Systematic review of first-in-human and early phase clinical trials for surgically implantable biological mitral valve substitutes.

BACKGROUND: The aim of this review was the creation of uniform protocols to carry out and disclose First-In-Human and preliminary clinical trials of biological mitral valve replacement. The need for consistent methodology in these early trials was highlighted by the observation of significant variability in the methods and protocols used across different research. METHODS: An extensive search through six major databases was carried out to retrieve First-In-Human (FIH) clinical studies evaluating surgically implanted bio-prostheses in the mitral position. RESULTS: Following the PRISMA guideline, a systematic search identified 2082 published articles until March 2023. After removing duplicates (189), 1862 citations were screened, resulting in 22 eligible studies with 3332 patients for analysis. The mitral valve prostheses in these studies ranged from 21 to 37 mm, with the 29 mm size being most prevalent. Patient numbers varied, with the FIH subgroup including 31 patients and the older subgroup including 163 patients. Average study durations differed: the older subgroup lasted 4.57 years, the FIH subgroup 2.85 years, and the early phase studies spanned 8.05 years on average. CONCLUSION: FIH clinical report is essential to assess the significance of clinical data required for a "de novo" surgical implant. In addition, understanding the performance of the device, and recognizing the difficulties associated with the innovation constitute important lessons. These insights could be beneficial for the development of bioprosthetic heart valves and formulating a protocol for an FIH clinical trial.

Comparison of short-term outcomes between patients with extracranial carotid and/or intracranial atherosclerotic disease.

OBJECTIVE: To directly compare the 90-day outcomes of patients with symptomatic intracranial atherosclerotic disease (ICAD), extracranial carotid atherosclerotic disease (ECAD), and ICAD with concomitant ECAD. METHODS: From 2017-2021, patients who had (1) a transient ischemic attack or ischemic stroke within 30 days of admission as evaluated by a stroke neurologist and (2) ipsilateral ICAD and/or ECAD were prospectively enrolled. The cohort was divided into three groups: ICAD, ECAD, and ICAD with concomitant ECAD. The primary outcome assessed was 90-day ischemic stroke recurrence. Secondary outcomes included 90-day myocardial infarction (MI), all-cause mortality, and major adverse cardiovascular events (MACE, including cardiovascular death, nonfatal MI, and/or nonfatal ischemic stroke). RESULTS: Of 371 patients included in the analysis, 240 (64.7%) patients had ICAD only, 93 (25.0%) patients had ECAD only, and 38 (10.3%) patients had ICAD with concomitant ECAD. On multivariate time-to-event analysis adjusting for potential confounders and with ICAD as the reference comparator, the risk of 90-day clinical outcomes was highest among patients with ICAD and concomitant ECAD, with adjusted hazard ratios of 4.54 (95% CI=1.45, 14.2; p = 0.006), 9.32 (95% CI=1.58, 54.8; p = 0.014), and 8.52 (95% CI=3.54, 20.5; p < 0.001) for 90-day ischemic stroke, MI, and MACE, respectively. CONCLUSIONS: Patients with ICAD and concomitant ECAD have a poorer prognosis and are at significantly higher risk for 90-day ischemic stroke, MI, and MACE. Further research should focus on the evaluation of coronary atherosclerotic disease and more intensive medical therapy in this population.

Clinical efficacy and long-term immunogenicity of an early triple dose regimen of SARS-CoV-2 mRNA vaccination in cancer patients.

