[Perioperative stroke after aortic valve replacement for aortic stenosis - incidence, risk factors and short-term outcome]

INTRODUCTION

One of the most serious complications of surgical aortic valve replacement (SAVR) is stroke that can result in increased rates of complications, morbidity and mortality postoperatively. The aim of this study was to investigate incidence, risk factors and short-term outcome in a well defined cohort of SAVR-patients.

MATERIALS AND METHOD

A retrospective study on 740 consecutive aortic stenosis patients who underwent SAVR in Iceland 2002-2019. Patients with stroke were compared with non-stroke patients; including preoperative risk factors of cardiovascular disease, echocardiogram-results, rate of early postoperative complications other than stroke and 30 day mortality.

RESULTS

Mean age was 71 yrs (34% females) with 57% of the patients receiving stented bioprosthesis, 31% a stentless Freestyle®-valve and 12% a mechanical valve. Mean EuroSCORE-II was 3.6, with a maximum preop-gradient of 70 mmHg and an estimated valvular area of 0.73 cm2. Thirteen (1.8%) patients were diagnosed with stroke where hemiplegia (n=9), loss of consciousness (n=3) and/or aphasia (n=4) were the most common presenting symptoms. In 70% of cases the neurological symptoms resolved or disappeared in the first weeks and months after surgery. Only one patient out of 13 died within 30-days (7.7%). Stroke-patients had significantly lower BMI than non-stroke patients, but other risk factors of cardiovascular diseases, intraoperative factors or the rate of other severe postoperative complications than stroke were similar between groups. Total length of stay was 14 days vs. 10 days median, including 2 vs. 1 days in the ICU, in the stroke and non-stroke-groups, respectively.

CONCLUSIONS

The rate of stroke after SAVR was low (1.8%) and in line with other similar studies. Although a severe complication, most patients with perioperative stroke survived 30 days postoperatively and in majority of cases neurological symptoms recovered.

Postdischarge major bleeding, myocardial infarction, and mortality risk after coronary artery bypass grafting

OBJECTIVE

To investigate the incidence and mortality risk associated with postdischarge major bleeding after coronary artery bypass grafting (CABG), and relate this to the incidence of, and mortality risk from, postdischarge myocardial infarction.

METHODS

All patients undergoing first-time isolated CABG in Sweden in 2006-2017 and surviving 14 days after hospital discharge were included in a cohort study. Individual patient data from the SWEDEHEART Registry and five other mandatory nationwide registries were merged. Piecewise Cox proportional hazards models were used to investigate associations between major bleeding, defined as hospitalisation for bleeding, with subsequent mortality risk. Similar Cox proportional hazards models were used to investigate the association between postdischarge myocardial infarction and mortality risk.

RESULTS

Among 36 633 patients, 2429 (6.6%) had a major bleeding event and 2231 (6.1%) had a myocardial infarction. Median follow-up was 6.0 (range 0-11) years. Major bleeding was associated with higher mortality risk <30 days (adjusted HR (aHR)=20.2 (95% CI 17.3 to 23.5)), 30-365 days (aHR=3.8 (95% CI 3.4 to 4.3)) and >365 days (aHR=1.8 (95% CI 1.7 to 2.0)) after the event. Myocardial infarction was associated with higher mortality risk <30 days (aHR=20.0 (95% CI 16.7 to 23.8)), 30-365 days (aHR=4.1 (95% CI 3.6 to 4.8)) and >365 days (aHR=1.8 (95% CI 1.7 to 2.0)) after the event.

CONCLUSIONS

The increase in mortality risk associated with a postdischarge major bleeding after CABG is substantial and is similar to the mortality risk associated with a postdischarge myocardial infarction.

Recurrence of Atrial Fibrillation in Patients With New-Onset Postoperative Atrial Fibrillation After Coronary Artery Bypass Grafting

Importance

New-onset postoperative atrial fibrillation (POAF) occurs in approximately 30% of patients undergoing coronary artery bypass grafting (CABG). It is unknown whether early recurrence is associated with worse outcomes.

Objective

To test the hypothesis that early AF recurrence in patients with POAF after CABG is associated with worse outcomes.

Design, Setting, and Participants

This Swedish nationwide cohort study used prospectively collected data from the SWEDEHEART (Swedish Web System for Enhancement and Development of Evidence-Based Care in Heart Disease Evaluated According to Recommended Therapies) registry and 3 other mandatory national registries. The study included patients who underwent isolated first-time CABG between January 1, 2007, and December 31, 2020, and developed POAF. Data analysis was performed between March 6 and September 16, 2023.

Exposure

Early AF recurrence defined as an episode of AF leading to hospital care within 3 months after discharge.

Main Outcomes and Measures

The primary outcome was all-cause mortality. Secondary outcomes included ischemic stroke, any thromboembolism, heart failure hospitalization, and major bleeding within 2 years after discharge. The groups were compared with multivariable Cox regression models, with early AF recurrence as a time-dependent covariate. The hypothesis tested was formulated after data collection.

Results

Of the 35 329 patients identified, 10 609 (30.0%) developed POAF after CABG and were included in this study. Their median age was 71 (IQR, 66-76) years. The median follow-up was 7.1 (IQR, 2.9-9.0) years, and most patients (81.6%) were men. Early AF recurrence occurred in 6.7% of patients. Event rates (95% CIs) per 100 patient-years with vs without early AF recurrence were 2.21 (1.49-3.24) vs 2.03 (1.83-2.25) for all-cause mortality, 3.94 (2.92-5.28) vs 2.79 (2.56-3.05) for heart failure hospitalization, and 3.97 (2.95-5.30) vs 2.74 (2.51-2.99) for major bleeding. No association between early AF recurrence and all-cause mortality was observed (adjusted hazard ratio [AHR], 1.17 [95% CI, 0.80-1.74]; P = .41). In exploratory analyses, there was an association with heart failure hospitalization (AHR, 1.80 [95% CI, 1.32-2.45]; P = .001) and major bleeding (AHR, 1.92 [1.42-2.61]; P < .001).

