60 years who undergo surgical AVR using the INSPIRIS RESILIA aortic valve. INDURE will be conducted across 20-22 sites in Europe and Canada and intends to enrol minimum of 400 patients. Patients will be included if they are scheduled to undergo AVR with or without concomitant root replacement and/or coronary bypass surgery. The primary objectives are to 1) determine VARC-2 defined time-related valve safety at one-year (depicted as freedom from events) and 2) determine freedom from stage 3 structural valve degeneration (SVD) presenting as morphological abnormalities and severe haemodynamic valve degeneration at 5 years. Secondary objectives include the assessment of the haemodynamic performance of the valve, all stages of SVD, potential valve-in-valve procedures, clinical outcomes (in terms of New York Heart Association [NYHA] function class and freedom from valve-related rehospitalisation) and change in patient quality-of-life.

DISCUSSION

INDURE is a prospective, multicentre registry in Europe and Canada, which will provide much needed data on the long-term performance of bioprosthetic valves in general and the INSPIRIS RESILIA valve in particular. The data may help to gather a deeper understanding of the longevity of bioprosthetic valves and may expand the use of bioprosthetic valves in patients under the age of 60 years.

TRIAL REGISTRATION

ClinicalTrials.gov identifier: NCT03666741 (registration received September, 12th, 2018).

P5983Pre-operative physical performance as an independent predictor of in-hospital outcomes in older patients undergoing elective cardiac surgery

Introduction

Risk stratification of patients candidate to cardiac surgery is usually based on the Society of Thoracic Surgeons (STS) score or on the Euroscore II. However, these risk scores has limited predictive value in elderly patients.

Purpose

We conducted a study to determine whether the Short Physical Performance Battery (SPPB), a tool assessing physical performance, predicts hospital death and major morbidity, beyond STS risk score. The outcome was a composite end-point as defined by STS Major Morbidity or Operative Mortality (STS-MM) in STS Risk Model Outcomes: operative mortality, stroke, renal failure, prolonged mechanical ventilation, deep sternal wound infection, and reoperation.

Methods

In this prospective, single-center, cohort, hospital-based study, conducted at Careggi University Hospital, Florence, Italy, all patients aged 75+ years referred for an elective coronary aortic by-pass grafting, valvular surgery or combined cardiac surgery were evaluated pre-operatively. Assessment included SPPB, cognitive and functional status and evaluation of comorbidity. Patients receiving emergency/urgent cardiac surgery or a procedure not considered in the STS risk score calculator, who reported previous cardiac surgery or were clinically unstable were excluded. Participants were classified according to the STS-Predicted Risk Of Mortality (STS-PROM) as at low (<4%), intermediate (4 to 8%) or high risk (>8%).

Results

Out of 250 participants (females: 48.4%; mean age: 79.9 years), 148 (59.2%) were at low, 73 (29.2%) at intermediate and 29 (11.6%) at high risk, based on the STS-PROM. Mean±SEM SPPB score was 8.8±0.2, 7.1±0.4 and 6.0±0.7 in participants at low, intermediate, and high risk, respectively (p<0.001). The outcome occurred in 67 subjects (26.8%). SPPB score predicted the outcome in the entire study sample, controlling for STS-MM score, CKD, and anaemia (adjusted OR: 0.89, 95% CI 0.81–0.98 per each point increase; p 0.017). When analyses were repeated separately in participants with STS-PROM indicative of low (<4%) and in those at medium-high risk, the predictive value of SPPB was enhanced in the formers (adjusted OR 0.73, 95% CI 0.62–0.86 per each point increase; p<0.001- controlling for STS score), whereas was lost in the latter. An alternative model was subsequently tested, where STS score was not included and peripheral artery disease and creatinine (variables contributing to the STS score) were individually entered: SPPB was confirmed as a significant predictor also in this model, controlling for anaemia, peripheral artery disease, and creatinine. The corresponding AUC was 0.813 (Figure 1).

Figure 1

Conclusions

SPPB predicts mortality and major morbidity in older patients undergoing elective cardiac surgery, in particular in those classified as low-risk with the STS risk score. Use of SPPB should therefore be recommended to improve preoperative risk stratification of older patients.

Histopathological comparison of intramural coronary artery remodeling and myocardial fibrosis in obstructive versus end-stage hypertrophic cardiomyopathy

BACKGROUND

Although imaging techniques have demonstrated the existence of microvascular abnormalities in hypertrophic cardiomyopathy (HCM), a detailed histopathological assessment is lacking as well as a comparison between different phases of the disease. We aimed to compare microvasculopathy and myocardial fibrosis in hypertrophic obstructive cardiomyopathy (HOCM) versus end-stage (ES) HCM.

METHODS

27 myectomy specimens of HOCM patients and 30 ES-HCM explanted hearts were analyzed. Myocardial fibrosis was quantitatively determined with dedicated software and qualitatively classified as scar-like or interstitial. Intramural coronary arteries were evaluated separately according to lumen diameter: 100-500 μ versus <100 μ. Microvasculopathy assessment included the description of medial and intimal abnormalities and stenosis grading. The two subgroups were compared considering only the anterobasal septum of ES explanted hearts.

RESULTS

Median value of fibrosis in the anterobasal septum of explanted hearts was 34.6% as opposed to 10.3% of myectomy specimens (p < 0.001). Scar-like fibrosis was widely found in ES hearts while interstitial fibrosis was distinctive of HOCM (p < 0.001). All slides showed 100-500 μ microvasculopathy without any differences between subgroups in terms of lumen narrowing, extent of the disease and type of parietal involvement. Among ES hearts these lesions were associated with scar-like fibrosis (p = 0.034). <100-μ microvasculopathy was also frequent with no differences between subgroups.