INTRODUCTION: Three doses of SARS-CoV-2 mRNA vaccines have been recommended for cancer patients to reduce the risk of severe disease. Anti-neoplastic treatment, such as chemotherapy, may affect long-term vaccine immunogenicity. METHOD: Patients with solid or haematological cancer were recruited from 2 hospitals between July 2021 and March 2022. Humoral response was evaluated using GenScript cPASS surrogate virus neutralisation assays. Clinical outcomes were obtained from medical records and national mandatory-reporting databases. RESULTS: A total of 273 patients were recruited, with 40 having haematological malignancies and the rest solid tumours. Among the participants, 204 (74.7%) were receiving active cancer therapy, including 98 (35.9%) undergoing systemic chemotherapy and the rest targeted therapy or immunotherapy. All patients were seronegative at baseline. Seroconversion rates after receiving 1, 2 and 3 doses of SARS-CoV-2 mRNA vaccination were 35.2%, 79.4% and 92.4%, respectively. After 3 doses, patients on active treatment for haematological malignancies had lower antibodies (57.3%±46.2) when compared to patients on immunotherapy (94.1%±9.56, P<0.05) and chemotherapy (92.8%±18.1, P<0.05). SARS-CoV-2 infection was reported in 77 (28.2%) patients, of which 18 were severe. No patient receiving a third dose within 90 days of the second dose experienced severe infection. CONCLUSION: This study demonstrates the benefit of early administration of the third dose among cancer patients.

Evaluating the relationship between right-to-left shunt and white matter hyperintensities in migraine patients: A systematic review and meta-analysis.

Introduction: White matter hyperintensities (WMHs) have been observed with greater frequency in patients with migraine and are thought to be associated with impaired cognition and function. The relationship between WMHs and right-to-left shunt (RLS) in migraine patients is unknown. We performed a systematic review to determine if there is an association between RLS and WMHs in patients with migraine. Methods: A systematic search of the literature was performed in PubMed and Embase using a suitable keyword search strategy from inception up to 16th June 2021. All studies that included patients with migraine and studied RLS and WMHs were included. Results: A total of 8 non-randomized observational studies comprising 1125 patients with migraine were included; 576 had an RLS, compared to 549 patients with no RLS. The mean age of the study populations ranged from 28.4 to 43 years, while the average duration from migraine diagnosis ranged from 5.1 to 19 years. The proportion of female to male patients was consistently higher in all studies (60.0-94.4%). Amongst migraine patients with RLS, 338 patients (58.7%) had WMHs. In contrast, 256 (46.6%) of migraine patients without RLS had WMHs. RLS was significantly associated with the presence of WMHs in migraine patients (OR: 1.56, 95% CI: 1.05-2.34, p = 0.03). Conclusion: In migraine patients, RLS was significantly associated with the presence of WMHs. Longitudinal studies are warranted to establish RLS as a risk factor for WMHs in patients with migraine, and to establish the significance of these changes.

The role of head-up cardiopulmonary resuscitation in sudden cardiac arrest: a systematic review and meta-analysis.

Background: Head-up cardiopulmonary resuscitation (HU-CPR) is an experimental treatment for sudden cardiac arrest (SCA), where cardiopulmonary resuscitation (CPR) is performed in a ramped position. We evaluated whether HU-CPR improved survival and surrogate outcomes as compared to standard CPR (S-CPR). Methods: Studies reporting on HU-CPR in SCA were searched for in PubMed, Embase and Cochrane Library from inception to May 1st 2021. Outcomes included neurologically-intact survival, 24-hour-survival, intracranial pressure (ICP), cerebral perfusion pressure (CerPP) and brain blood flow (BBF). Risk of bias was assessed using the GRADE assessment tool and Newcastle Ottawa Scale. Fixed- and random-effects models were used to estimate the pooled effects of HU-CPR at 30 degrees. Results: Thirteen articles met the criteria for inclusion (11 animal-only studies, one before-and-after human-only study, one study that utilized human- and animal-cadavers). Among animal studies, the most common implementation of HU-CPR was a 30-degree upward tilt of the head and thorax (n=7), while four studies investigated controlled sequential elevation (CSE). Two animal studies reported improved cerebral performance category (CPC) scores at 24-hour. The pooled effect on 24-hour survival was not statistically significant (P=0.37). The lone human study reported doubled return of spontaneous circulation (ROSC) (17.9% versus 34.2%, P<0.0001). The pooled effect on ROSC in three porcine studies was OR =3.63 (95% CI: 0.72-18.39). Pooled effects for surrogate physiological outcomes of intracranial cranial pressure (MD -14.08, 95% CI: -23.21 to -4.95, P=0.003), CerPP (MD 14.39, 95% CI: 3.07-25.72, P=0.01) and BBF (MD 0.14, 95% CI: 0.02-0.27, P=0.03), showed statistically significant benefit. Discussion: Overall, HU-CPR improved neurologically-intact survival at 24-hour, ROSC and physiological surrogate outcomes in animal models. Despite promising preclinical data, and one human observational study, clinical equipoise remains surrounding the role of HU-CPR in SCA, necessitating clarification with future randomized human trials.