Conclusions and Relevance

In this cohort study of early AF recurrence after POAF in patients who underwent CABG, no association was found between early AF recurrence and all-cause mortality. Exploratory analyses showed associations between AF recurrence and heart failure hospitalization, oral anticoagulation, and major bleeding.

Cardiopulmonary bypass management and acute kidney injury in cardiac surgery patients

BACKGROUND

Cardiopulmonary bypass (CPB) ensures tissue oxygenation during cardiac surgery. New technology allows continuous registration of CPB variables during the operation. The aim of the present investigation was to study the association between CPB management and the risk of postoperative acute kidney injury (AKI).

METHODS

This observational study based on prospectively registered data included 2661 coronary artery bypass grafting and/or valve patients operated during 2016-2020. Individual patient characteristics and postoperative outcomes collected from the SWEDEHEART registry were merged with CPB variables automatically registered every 20 s during CPB. Associations between CPB variables and AKI were analyzed with multivariable logistic regression models adjusted for patient characteristics.

RESULTS

In total, 387 patients (14.5%) developed postoperative AKI. After adjustments, longer time on CPB and aortic cross-clamp, periods of compromised blood flow during aortic cross-clamp time, and lower nadir hematocrit were associated with the risk of AKI, while mean blood flow, bladder temperature, central venous pressure, and mixed venous oxygen saturation were not. Patient characteristics independently associated with AKI were advanced age, higher body mass index, hypertension, diabetes mellitus, atrial fibrillation, lower left ventricular ejection fraction, estimated glomerular filtration rate <60 or >90 mL/min/m2 , and preoperative hemoglobin concentration below or above the normal sex-specific range.

CONCLUSIONS

To reduce the risk of AKI after cardiac surgery, aortic clamp time and CPB time should be kept short, and low hematocrit and periods of compromised blood flow during aortic cross-clamp time should be avoided if possible.

Statin treatment after surgical aortic valve replacement for aortic stenosis is associated with better long-term outcome

OBJECTIVES

The aim of this study was to evaluate the association between statin use after surgical aortic valve replacement for aortic stenosis and long-term risk for major adverse cardiovascular events (MACEs) in a large population-based, nationwide cohort.

METHODS

All patients who underwent isolated surgical aortic valve replacement due to aortic stenosis in Sweden 2006-2020 and survived 6 months after discharge were included. Individual patient data from 5 nationwide registries were merged. Primary outcome is MACE (defined as all-cause mortality, myocardial infarction or stroke). Multivariable Cox regression model adjusted for age, sex, comorbidities, valve type, operation year and secondary prevention medications is used to evaluate the association between time-updated dispense of statins and long-term outcome in the entire study population and in subgroups based on age, sex and comorbidities.

RESULTS

A total of 11 894 patients were included. Statins were dispensed to 49.8% (5918/11894) of patients at baseline, and 51.0% (874/1713) after 10 years. At baseline, 3.6% of patients were dispensed low dose, 69.4% medium dose and 27.0% high-dose statins. After adjustments, ongoing statin treatment was associated with a reduced risk for MACE [adjusted hazard ratio 0.77 (95% confidence interval 0.71-0.83). P < 0.001], mainly driven by a reduction in all-cause mortality [adjusted hazard ratio, 0.70 (0.64-0.76)], P < 0.001. The results were consistent in all subgroups.

CONCLUSIONS

The results suggest that statin therapy might be beneficial for patients undergoing surgical aortic valve replacement for aortic stenosis. Randomized controlled trials are warranted to establish causality between statin treatment and improved outcome.

[Incidence and outcomes of perioperative myocardial infarction associated with coronary artery bypass surgery]

INTRODUCTION

Perioperative myocardial infarction (PMI) after CABG can contribute to in-hospital morbidity and mortality, however, its clinical significance on long-term outcome, remains inadequately addressed. We studied both 30-day mortality and long-term effects of PMI in Icelandic CABG-patients.

MATERIALS AND METHODS

A retrospective nationwide-study on 1446 consecutive CABG-patients operated at Landspitali in Iceland 2002-2018 without evidence of preoperative myocardial infarction. PMI was defined as a tenfold elevetion in serum-CK-MB associated with new ECG changes or diagnostic imaging consistent with ischemia. Patients with PMI were compared to a reference group with uni- and multivariate analyses. Long-term and MACCE-free survival were estimated with the Kaplan-Meier method and logistic regression used to determine factors associated with PMI. The mean follow-up time was 8.3 years.

RESULTS

Out of 1446 patients 78 (5.4%) were diagnosed with PMI (range: 0-15.5%) with a significant annual decline in the incidence of PMI (12.7%, p<0.001). Over the same period preoperative aspirin use increased by 22.3% (p<0.018). PMI patients had a higher rate of short-term complications and a 11.5% 30-day mortality rate compared to 0.4% for non-PMI patients. PMI was found to be a predictor of 30-day mortality (OR 15.44, 95% CI: 6.89-34.67). PMI patients had worse 5-year MACCE-free survival (69.2% vs. 84.7, p=0,01), although overall survival was comparable between the groups.

CONCLUSIONS

Although PMI after CABG is associated with significantly higher rates of short-term complications and 30-day mortality, long-term survival was similar to the reference group. Therefore, the mortality risk attributable to PMI appears to diminish after the immediate postoperative period.

Renin-angiotensin system inhibition after surgical aortic valve replacement for aortic stenosis

OBJECTIVE

The optimal medical therapy after surgical aortic valve replacement (SAVR) for aortic stenosis remains unknown. Renin-angiotensin system (RAS) inhibitors could potentially improve cardiac remodelling and clinical outcomes after SAVR.

