Mechanical and interventional support for heart failure with preserved ejection fraction: A review.

INTRODUCTION: Restrictive cardiomyopathy (RCM) and hypertrophic cardiomyopathy (HCM) are two disease processes that are known to progress to heart failure with preserved ejection fraction (HFpEF). Pharmacologic therapies for HFpEF have not improved patient outcomes or reduced mortality in this patient cohort; thus, there continues to be substantial interest in other treatment strategies, including surgical interventions and devices. In this article, we explore and report the current utility of percutaneous therapies and surgically implanted mechanical support in the treatment of patients with HFpEF. RESULTS: Treatment strategies include percutaneous interventions with interatrial shunts, left atrial assist devices (LAADs), and ventricular assist devices (VADs) in various configurations. Although VADs have been employed to treat patients with heart failure with reduced ejection fraction, their efficacy is limited in those with RCM and HCM. A left atrial-to-aortic VAD has been proposed to directly unload the left atrium, but data is limited. Alternatively, a LAAD could be placed in the mitral position and simultaneously unload the left atrium, while filling the left ventricle. CONCLUSION: A left atrial assist device in the mitral position is a promising solution to address the hemodynamic abnormalities in RCM and HCM; these pumps, however, are still under development.

Development of malignancies and their outcomes in patients supported on continuous-flow left ventricular assist devices-a systematic review.

BACKGROUND: With increased use of continuous-flow left ventricular assist devices (CF-LVAD), development of malignant tumors in this population is not uncommon. We sought to evaluate malignancies in CF-LVAD patients and evaluate the outcomes of treatment strategies. METHODS: Overall, 18 articles consisting of 28 patients were identified who developed malignancies after CF-LVAD placement. Patient-level data were extracted for systematic review. RESULTS: Median patient age was 60 years [59-67] and 85.7% (24/28) were male. CF-LVAD was placed as bridge-to-transplant (BTT) in 60.9% (14/23) of patients. The three most common malignancy types were GI in 35.7% (10/28) of patients, lung in 21.4% (6/28) and skin in 10.7% (3/28). Median time from CF-LVAD implant to malignancy diagnosis was 6.9 [2.5-12.8] months. Metastatic disease occurred in 17.9% (5/28) over a median time of 5.0 [1.0-82.0] months from the diagnosis. Surgical resection of the malignancy was performed in 57.1% (16/28) of patients. Our results showed that while there was a significantly higher probability of survival among patients who underwent surgery versus those who did not, when only stage I and II patients were included in the analysis, this difference was no longer statistically significant. Three patients were relisted for heart transplant after surgical treatment, and two received the transplant. CONCLUSIONS: Surgical management of malignancies in patients on CF-LVADs may improve survival and transplant eligibility status, therefore, a CF-LVAD should not always preclude surgical treatment.

Biomarkers of Cardiac Stress and Cytokine Release Syndrome in COVID-19: A Review.

PURPOSE OF REVIEW: The severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) resulted in the coronavirus 2019 (COVID-19) global pandemic. While primarily a respiratory virus, SARS-CoV-2 can cause myocardial injury. The pattern of injury, referred to as acute COVID-19 cardiovascular syndrome (ACovCS), is defined by cardiac troponin leak in the absence of obstructive coronary artery disease. Although the etiology of the injury is unknown, many speculate that a cytokine release syndrome (CRS) may be an important factor. We aim to review recent data concerning markers of cardiac injury in ACovCS and its relation to the CRS. RECENT FINDINGS: Cardiac injury was common in patients hospitalized for COVID-19, with both cardiac troponin and B-type natriuretic peptide (BNP) being elevated in this population. Biomarkers were correlated with illness severity and increased mortality. Cytokines such as IL-6 were more often elevated in patients with ACovCS. Myocarditis evident on cardiac MR following COVID-19 may be associated with cardiac troponin levels. The impact of dexamethasone and remdesivir, two therapies shown to have clinical benefit in COVID-19, on myocardial injury is unknown. Biomarkers of cardiac stress and injury in COVID-19 may be used to stratify risk in the future. Currently, there is no evidence that inhibition of cytokine release will reduce myocardial injury in patients with COVID-19.

Electromagnetic interference between implantable cardiac devices and continuous-flow left ventricular assist devices: a review.