The use of colchicine as an anti-inflammatory agent for stroke prevention in patients with coronary artery disease: a systematic review and meta-analysis.

OBJECTIVE: The primary objective is to evaluate the use of colchicine as an anti-inflammatory agent for stroke prevention in patients with coronary artery disease. BACKGROUND: There has been a rising number of randomized controlled trials conducted in patients with coronary artery disease on the use of colchicine in reducing cardiovascular complications. Recent publications suggest colchicine reduces the risk of stroke and other cardiovascular events. METHODS: We performed a systematic review of known trials in the current literature to characterize the clinical characteristics and outcomes of colchicine treatment in patients with coronary artery disease. A literature search was performed in PubMed, Embase and SCOPUS using a suitable keyword search strategy from inception to 4 June 2021. All studies evaluating cardiovascular outcomes of colchicine treatment in patients with coronary artery disease were included. RESULTS: The systemic review included 5 randomized controlled trials assessing a total of 11,790 patients. Majority of studies used a colchicine dosing regimen of 0.5 mg once daily, with the median follow-up duration ranging from 6 to 36 months. Meta-analytic estimates for stroke incidence highlighted a statistically significant benefit for patients that were administered colchicine compared to placebo (OR 0.47, 95% CI 0.27-0.81, p = 0.006), and a non-significant benefit for myocardial infarction. There was no significant association between colchicine treatment and the adverse effects of gastrointestinal symptoms and myopathy/myalgia. CONCLUSIONS: The use of colchicine reduces the risk of stroke in patients with a history of coronary artery disease, without a significant increase in gastrointestinal and myopathy/myalgia adverse effects.

N-Acetylcysteine's Renoprotective Effect in Cardiac Surgery: A Systematic Review and Meta-Analysis.

OBJECTIVE: To examine N-acetylcysteine's (NAC's) renoprotective effect in adult cardiac surgeryMethods: PubMed, Ovid Medline, and Embase were searched for randomized controlled trials published between January 1990 and May 2021 that investigated the effect of NAC in preventing acute kidney injury (AKI) in patients undergoing cardiac surgery. The inclusion criterion was studies that assessed the effect of NAC in comparison to placebo by measuring the incidence of AKI. RESULTS: Overall meta-analytic estimates of all 10 included trials showed that NAC did not have a significant effect (odds ratio [OR]: 0.84, 95% confidence interval [CI]: 0.64-1.10) on AKI. Further subgroup analysis did not show a significant benefit of NAC in preventing AKI. CONCLUSION: This meta-analysis suggests that NAC does not have a significant effect in reducing the incidence of AKI. However, there is notable heterogeneity among the included studies that could possibly account for the non-significant effect observed. It is worth noting that only one trial administered NAC high dosages perioperatively, and it is the only included trial to show a significant benefit in reducing the incidence of AKI (OR: 0.30, 95% CI: 0.11-0.81). Further studies on this dosage and duration of administration should be conducted to best elucidate the effect of administering NAC.