METHODS

All patients undergoing SAVR due to aortic stenosis in Sweden 2006-2020 and surviving 6 months after surgery were included. The primary outcome was major adverse cardiovascular events (MACEs; all-cause mortality, stroke or myocardial infarction). Secondary endpoints included the individual components of MACE and cardiovascular mortality. Time-updated adjusted Cox regression models were used to compare patients with and without RAS inhibitors. Subgroup analyses were performed, as well as a comparison between angiotensin-converting enzyme (ACE) inhibitors and angiotensin II receptor blockers (ARBs).

RESULTS

A total of 11 894 patients (mean age, 69.5 years, 40.4% women) were included. Median follow-up time was 5.4 (2.7-8.5) years. At baseline, 53.6% of patients were dispensed RAS inhibitors, this proportion remained stable during follow-up. RAS inhibition was associated with a lower risk of MACE (adjusted hazard ratio (aHR) 0.87 (95% CI 0.81 to 0.93), p<0.001), mainly driven by a lower risk of all-cause death (aHR 0.79 (0.73 to 0.86), p<0.001). The lower MACE risk was consistent in all subgroups except for those with mechanical prostheses (aHR 1.07 (0.84 to 1.37), p for interaction=0.040). Both treatment with ACE inhibitors (aHR 0.89 (95% CI 0.82 to 0.97)) and ARBs (0.87 (0.81 to 0.93)) were associated with lower risk of MACE.

CONCLUSION

The results of this study suggest that medical therapy with an RAS inhibitor after SAVR is associated with a 13% lower risk of MACE and a 21% lower risk of all-cause death.

[New-onset postoperative atrial fibrillation following coronary artery bypass grafting: Incidence, clinical course and short-term outcomes]

INTRODUCTION

The aims of this retrospective study were to investigate the incidence, clinical course and short term outcomes of new-onset postoperative atrial fibrillation (POAF) following coronary artery bypass surgery (CABG).

MATERIALS AND METHODS

A nation-wide study on 1622 patients who underwent CABG from 2006-2020 at Landspitali University Hospital. Clinical data were extracted from registries and 121 patients with pre-existing AF excluded, leaving 1501 patients for further analysis. Patient charts and postoperative ECGs were manually reviewed for determining details of POAF, which was defined as a postoperative episode of AF before discharge lasting at least 5 minutes. Patients with POAF (n=483) were compared to non-POAF patients (n=1018).

RESULTS

Altogether 483 (32.2%) patients developed POAF; the annual incidence decreasing over time (tau= -0,45, p=0.023). Most patients were diagnosed on the second day postoperatively (43.5%) and over 90% were diagnosed within 4 days. The median number of POAF episodes was 3 (IQR: 1-5), the first episode lasting 1-6 hours in half of the cases and the total POAF-duration being 12 hours median (IQR: 5-30). Over 94% of cases converted to sinus rythm before discharge, with 25 (5.3%) patients being discharged in AF. Most patients were treated with beta-blockers (98.8%), amiodarone (95%) and 14.9% with electric cardioversion. POAF-patients were older, had higher EuroSCORE II and a longer hospital stay, however, they had similar rates of early postoperative stroke and 30 day mortality.

CONCLUSION

The incidence of POAF remains high and was associated with prolonged hospital stay, but not significantly higher 30 day mortality or early postoperative stroke compared to patients in sinus rhythm. POAF-episodes were predominantly transient and almost 95% of patients were discharged in sinus rythm.

Socioeconomic factors and long-term mortality risk after surgical aortic valve replacement

Background

There is scarce knowledge about the association between socioeconomic status and mortality in patients undergoing surgical aortic valve replacement. This study explores the associations between income, education and marital status, and long-term mortality risk.

Methods

In this national registry-based observational cohort study we included all 14,537 patients aged >18 years who underwent isolated surgical aortic valve replacement for aortic stenosis in Sweden 1997-2020. Socioeconomic status and comorbidities were collected from three mandatory national registries. Cox regression models adjusted for patient characteristics and comorbidities were used to estimate the mortality risk.

Results

Mortality risk was higher for patients in the lowest versus the highest income quintile (adjusted hazard ratio [aHR] 1.36, 95 % confidence interval [CI]: 1.11-1.65), for patients with <10 years education versus >12 years (aHR 1.20, 95 % CI:1.08-1.33), and for patients who were not married/cohabiting versus those who were (aHR 1.24, 95 % CI:1.04-1.48). Patients with the most unfavorable socioeconomic status (lowest income, shortest education, never married/cohabiting) had an adjusted median survival of 2.9 years less than patients with the most favorable socioeconomic status (14.6 years, 95 % CI: 13.2-17.4 years vs. 11.7 years, 95 % CI: 9.8-14.4).

Conclusions

Low socioeconomic status in patients undergoing surgical aortic valve replacement is associated with shorter survival and an increased long-term adjusted mortality risk. These results emphasize the importance of identifying surgical aortic valve replacement patients with unfavorable socioeconomic situation and ensure sufficient post-discharge surveillance.

Regional transcriptomic profiling reveals immune system enrichment in nonfailing atria and all chambers of the failing human heart

The different chambers of the human heart demonstrate regional physiological traits and may be differentially affected during pathological remodeling, resulting in heart failure. Few previous studies, however, have characterized the different chambers at a transcriptomic level. We, therefore, conducted whole tissue RNA sequencing and gene set enrichment analysis of biopsies collected from the four chambers of adult failing (n = 8) and nonfailing (n = 11) human hearts. Atria and ventricles demonstrated distinct transcriptional patterns. When compared with nonfailing ventricles, the transcriptional pattern of nonfailing atria was enriched for many gene sets associated with cardiogenesis, the immune system and bone morphogenetic protein (BMP), transforming growth factor-β (TGF-β), MAPK/JNK, and Wnt signaling. Differences between failing and nonfailing hearts were also determined. The transcriptional pattern of failing atria was distinct compared with that of nonfailing atria and enriched for gene sets associated with the innate and adaptive immune system, TGF-β/SMAD signaling, and changes in endothelial, smooth muscle cell, and cardiomyocyte physiology. Failing ventricles were also enriched for gene sets associated with the immune system. Based on the transcriptomic patterns, upstream regulators associated with heart failure were identified. These included many immune response factors predicted to be similarly activated for all chambers of failing hearts. In summary, the heart chambers demonstrate distinct transcriptional patterns that differ between failing and nonfailing hearts. Immune system signaling may be a hallmark of all four heart chambers in failing hearts and could constitute a novel therapeutic target.NEW & NOTEWORTHY The transcriptomic patterns of the four heart chambers were characterized in failing and nonfailing human hearts. Both nonfailing atria had distinct transcriptomic patterns characterized by cardiogenesis, the immune system and BMP/TGF-β, MAPK/JNK, and Wnt signaling. Failing atria and ventricles were enriched for gene sets associated with the innate and adaptive immune system. Key upstream regulators associated with heart failure were identified, including activated immune response elements, which may constitute novel therapeutic targets.