CONCLUSIONS

Microvasculopathy is an intrinsic feature of HCM with similar characteristics across the natural phases of the disease. Conversely, myocardial fibrosis changes over time with ES hearts showing a three-fold greater amount, mainly scar-like. ES showed a closer association between microvasculopathy and replacement fibrosis.

Venous-arterial extracorporeal membrane oxygenation for refractory cardiac arrest: a clinical challenge

Guidelines stated that extracorporeal membrane oxygenation (ECMO) may improve outcomes after refractory cardiac arrest (CA) in cases of cardiogenic shock and witnessed arrest, where there is an underlying circulatory disease amenable to immediate corrective intervention. Due to the lack of randomized trials, available data are supported by small series and observational studies, being therefore characterized by heterogeneity and controversial results. In clinical practice, using ECMO involves quite a challenging medical decision in a setting where the patient is extremely vulnerable and completely dependent on the medical team's judgment. The present review focuses on examining existing evidence concerning inclusion and exclusion criteria, and outcomes (in-hospital and long-term mortality rates and neurological recovery) in studies performed in patients with refractory CA treated with ECMO. Discrepancies can be related to heterogeneity in study population, to differences in local health system organization in respect of the management of patients with CA, as well as to the fact that most investigations are retrospective. In the real world, patient selection occurs individually within each center based on their previous experience and expertise with a specific patient population and disease spectrum. Available evidence strongly suggests that in CA patients, ECMO is a highly costly intervention and optimal utilization requires a dedicated local health-care organization and expertise in the field (both for the technical implementation of the device and for the intensive care management of these patients). A careful selection of patients guarantees optimal utilization of resources and a better outcome.

Coronary embolism following valve surgery

A 55-year-old man experienced chest pain on the seventh day after valve surgery. Coronary angiography showed embolic occlusion of the left anterior descending coronary artery. The lesion was treated successfully with thrombectomy using the angiojet rheolytic thrombectomy system, resulting in rapid mechanical thrombolysis and removal via the effluent lumen of the catheter. Thrombolysis in Myocardial Infarction 3 flow was restored.

[Bivalirudin and cardiac surgery: two case reports]

Immune reactions to heparin and in particular heparin-induced thrombocytopenia are not rare and potentially fatal complications of heparin treatment. These conditions are frequently underdiagnosed in cardiac surgery. Moreover, few data are available in the literature about the use of alternative anticoagulants to heparin in this setting. We describe the successful use of bivalirudin in 2 patients with hypersensitivity to heparin who underwent cardiac surgery.

Acute traumatic rupture of the descending thoracic aorta: endovascular treatment

BACKGROUND

Acute traumatic rupture of the descending thoracic aorta is usually considered a surgical emergency; a conventional surgical approach carries high morbidity and mortality rates in the perioperative period. Endovascular surgery has recently been considered as providing a new therapeutic strategy for these patients. The aim of our study was to evaluate the feasibility along with early and midterm results of this procedure in our experience.

METHODS

Among 59 thoracic stent-graft procedures performed between May 2001 and May 2005 in our Department, 11 male patients (mean age 48+/-7.3 years) underwent endovascular repair for acute traumatic rupture of the descending thoracic aorta caused by motor vehicle accidents. The feasibility of endovascular repair and the size of the endograft were assessed on the basis of urgent spiral computed axial tomography. In all cases, the lesion was limited to the isthmus. Follow-up was performed at discharge, at 3, 6, and 12 months, and yearly thereafter by clinical examination, chest x-ray, and computed axial tomography scan.

RESULTS

Technical success was obtained in all patients, and no conversion to open repair was necessary. No intraoperative deaths or complications occurred, and no patient developed temporary or permanent neurologic deficits in the postoperative period. One patient died 22 days after the procedure from acute respiratory failure; cumulative 30-day mortality rate was 9.1%. The mean follow-up duration was 18.2+/-4.5 months. No death, endoleak, or reintervention occurred during follow-up.

COMMENTS

The treatment of acute traumatic rupture of the descending thoracic aorta with stent graft is a feasible and safe technique; it provides low morbidity and mortality rates in the early postoperative period, and midterm results are encouraging. However, long-term studies are worthwhile to evaluate the effectiveness and the durability of this procedure.

Novel drug development opportunity for relaxin in acute myocardial infarction: evidences from a swine model

The hormone relaxin has been shown to cause coronary vasodilation and to prevent ischemia/reperfusion-induced cardiac injury in rodents. This study provides evidence that relaxin, used as an adjunctive drug to coronary reperfusion, reduces the functional, biochemical, and histopathological signs of myocardial injury in an in vivo swine model of heart ischemia/reperfusion, currently used to test cardiotropic drugs for myocardial infarction. Human recombinant relaxin, given at reperfusion at doses of 1.25, 2.5, and 5 microg/kg b.wt. after a 30-min ischemia, caused a dose-related reduction of key markers of myocardial damage (serum myoglobin, CK-MB, troponin T) and cardiomyocyte apoptosis (caspase 3, TUNEL assay), as well as of cardiomyocyte contractile dysfunction (myofibril hypercontraction). Compared with the controls, relaxin also increased the uptake of the viability tracer 201Thallium and improved ventricular performance (cardiac index). Relaxin likely acts by reducing oxygen free radical-induced myocardial injury (malondialdehyde, tissue calcium overload) and inflammatory leukocyte recruitment (myeloperoxidase). The present findings show that human relaxin, given as a drug to counteract reperfusion-induced cardiac injury, affords a clear-cut protection to the heart of swine with induced myocardial infarction. The findings also provide background to future clinical trials with relaxin as adjunctive therapy to catheter-based coronary angioplasty in patients with acute myocardial infarction.