Centrifugal and Roller Pumps in Neonatal and Pediatric Extracorporeal Membrane Oxygenation: A Systematic Review and Meta-Analysis of Clinical Outcomes.

Extracorporeal membrane oxygenation (ECMO) is an invaluable means of supporting critically ill children with refractory respiratory or cardiac failure. Controversy remains; however, whether roller or centrifugal pumps are superior, particularly in infants. We performed a comprehensive search on PubMed, Embase, and Scopus for studies comparing the use of centrifugal and roller pumps in the pediatric and neonatal population from 1973 until March 1, 2020. All prospective and retrospective comparative studies were screened. Single-arm studies and those that included adult patients were excluded. The primary endpoint was survival to discharge. Secondary endpoints were complications (mechanical, cardiac, pulmonary, neurologic, renal, and hemolytic) and requirements for inotropic support. Random effects meta-analyses across all clinical endpoints were conducted. A total of four studies with 9111 patients were included. There was a statistically significant difference in in-hospital mortality, favoring the groups where roller pumps were used. Roller pumps were associated with fewer episodes of hemolysis, mechanical complications, cardiac complications, renal complications, and less inotropic support. ECMO with roller pumps may be associated with lower mortality in children. Roller pumps were associated with fewer complications, as well as reduced hemolysis and use of inotropes.

Partial Versus Complete Thymectomy in Non-Myasthenic Patients With Thymoma: A Systematic Review and Meta-Analysis of Clinical Outcomes.

OBJECTIVE: The optimal extent of surgical resection for non-myasthenic patients with thymoma is controversial. The objective of this meta-analysis was to compare complete to partial thymectomy in non-myasthenic patients for oncological and postoperative clinical outcomes. METHODS: We performed a PubMed and EMBASE search (from inception to January 2020) for English-language studies directly comparing partial thymectomy (thymomectomy) to complete thymectomy for thymoma resection. Clinical endpoints studied included overall and disease-free survival, Masaoka and World Health Organization staging, adjuvant therapy, postoperative complications, postoperative drainage, length of hospital stay, thymoma-related deaths, postresection development of myasthenia gravis, incomplete resection, and recurrence. Random effects meta-analyses across all clinical endpoints was done. RESULTS: There was no statistically significant difference between the two approaches with regard to recurrence (odds ratio [OR], 1.22; 95% confidence interval [CI], 0.78-1.92), completeness of resection (OR, 1.17; 95% CI, 0.66-2.10), adjuvant therapy (OR, 0.71; 95% CI, 0.40-1.26), or thymoma-related deaths (OR, 0.76; 95% CI, 0.12-4.66). There was a statistically significant decrease in postoperative complications (OR, 0.61; 95% CI, 0.39-0.97), drainage (mean difference [MD], -0.99; 95% CI, -1.98 to -0.01), and length of hospital length (MD, -1.88; 95% CI, -3.39 to -0.36) with partial thymectomy. CONCLUSIONS: The evidence appeared to suggest that partial thymectomy is oncologically equivalent to complete thymectomy for non-myasthenic patients with early-stage thymoma. There is an additional advantage of reduced postoperative complications and decreased length of hospital stay with partial thymectomy.

Intra-Arterial Adjunctive Medications for Acute Ischemic Stroke During Mechanical Thrombectomy: A Meta-Analysis.