Pacemaker implantation following tricuspid valve annuloplasty

Objective

Tricuspid annuloplasty is associated with increased risk of atrioventricular block and subsequent implantation of a permanent pacemaker. However, the exact incidence of permanent pacemaker, associated risk factors, and outcomes in this frame remain debated. The aim of the study was to report permanent pacemaker incidence, risk factors, and outcomes after tricuspid annuloplasty from nationwide databases.

Methods

By using data from multiple Swedish mandatory national registries, all patients (n = 1502) who underwent tricuspid annuloplasty in Sweden from 2006 to 2020 were identified. Patients who needed permanent pacemaker within 30 days from surgery were compared with those who did not. The cumulative incidence of permanent pacemaker implantation was estimated. A multivariable logistic regression model was fit to identify risk factors of 30-day permanent pacemaker implantation. The association between permanent pacemaker implantation and long-term survival was evaluated with multivariable Cox regression.

Results

The 30-day permanent pacemaker rate was 14.2% (214/1502). Patients with permanent pacemakers were older (69.8 ± 10.3 years vs 67.5 ± 12.4 years, P = .012). Independent risk factors of permanent pacemaker implantation were concomitant mitral valve surgery (odds ratio, 2.07; 95% CI, 1.34-3.27), ablation surgery (odds ratio, 1.59; 95% CI, 1.12-2.23), and surgery performed in a low-volume center (odds ratio, 1.85; 95% CI, 1.17-2.83). Permanent pacemaker implantation was not associated with increased long-term mortality risk (adjusted hazard ratio, 0.74; 95% CI, 0.53-1.03).

Conclusions

This nationwide study demonstrated a high risk of permanent pacemaker implantation within 30 days of tricuspid annuloplasty. However, patients who needed a permanent pacemaker did not have worse long-term survival, and the cumulative incidence of heart failure and major adverse cardiovascular events was similar to patients who did not receive a permanent pacemaker.

The left atrial appendage closure by surgery-2 (LAACS-2) trial protocol rationale and design of a randomized multicenter trial investigating if left atrial appendage closure prevents stroke in patients undergoing open-heart surgery irrespective of preoperative atrial fibrillation status and stroke risk

BACKGROUND

Current recommendations regarding the use of surgical left atrial appendage (LAA) closure to prevent thromboembolisms lack high-level evidence. Patients undergoing open-heart surgery often have several cardiovascular risk factors and a high occurrence of postoperative atrial fibrillation (AF)-with a high recurrence rate-and are thus at a high risk of stroke. Therefore, we hypothesized that concomitant LAA closure during open-heart surgery will reduce mid-term risk of stroke independently of preoperative AF status and CHA2DS2-VASc score.

METHODS

This protocol describes a randomized multicenter trial. Consecutive participants ≥18 years scheduled for first-time planned open-heart surgery from cardiac surgery centers in Denmark, Spain, and Sweden are included. Both patients with a previous diagnosis of paroxysmal or chronic AF, as well as those without AF, are eligible to participate, irrespective of their CHA2DS2-VASc score. Patients already planned for ablation or LAA closure during surgery, with current endocarditis, or where follow-up is not possible are considered noneligible. Patients are stratified by site, surgery type, and preoperative or planned oral anticoagulation treatment. Subsequently, patients are randomized 1:1 to either concomitant LAA closure or standard care (ie, open LAA). The primary outcome is stroke, including transient ischemic attack, as assigned by 2 independent neurologists blinded to the treatment allocation. To recognize a 60% relative risk reduction of the primary outcome with LAA closure, 1,500 patients are randomized and followed for 2 years (significance level of 0.05 and power of 90%).

CONCLUSIONS

The LAACS-2 trial is likely to impact the LAA closure approach in most patients undergoing open-heart surgery.

TRIAL REGISTRATION

NCT03724318.

A latent cardiomyocyte regeneration potential in human heart disease

Cardiomyocytes in the adult human heart show a regenerative capacity, with an annual renewal rate around 0.5%. Whether this regenerative capacity of human cardiomyocytes is employed in heart failure has been controversial. Using retrospective 14C birth dating we analyzed cardiomyocyte renewal in patients with end-stage heart failure. We show that cardiomyocyte generation is minimal in end-stage heart failure patients at rates 18-50 times lower compared to the healthy heart. However, patients receiving left ventricle support device therapy, who showed significant functional and structural cardiac improvement, had a >6-fold increase in cardiomyocyte renewal relative to the healthy heart. Our findings reveal a substantial cardiomyocyte regeneration potential in human heart disease, which could be exploited therapeutically.

Cardiopulmonary bypass management and risk of new-onset atrial fibrillation after cardiac surgery

OBJECTIVES

Cardiopulmonary bypass (CPB) management may potentially play a role in the development of new-onset atrial fibrillation (AF) after cardiac surgery. The aim of this study was to explore this potential association.