Many patients with continuous-flow left ventricular assist devices (CF-LVAD) have other, co-existing implantable cardiac devices. While such devices often function appropriately, there is potential for electromagnetic interference (EMI). A literature review was performed to identify cases of EMI between CF-LVAD and other implanted cardiac devices to better understand their etiology, outcomes, and the strategies used to overcome such interference. The cases identified included interference between CF-LVAD and pacemakers, implantable cardioverter-defibrillators, and cardiac resynchronization therapy. The EMI reported in the current literature can be broken down into two general categories: interference leading to difficulty establishing telemetry and interference leading to impaired electrical signal sensing. Such interference led to inappropriate shock delivery in some cases. The type of interference, and thus treatments, differed and were device dependent. The strategies employed to reduce interference included metal shielding, physical manipulation to increase the distance between devices, and even exchange of the implanted device with another brand of the same class. To avoid such EMI in the future, physicians must be aware of the reported interference between certain devices, and manufacturers must work more closely to increase the compatibility of implanted cardiac devices.

Continuous-flow left ventricular assist device implantation in patients with preexisting mechanical mitral valves: a systematic review.

Introduction: A preexisting mechanical mitral valve (MMV) is thought to be a thrombogenic risk factor after continuous-flow left ventricular assist device (CF-LVAD) implantation. We sought to evaluate the management and outcomes of preexisting MMVs in patients following CF-LVAD implantation.Areas covered: An electronic search was performed to identify the presence of an MMV at the time of CF-LVAD implantation. Of the 1,168 studies identified, only five studies consisting of seven CF-LVAD patients met the inclusion criteria. Patient-level data were extracted and analyzed.Expert opinion: The median patient age was 54 (IQR: 42-61) years and 71.4% (5/7) were male. Non-ischemic cardiomyopathy was the predominant etiology (83.3%, 5/6) of heart failure, and bridge-to-transplant the predominant indication (85.7%, 6/7) for CF-LVAD. Aortic valve prosthesis was present in 42.9% (3/7) of patients. Median time from MMV to CF-LVAD placement was 6.0 years (IQR: 1.3-15.0). The median lower limit of the INR range was 2.8 (IQR: 2.1-3.0) and upper limit of the INR range was 3.5 (IQR: 3.1-3.5). During a median follow-up time of 120 (IQR: 70-201) days, there were no major GI bleeds or clinically significant thromboembolic complications. With adequate anticoagulation, preexisting MMVs in CF-LVAD patients did not result in clinically significant thromboembolic events.

Cardiac interventions in patients with achondroplasia: a systematic review.

Patients with achondroplasia and other causes of dwarfism suffer from increased rates of cardiovascular disease relative to the remainder of the population. Few studies have examined these patients when undergoing cardiac surgery or percutaneous intervention. This systematic review examines the literature to determine outcomes following cardiac intervention in this unique population. An electronic search was performed in the English literature to identify all reports of achondroplasia, dwarfism, and cardiac intervention. Of the 5,274 articles identified, 14 articles with 14 cases met inclusion criteria. Patient-level data was extracted and analyzed. Median patient age was 55.5 [interquartile ranges (IQR), 43.8, 59.8] years, median height 102.0 [98.8, 112.5] cm, median BMI 32.1 [27.0, 45.9], and 57.1% (8/14) were male. Of these 14 patients, nine had the following documented skeletal abnormalities: 66.7% (6/9) had scoliosis, 66.7% (6/9) had kyphosis, 11.1% (1/9) had lordosis, 11.1% (1/9) pectus carinatum and 11.1% (1/9) spinal stenosis. Coronary artery disease was present in 53.8% (7/13), and 30.8% (4/13) patients previously suffered a myocardial infarction. Of the eight patients who underwent cardiac surgery, 37.5% (3/8) underwent multivessel coronary artery bypass grafting, 37.5% (3/8) underwent aortic valve replacement, 25.0% (2/8) underwent type A aortic dissection repair, and the remaining 12.5% (1/8) underwent pulmonary thromboendarterectomy. Six patients underwent percutaneous intervention. Median cardiopulmonary bypass time was 136.5 [110.0, 178.8] minutes. Median arterial cannula size was 20.0 [20.0, 24.0] Fr. Bicaval cannulation was performed in all cases describing cannulation strategy (5/5). Median superior vena cava cannula size was 28.0 [28.0, 28.0] Fr, and inferior vena cava cannula size was 28.0 [28.0, 28.0] Fr. No mortality was reported with a median follow up time of 6.0 [6.0, 10.5] months. In conclusion, Common cardiac procedures can be performed with reasonable safety in this patient population. Operative adjustments may need to be made with respect to equipment to accommodate patient-specific needs.

Ventricular arrhythmias following continuous-flow left ventricular assist device implantation: A systematic review.