BACKGROUND AND PURPOSE: In patients with acute ischemic stroke with large vessel occlusion, the role of intra-arterial adjunctive medications (IAMs), such as urokinase, tPA (tissue-type plasminogen activator), or glycoprotein IIb/IIIa inhibitors, during mechanical thrombectomy (MT) has not been clearly established. We aim to evaluate the efficacy and safety of concomitant or rescue IAM for acute ischemic stroke with large vessel occlusion patients undergoing MT. METHODS: We searched Medline, Embase, and Cochrane Stroke Group Trials Register databases from inception until March 13, 2020. We analyzed all studies with patients diagnosed with acute ischemic stroke with large vessel occlusion in the anterior or posterior circulation that provided data for the two treatment arms, (1) MT+IAM and (2) MT only, and also reported on at least one of the following efficacy outcomes, recanalization and 90-day modified Rankin Scale, or safety outcomes, symptomatic intracranial hemorrhage and 90-day mortality. Data were collated in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. RESULTS: Sixteen nonrandomized observational studies with a total of 4581 patients were analyzed. MT only was performed in 3233 (70.6%) patients, while 1348 (29.4%) patients were treated with both MT and IAM. As compared with patients treated with MT alone, patients treated with combination therapy (MT+IAM) had a higher likelihood of achieving good functional outcome (risk ratio, 1.13 [95% CI, 1.03-1.24]) and a lower risk of 90-day mortality (risk ratio, 0.82 [95% CI, 0.72-0.94]). There was no significant difference in successful recanalization (risk ratio, 1.02 [95% CI, 0.99-1.06]) and symptomatic intracranial hemorrhage between the two groups (risk ratio, 1.13 [95% CI, 0.87-1.46]). CONCLUSIONS: In acute ischemic stroke with large vessel occlusion, the use of IAM together with MT may achieve better functional outcomes and lower mortality rates. Randomized controlled trials are warranted to establish the safety and efficacy of IAM as adjunctive treatment to MT.

Anticoagulation After Isolated Mitral Valve Repair: A Systematic Review and Meta-Analysis of Clinical Outcomes.

Recommendations from international guidelines on optimal thromboprophylaxis after mitral repair are controversial and based on underpowered observational studies. This study aimed to evaluate the prophylactic use of warfarin after isolated mitral valve repair (MVr). A PubMed, EMBASE and Scopus search for studies in English on postoperative thromboprophylaxis for isolated MVr published to February 2020 was performed. The analysis excluded all studies with combined operations, mitral valve replacement and preoperative or postoperative atrial fibrillation. Clinical endpoints that were studied were thromboembolic events, bleeding complications and mortality. Random effects meta-analyses of the effect of postoperative warfarin use as compared with no warfarin use across all clinical endpoints was conducted. Warfarin use did not confer benefit in terms of thromboembolic prophylaxis after isolated MVr in patients without atrial fibrillation (OR, 0.97; 95% CI, 0.72-1.31). At the same time, it did not increase the risk of bleeding complications (OR, 1.10; 95% CI, 0.53-2.30) or affect overall survival during the follow-up period of the included studies (OR, 1.06; 95% CI, 0.28-4.05). To conclude, warfarin use is not necessary for patients after isolated MVr who remain in sinus rhythm. Recommendations from international guidelines may need to be revisited for this group of patients.

Cerebral Venous Thrombosis in Patients with COVID-19 Infection: a Case Series and Systematic Review.

BACKGROUND: There has been increasing reports associating the coronavirus disease 2019 (COVID-19) with thromboembolic phenomenon including ischemic strokes and venous thromboembolism. Cerebral venous thrombosis (CVT) is a rare neurovascular emergency that has been observed in some COVID-19 patients, yet much remains to be learnt of its underlying pathophysiology. OBJECTIVE: We present a case series of local patients with concomitant COVID-19 infection and CVT; and aim to perform a systematic review of known cases in the current literature. METHODS: We describe two patients with concomitant COVID-19 infection and CVT from a nationwide registry in Singapore. We then conducted a literature search in PubMed and Embase using a suitable keyword search strategy from 1st December 2019 to 11th June 2020. All studies reporting CVT in COVID-19 patients were included. RESULTS: Nine studies and 14 COVID-19 patients with CVT were studied. The median age was 43 years (IQR=36-58) and majority had no significant past medical conditions (60.0%). The time taken from onset of COVID-19 symptoms to CVT diagnosis was a median of 7 days (IQR=6-14). CVT was commonly seen in the transverse (75.0%) and sigmoid sinus (50.0%); 33.3% had involvement of the deep venous sinus system. A significant proportion of patients had raised D-dimer (75.0%) and CRP levels (50.0%). Two patients reported presence of antiphospholipid antibodies. Most patients received anticoagulation (91.7%) while overall mortality rate was 45.5%. CONCLUSIONS: The high mortality rate of CVT in COVID-19 infection warrants a high index of suspicion from physicians, and early treatment with anticoagulation should be initiated.