METHODS

Patients who underwent coronary artery bypass grafting and/or valvular surgery during 2016-2020 were included in an observational single-centre study. Data collected from the Swedish Web System for Enhancement and Development of Evidence-Based Care in Heart Disease Evaluated According to Recommended Therapies registry and a local CPB database were merged. Associations between individual CPB variables (CPB and aortic clamp times, arterial and central venous pressure, mixed venous oxygen saturation, blood flow index, bladder temperature and haematocrit) and new-onset AF were analysed using multivariable logistic regression models adjusted for patient characteristics, comorbidities and surgical procedure.

RESULTS

Out of 1999 patients, 758 (37.9%) developed new-onset AF. Patients with new-onset postoperative AF were older, had a higher incidence of previous stroke, worse renal function and higher EuroSCORE II and CHA2DS2-VASc scores and more often underwent valve surgery. Longer CPB time [adjusted odds ratio 1.05 per 10 min (95% confidence interval 1.01-1.08); P = 0.008] and higher flow index [adjusted odds ratio 1.21 per 0.2 l/m2 (95% confidence interval 1.02-1.42); P = 0.026] were associated with an increased risk for new-onset AF, while the other variables were not. A sensitivity analysis only including patients with isolated coronary artery bypass grafting supported the primary analyses.

CONCLUSIONS

CPB management following current guideline recommendations appears to have minor or no influence on the risk of developing new-onset AF after cardiac surgery.

PCI or CABG for left main coronary artery disease: the SWEDEHEART registry

AIMS

An observational nationwide all-comers prospective register study to analyse outcomes after coronary artery bypass grafting (CABG) or percutaneous coronary intervention (PCI) in unprotected left main coronary artery (LMCA) disease.

METHODS AND RESULTS

All patients undergoing coronary angiography in Sweden are registered in the Swedish Web-system for Enhancement and Development of Evidence-based care in Heart disease Evaluated According to Recommended Therapies registry. Between 01/01/2005 and 12/31/2015, 11 137 patients with LMCA disease underwent CABG (n = 9364) or PCI (n = 1773). Patients with previous CABG, ST-elevation myocardial infarction (MI) or cardiac shock were excluded. Death, MI, stroke, and new revascularization during follow-up until 12/31/2015 were identified using national registries. Cox regression with inverse probability weighting (IPW) and an instrumental variable (IV), administrative region, were used. Patients undergoing PCI were older, had higher prevalence of comorbidity but lower prevalence of three-vessel disease. PCI patients had higher mortality than CABG patients after adjustments for known cofounders with IPW analysis (hazard ratio [HR] 2.0 [95% confidence interval (CI) 1.5-2.7]) and known/unknown confounders with IV analysis (HR 1.5 [95% CI 1.1-2.0]). PCI was associated with higher incidence of major adverse cardiovascular and cerebrovascular events (MACCE; death, MI, stroke, or new revascularization) than CABG, with IV analysis (HR 2.8 [95% CI 1.8-4.5]). There was a quantitative interaction for diabetic status regarding mortality (P = 0.014) translating into 3.6 years (95% CI 3.3-4.0) longer median survival time favouring CABG in patients with diabetes.

CONCLUSION

In this non-randomized study, CABG in patients with LMCA disease was associated with lower mortality and fewer MACCE compared to PCI after multivariable adjustment for known and unknown confounders.

Plasma and cerebrospinal fluid concentrations of neurofilament light protein correlate in patients with idiopathic normal pressure hydrocephalus

BACKGROUND

Neurofilament light chain protein (NFL), a marker of neuronal axonal degeneration, is increased in cerebrospinal fluid (CSF) of patients with idiopathic normal pressure hydrocephalus (iNPH). Assays for analysis of NFL in plasma are now widely available but plasma NFL has not been reported in iNPH patients. Our aim was to examine plasma NFL in iNPH patients and to evaluate the correlation between plasma and CSF levels, and whether NFL levels are associated with clinical symptoms and outcome after shunt surgery.

METHODS

Fifty iNPH patients with median age 73 who had their symptoms assessed with the iNPH scale and plasma and CSF NFL sampled pre- and median 9 months post-operatively. CSF plasma was compared with 50 healthy controls (HC) matched for age and gender. Concentrations of NFL were determined in plasma using an in-house Simoa method and in CSF using a commercially available ELISA method.

RESULTS

Plasma NFL was elevated in patients with iNPH compared to HC (iNPH: 45 (30-64) pg/mL; HC: 33 (26-50) (median; Q1-Q3), p = 0.029). Plasma and CSF NFL concentrations correlated in iNPH patients both pre- and postoperatively (r = 0.67 and 0.72, p < 0.001). We found only weak correlations between plasma or CSF NFL and clinical symptoms and no associations with outcome. A postoperative NFL increase was seen in CSF but not in plasma.

CONCLUSIONS

Plasma NFL is increased in iNPH patients and concentrations correlate with CSF NFL implying that plasma NFL can be used to assess evidence of axonal degeneration in iNPH. This finding opens a window for plasma samples to be used in future studies of other biomarkers in iNPH. NFL is probably not a very useful marker of symptomatology or for prediction of outcome in iNPH.

Metagenomic sequencing of human cardiac tissue reveals Microbial RNA which correlates with Toll-like receptor-associated inflammation in patients with heart disease

Cardiovascular disease (CVD) is strongly associated with chronic low-grade inflammation, involving activated Toll-like receptors and their downstream cellular machinery. Moreover, CVD and other related inflammatory conditions are associated with infiltration of bacteria and viruses originating from distant body sites. Thus, in this study we aimed to map the presence of microbes in the myocardium of patients with heart disease that we previously found to display upregulated Toll-like receptor signaling. We performed metagenomics analysis of atrial cardiac tissue from patients undergoing coronary artery bypass grafting (CABG) or aortic valve replacement (AVR) and compared with atrial cardiac tissue from organ donors. A total of 119 species of bacteria and seven species of virus were detected in the cardiac tissue. RNA expression of five bacterial species were increased in the patient group of which L. kefiranofaciens correlated positively with cardiac Toll-like receptor-associated inflammation. Interaction network analysis revealed four main gene set clusters involving cell growth and proliferation, Notch signaling, G protein signaling and cell communication in association with L. kefiranofaciens RNA expression. Taken together, intracardial expression of L. kefiranofaciens RNA correlates with pro-inflammatory markers in the diseased cardiac atrium and may have an effect on specific signaling processes important for cell growth, proliferation and cell communication.