Ventricular arrhythmias (VA) are not uncommon after continuous-flow left ventricular assist device (CF-LVAD) implantation. In this systematic review, we sought to identify the patterns of VA that occurred following CF-LVAD implantation and evaluate their outcomes. An electronic search was performed to identify all articles reporting the development of VA following CF-LVAD implantation. VA was defined as any episode of ventricular fibrillation (VF) or sustained (>30 seconds) ventricular tachycardia (VT). Eleven studies were pooled for the analysis that included 393 CF-LVAD patients with VA. The mean patient age was 57 years [95%CI: 54; 61] and 82% [95%CI: 73; 88] were male. Overall, 37% [95%CI: 19; 60] of patients experienced a new onset VA after CF-LVAD implantation, while 60% [95%CI: 51; 69] of patients had a prior history of VA. Overall, 88% of patients [95%CI: 78; 94] were supported on HeartMate II CF-LVAD, 6% [95%CI: 3; 14] on HeartWare HVAD, and 6% [95%CI: 2; 13] on other CF-LVADs. VA was symptomatic in 47% [95%CI: 28; 68] of patients and in 50% [95%CI: 37; 52], early VA (<30 days from CF-LVAD) was observed. The 30-day mortality rate was 7% [95%CI: 5; 11]. Mean follow-up was 22.9 months [95%CI: 4.8; 40.8], during which 27% [95%CI: 17; 39] of patients underwent heart transplantation. In conclusion, approximately a third of patients had new VA following CF-LVAD placement. VA in CF-LVAD patients is often symptomatic, necessitates treatment, and carries a worse prognosis.

Clinical implications of LDH isoenzymes in hemolysis and continuous-flow left ventricular assist device-induced thrombosis.

Pump-induced thrombosis continues to be a major complication of continuous-flow left ventricular assist devices (CF-LVADs), which increases the risks of thromboembolic stroke, peripheral thromboembolism, reduced pump flow, pump failure, cardiogenic shock, and death. This is confounded by the fact that there is currently no direct measure for a proper diagnosis during pump support. Given the severity of this complication and its required treatment, the ability to accurately differentiate CF-LVAD pump thrombosis from other complications is vital. Hemolysis measured by elevated lactate dehydrogenase (LDH) enzyme levels, when there is clinical suspicion of pump-induced thrombosis, is currently accepted as an important metric used by clinicians for diagnosis; however, LDH is a relatively nonspecific finding. LDH exists as five isoenzymes in the body, each with a unique tissue distribution. CF-LVAD pump thrombosis has been associated with elevated serum LDH-1 and LDH-2, as well as decreased LDH-4 and LDH-5. Herein, we review the various isoenzymes of LDH and their utility in differentiating hemolysis seen in CF-LVAD pump thrombosis from other physiologic and pathologic conditions as reported in the literature.

Concomitant vs staged orthotopic liver transplant after cardiac surgical procedures.

BACKGROUND: In patients who require orthotopic liver transplant (OLT), cardiac surgery may be needed to optimize preoperative cardiac status for OLT. The aim of this systematic review was to evaluate patient characteristics and outcomes of those undergoing staged versus concomitant cardiac procedures with OLT. METHODS: An electronic search was performed to identify all case reports and series, from which patient-level data was extracted regarding cardiac procedures associated with OLT. After assessment for inclusion and exclusion criteria, 26 articles were pooled for systematic review. RESULTS: Overall, 49 patients were included in the analysis, of whom 12 (24%) underwent staged procedures and 37 (76%) underwent concomitant procedures. The median age was lower in the staged group [staged: 51 (IQR, 43.8-59.2) years vs. concomitant: 60 (IQR, 55.0-64.0) years, p = .02]. Other baseline characteristics were comparable between the two groups. For staged procedures, the median time between heart procedures and OLT was 2 (IQR, 1.0-3.5) months. The most commonly reported cardiac procedures were coronary artery bypass graft (CABG) [staged: 4/12 (33.3%) vs. concomitant: 21/37 (56.8%), p = .28], aortic valve replacement (AVR) [staged: 3/12 (25.0%) vs. concomitant: 19/37 (51.2%), p = .21], and transcatheter aortic valve replacement (TAVR) [staged: 4/12 (33.3%) vs. concomitant: 0/37 (0%), p = .002]. Regarding outcomes, there was a significantly shorter post-OLT hospital stay for those who had staged procedures versus those who had concomitant procedures [staged: 8 (IQR, 5-13) days vs. concomitant: 17 (IQR, 14-24) days, p = .007]. However, both groups had similar in-hospital mortality rates [staged: 1/12 (8.3%) vs. concomitant: 4/37 (10.8%), p = 1.0]. Overall survival stratified between the two groups was comparable. CONCLUSIONS: Patients who underwent the staged approach had a shorter post-transplant hospital stay, but comparable survival with respect to those who underwent concomitant cardiac procedures and OLT.