Left heart bypass versus circulatory arrest for open repair of thoracoabdominal aortic pathologies.

BACKGROUND: Most large-volume centres use left heart bypass (LHB) as their preferred organ protection strategy during repair of descending thoracic aortic (DTA) and thoracoabdominal aortic (TAA) pathologies. We investigate the use of hypothermic circulatory arrest (HCA) for similar pathologies and compare the outcomes of both. METHODS: A PubMed, Embase and Scopus search for studies in English on LHB versus HCA for repair of DTA and TAA pathologies published from inception till February 2020 was performed. Our analysis excluded studies without direct comparison of the two organ protection strategies. Clinical endpoints that were studied were 30-day mortality, post-operative stroke, spinal cord deficit, renal failure and respiratory failure. Random effects meta-analyses of the effect of the two strategies across all clinical endpoints were conducted. RESULTS: HCA is non-inferior to LHB across all clinical endpoints. In terms of 30-day mortality (odds ratio (OR) 1.19, 95% confidence interval (CI) 0.31-4.59, P = 0.14, I2 = 49%), stroke (OR 0.41, 95% CI 0.12-1.39, P = 0.97, I2 = 0%), spinal cord deficit (OR 0.56, 95% CI 0.22-1.45, P = 0.78, I2 = 0%), renal failure (OR 1.33, 95% CI 0.37-4.76, P = 0.98, I2 = 0%) and respiratory failure (OR 0.86, 95% CI 0.37-1.97, P = 0.16, I2 = 46%), there was no statistically significant difference between the two cohorts. CONCLUSION: Evidence is limited, but suggests that HCA alone provides adequate organ protection during repair of DTA and TAA pathologies, and has equivalent outcomes when compared to LHB.

COVID-19 and ischemic stroke: a systematic review and meta-summary of the literature.

Acute ischemic stroke (AIS) is a life-threatening complication of coronavirus disease 2019 (COVID-19) infection. Increasing reports suggest an association between COVID-19 and AIS, although the underlying mechanism remains uncertain. We performed a systematic review to characterize the clinical characteristics, neuroimaging findings, and outcomes of AIS in COVID-19 patients. A literature search was performed in PubMed and Embase using a suitable keyword search strategy from 1st December 2019 to 29th May 2020. All studies reporting AIS occurrence in COVID-19 patients were included. A total of 39 studies comprising 135 patients were studied. The pooled incidence of AIS in COVID-19 patients from observational studies was 1.2% (54/4466) with a mean age of 63.4 ± 13.1 years. The mean duration of AIS from COVID-19 symptoms onset was 10 ± 8 days, and the mean NIHSS score was 19 ± 8. Laboratory investigations revealed an elevated mean D-dimer (9.2 ± 14.8 mg/L) and fibrinogen (5.8 ± 2.0 g/L). Antiphospholipid antibodies were detected in a significant number of cases. The majority of AIS neuroimaging patterns observed was large vessel thrombosis, embolism or stenosis (62.1%, 64/103), followed by multiple vascular territory (26.2%, 27/103). A high mortality rate was reported (38.0%, 49/129). We report the pooled incidence of AIS in COVID-19 patients to be 1.2%, with a high mortality rate. Elevated D-dimer, fibrinogen and the presence of antiphospholipid antibodies appear to be prominent in COVID-19 patients with concomitant AIS, but further mechanistic studies are required to elucidate their role in pathogenesis.