Dual or single antiplatelet therapy after coronary surgery for acute coronary syndrome (TACSI trial): Rationale and design of an investigator-initiated, prospective, multinational, registry-based randomized clinical trial

The TACSI trial (ClinicalTrials.gov Identifier: NCT03560310) tests the hypothesis that 1-year treatment with dual antiplatelet therapy with acetylsalicylic acid (ASA) and ticagrelor is superior to only ASA after isolated coronary artery bypass grafting (CABG) in patients with acute coronary syndrome. The TACSI trial is an investigator-initiated pragmatic, prospective, multinational, multicenter, open-label, registry-based randomized trial with 1:1 randomization to dual antiplatelet therapy with ASA and ticagrelor or ASA only, in patients undergoing first isolated CABG, with a planned enrollment of 2200 patients at Nordic cardiac surgery centers. The primary efficacy end point is a composite of time to all-cause death, myocardial infarction, stroke, or new coronary revascularization within 12 months after randomization. The primary safety end point is time to hospitalization due to major bleeding. Secondary efficacy end points include time to the individual components of the primary end point, cardiovascular death, and rehospitalization due to cardiovascular causes. High-quality health care registries are used to assess primary and secondary end points. The patients will be followed for 10 years. The TACSI trial will give important information useful for guiding the antiplatelet strategy in acute coronary syndrome patients treated with CABG.

[Analysis with viscoelastic hemostatic assays - a guide]

Viscoelastic hemostasis analyses (VHA) are a complement in the evaluation of hemostasis in patients with major bleeding. The analysis measures viscoelastic changes in whole blood and the results give an overview of several components of hemostasis. VHA can be used to optimize fibrinogen levels, platelet and plasma substitution. The main clinical evidence supporting this strategy is in trauma, obstetric bleeding, heart and liver surgery, where algorithms based on VHA results facilitate individualized therapy. VHA measurement is of limited value to exclude treatment with anticoagulants and platelet inhibitors. Quality control aspects are also more cumbersome since whole blood with limited sustainability is used. Newer, more automated versions of the instruments have increased the reproducibility. The main advantage of VHA is the fast turn-around time and their role in guiding treatment in an emergency situation with bleeding.

Associations between new-onset postoperative atrial fibrillation and long-term outcome in patients undergoing surgical aortic valve replacement

OBJECTIVES

Data on prognostic implications of new-onset postoperative atrial fibrillation (POAF) after surgical aortic valve replacement (SAVR) is limited. We sought to explore associations between POAF, early-initiated oral anticoagulation (OAC), and long-term outcome after SAVR and combined SAVR+CABG.

METHODS

This is a retrospective, population-based study including all isolated SAVR (n = 7038) and combined SAVR and CABG patients (n = 3854) without a history of preoperative atrial fibrillation in Sweden 2007-2017. Individual patient data was merged from four nationwide registries. Inverse Probability of Treatment Weighting (IPTW) adjusted Cox regression models were employed separately in SAVR and SAVR+CABG patients. Median follow-up time was 4.7 years (range 0-10 years).

RESULTS

POAF occurred in 44.5% and 50.7% of SAVR and SAVR+CABG patients, respectively. In SAVR patients, POAF was associated with increased long-term risk of death [adjusted hazard ratio (aHR) 1.21 (95% confidence interval 1.06-1.37)], ischaemic stroke [aHR 1.32 (1.08-1.59)], any thromboembolism, heart failure hospitalization, and recurrent atrial fibrillation. In SAVR+CABG, POAF was associated with death [aHR 1.31 (1.14-1.51)], recurrent atrial fibrillation, and heart failure, but not with ischaemic stroke [aHR 1.04 (0.84-1.29)] or thromboembolism. OAC was dispensed within 30 days after discharge to 67.0% and 65.9% respectively of SAVR and SAVR+CABG patients with POAF. Early initiated OAC was not associated with reduced risk of death, ischaemic stroke or thromboembolism in any group of patients.

CONCLUSIONS

POAF after SAVR is associated with an increased risk of long-term mortality and morbidity. Further studies are warranted to clarify the role of OAC in SAVR patients with POAF.

Expression of Stem Cell Niche-Related Biomarkers at the Base of the Human Tricuspid Valve

Stem cell niches have been thoroughly investigated in tissue with high regenerative capacity but not in tissues where cell turnover is slow, such as the human heart. The left AtrioVentricular junction (AVj), the base of the mitral valve, has previously been proposed as a niche region for cardiac progenitors in the adult human heart. In the present study, we explore the right side of the human heart, the base of the tricuspid valve, to investigate the potential of this region as a progenitor niche. Paired biopsies from explanted human hearts were collected from multi-organ donors (N = 12). The lateral side of the AVj, right atria (RA), and right ventricle (RV) were compared for the expression of stem cell niche-related biomarkers using RNA sequencing. Gene expression data indicated upregulation of genes related to embryonic development and extracellular matrix (ECM) composition in the proposed niche region, that is, the AVj. In addition, immunohistochemistry showed high expression of the fetal cardiac markers MDR1, SSEA4, and WT1 within the same region. Nuclear expression of HIF1α was detected suggesting hypoxia. Rare cells were found with the co-staining of the proliferation marker PCNA and Ki67 with cardiomyocyte nuclei marker PCM1 and cardiac Troponin T (cTnT), indicating proliferation of small cardiomyocytes. WT1+/cTnT+ and SSEA4+/cTnT+ cells were also found, suggesting cardiomyocyte-specific progenitors. The expression of the stem cell markers gradually decreased with distance from the tricuspid valve. No expression of these markers was observed in the RV tissue. In summary, the base of the tricuspid valve is an ECM-rich region containing cells with expression of several stem cell niche-associated markers. Co-expression of stem cell markers with cTnT indicates cardiomyocyte-specific progenitors. We previously reported similar data from the base of the mitral valve and thus propose that human adult cardiomyocyte progenitors reside around both atrioventricular valves.

Type A Aortic Dissection Repair in Patients With Prior Cardiac Surgery

BACKGROUND

Emergency surgery for acute type A aortic dissection in patients with previous cardiac surgery is controversial. This study aimed to evaluate the association between previous cardiac surgery and outcomes after surgery for acute type A aortic dissection, to appreciate whether emergency surgery can be offered with acceptable risks.

METHODS

All patients operated on for acute type A aortic dissection between 2005 and 2014 from the Nordic Consortium for Acute Type A Aortic Dissection database were eligible. Patients with previous cardiac surgery were compared with patients without previous cardiac surgery. Univariable and multivariable statistical analyses were performed to identify predictors of 30-day mortality and early major adverse events (a secondary composite endpoint comprising 30-day mortality, perioperative stroke, postoperative cardiac arrest, or de novo dialysis).

RESULTS

In all, 1159 patients were included, 40 (3.5%) with previous cardiac surgery. Patients with previous cardiac surgery had higher 30-day mortality (30% vs 17.8%, P = .049), worse medium-term survival (51.7% vs 71.2% at 5 years, log rank P = .020), and higher unadjusted prevalence of major adverse events (52.5% vs 35.7%, P = .030). In multivariable analysis, previous cardiac surgery was not associated with 30-day mortality (odds ratio 0.78; 95% CI, 0.30-2.07; P = .624) or major adverse events (odds ratio 1.07; 95% CI, 0.45-2.55, P = .879).

CONCLUSIONS

Major adverse events after surgery for acute type A aortic dissection were more frequent in patients with previous cardiac surgery. Previous cardiac surgery itself was not an independent predictor for adverse events, although the small sample size precludes definite conclusions. Previous cardiac surgery should not deter from emergency surgery.

Hemostatic effects of a dextran-based priming solution for cardiopulmonary bypass: A secondary analysis of a randomized clinical trial

INTRODUCTION

Intravascular fluids administered to patients may influence hemostasis. In patients undergoing cardiac surgery with cardiopulmonary bypass, the heart-lung machine is primed with 1300 ml of fluid. We assessed postoperative coagulation and platelet function in patients randomized to two different priming solutions, one colloid-based (dextran 40) and one crystalloid-based.

MATERIALS AND METHODS

Eighty-four elective cardiac surgery patients were randomized to either a dextran-based prime or Ringer's acetate with added mannitol. Blood samples were collected before, and 2 and 24 h after cardiopulmonary bypass. Coagulation was assessed by standard coagulation tests and rotational thromboelastometry. Platelet function was assessed with impedance aggregometry. Bleeding volumes and transfusion requirements were recorded.

RESULTS

Comparing the groups 2 h after bypass, the dextran group showed lower hemoglobin concentration, hematocrit, platelet count, and fibrinogen concentration, and higher INR and aPTT, as well as longer clot formation time (+41 ± 21 % vs. +8 ± 18 %, p < 0.001) and a larger reduction in fibrinogen-dependent clot strength (-37 ± 12 % vs. -7 ± 20 %, p < 0.001). Adenosine diphosphate-dependent platelet activation was reduced in the dextran group but not in the crystalloid group 2 h after bypass (-14 ± 29 % vs. -1 ± 41 %, p = 0.041). No significant between-group differences in hemostatic variables remained after 24 h, and no significant differences in perioperative bleeding volumes, re-explorations for bleeding, or transfusion rates were observed.

CONCLUSIONS

Compared to a crystalloid solution, a dextran-based prime had measurable negative impact on hemostatic variables but no detectable increase in bleeding volume or transfusion requirements in cardiac surgery patients.

Direct intramyocardial injection of VEGF mRNA in patients undergoing coronary artery bypass grafting

Vascular endothelial growth factor A (VEGF-A) has therapeutic cardiovascular effects, but delivery challenges have impeded clinical development. We report the first clinical study of naked mRNA encoding VEGF-A (AZD8601) injected into the human heart. EPICCURE (ClinicalTrials.gov: NCT03370887) was a randomized, double-blind study of AZD8601 in patients with left ventricular ejection fraction (LVEF) 30%-50% who were undergoing elective coronary artery bypass surgery. Thirty epicardial injections of AZD8601 (total 3 mg) or placebo in citrate-buffered saline were targeted to ischemic but viable myocardial regions mapped using quantitative [15O]-water positron emission tomography. Seven patients received AZD8601 and four received placebo and were followed for 6 months. There were no deaths or treatment-related serious adverse events and no AZD8601-associated infections, immune reactions, or arrhythmias. Exploratory outcomes indicated potential improvement in LVEF, Kansas City Cardiomyopathy Questionnaire scores, and N-terminal pro-B-type natriuretic peptide levels, but the study is limited in size, and significant efficacy conclusions are not possible from the dataset. Naked mRNA without lipid encapsulation may provide a safe delivery platform for introducing genetic material to cardiac muscle, but further studies are needed to confirm efficacy and safety in a larger patient pool.

Long-term antithrombotic therapy after coronary artery bypass grafting in patients with preoperative atrial fibrillation. A nationwide observational study from the SWEDEHEART registry

AIMS

To provide data guiding long-term antithrombotic therapy after coronary artery by-pass grafting (CABG) in patients with preoperative atrial fibrillation (AF).

METHODS AND RESULTS

From the SWEDEHEART registry, we included all patients, between January 2006 and September 2016, with preoperative AF and CHA₂DS₂-VASC score ≥2, undergoing CABG. Based on dispensed prescriptions 12 to 18 months after CABG, patients were divided in 3 groups: use of platelet inhibitors (PI) only, oral anticoagulant (OAC) only or a combination of OAC + PI. Outcomes were: Major adverse cardiac and cerebrovascular events (MACCE, [all-cause death, myocardial infarction, or stroke]), net adverse clinical events (NACE, [MACCE or bleeding]) and the individual components of NACE. Inverse probability of treatment weighting was used to adjust for the non-randomized study design. Among 2,564 patients, 1,040 (41%) were treated with PI alone, 1,064 (41%) with OAC alone, and 460 (18%) with PI + OAC. Treatment with PI alone was associated with higher risk for MACCE (adjusted HR 1.43, 95% CI 1.09-1.88), driven by higher risk for stroke and MI, compared with OAC alone. Treatment with PI + OAC, was associated with higher risk for NACE (adjusted HR 1.40, 95% CI 1.06-1.85), driven by higher risk for bleeds, compared with OAC alone.

CONCLUSION

In this real-world observational study, a high proportion of patients with AF, undergoing CABG, did not receive a long-term OAC therapy. Treatment with OAC alone was associated with a net clinical benefit, compared with PI alone or PI + OAC.

Medical therapy after surgical aortic valve replacement for aortic regurgitation

OBJECTIVE

Current clinical guidelines have no specific recommendations regarding medical therapy after surgical aortic valve replacement in patients with aortic regurgitation. We studied the association between medical therapy with RAS inhibitors, statins and beta-blockers, and long-term major adverse cardiovascular events.

METHODS

All patients undergoing valve replacement due to aortic regurgitation between 2006-2017 in Sweden and alive six months after discharge were included. Time-dependent multivariable Cox regression models adjusted for age, sex, patient characteristics, comorbidities, other medications, and year of SAVR were used. Primary outcome was a composite of all-cause mortality, myocardial infarction, and stroke. Subgroup analyses based on age, sex, heart failure, low ejection fraction, hyperlipidaemia, and hypertension were performed.

RESULTS

A total of 2,204 patients were included (median follow-up 5.0 years (range 0.0-11.5)). At baseline, 68% of the patients were dispensed RAS inhibitors, 80% beta-blockers, and 35% statins. Dispense of RAS inhibitors and beta-blockers declined over time, especially during the first year after baseline, while dispense of statins remained stable. Treatment with RAS inhibitors or statins was associated with a reduced risk of the primary outcome (aHR 0.71, 95%CI 0.57-0.87 and aHR 0.78, 95%CI 0.62-0.99, respectively). The results were consistent in subgroups based on age, sex, and comorbidities. Beta-blocker treatment was associated with an increased risk for the primary outcome (aHR 1.35, 95%CI 1.07-1.70).

CONCLUSIONS

The results indicate a potential beneficial association of RAS inhibitors and statins as part of a secondary preventive treatment regime after aortic valve replacement in patients with aortic regurgitation. The role of beta-blockers needs to be further investigated.

Risk factors and treatment of oxygenator high-pressure excursions during cardiopulmonary bypass

INTRODUCTION

A high-pressure excursion (HPE) is a sudden increase in oxygenator inlet pressure during cardiopulmonary bypass (CPB). The aims of this study were to identify factors associated with HPE, to describe a treatment protocol utilizing epoprostenol in severe cases, and to assess early outcome in HPE patients.

METHODS

Patients who underwent cardiac surgery with cardiopulmonary bypass at Sahlgrenska University Hospital 2016-2018 were included in a retrospective observational study. Pre- and post-operative data collected from electronic health records, local databases, and registries were compared between HPE and non-HPE patients. Factors associated with HPE were identified with logistic regression models.

RESULTS

In total, 2024 patients were analyzed, and 37 (1.8%) developed HPE. Large body surface area (adjusted Odds Ratio (aOR): 1.43 per 0.1 m²; 95% confidence interval (CI): 1.16-1.76, p < 0.001), higher hematocrit during CPB (aOR: 1.20 per 1%; (1.09-1.33), p < 0.001), acute surgery (aOR: 2.98; (1.26-6.62), p = 0.018), and previous stroke (aOR: 2.93; (1.03-7.20), p = 0.027) were independently associated with HPE. HPE was treated with hemodilution (n = 29, 78.4%), and/or extra heparin (n = 23, 62.2%), and/or epoprostenol (n = 12, 32.4%). No oxygenator change-out was necessary. While there was no significant difference in 30-day mortality (2.7% vs 3.2%, p = 1.0), HPE was associated with a higher perioperative stroke rate (8.1% vs 1.8%, aOR 5.09 (1.17-15.57), p = 0.011).

CONCLUSIONS

Large body surface area, high hematocrit during CPB, previous stroke and acute surgery were independently associated with HPE. A treatment protocol including epoprostenol appears to be a safe option. Perioperative stroke rate was increased in HPE patients.

Patients' motivation to undergo transcatheter aortic valve replacement. A phenomenological hermeneutic study

BACKGROUND

Aortic stenosis is the most common valvular disease, and its prevalence is increasing due to the ageing population. Transcatheter aortic valve replacement (TAVR) is the recommended method when treating frail, older patients. Knowledge of what motivates older patients to undergo TAVR is important, in order to meet patients' expectations.

OBJECTIVE

The study aimed to explore the meaning of older patients' motivation to undergo TAVR.

DESIGN AND METHODS

The design was a qualitative study, analysed using a phenomenological hermeneutic approach. In-depth, semi-structured interviews with open-ended questions were conducted. Participants were selected from a specialist cardiology clinic in Sweden. Eighteen patients, six women and twelve men, aged 66-92, were recruited.

RESULTS

The analysis showed that patients who had agreed to undergo TAVR were deeply affected by their body's failure. Before the TAVR procedure, the participants were limited in their daily activities and experienced that their life was on hold. They experienced that they were barely existing. They were aware of their life-threatening condition and were forced to confront death. Yet despite an advanced age, they still had considerable zest for life. It was very important to them to remain independent in everyday life, and fear of becoming dependent had a strong impact on their motivations for undergoing TAVR.

CONCLUSION

Older patients' motivations to undergo TAVR are strongly influenced by their fear of being dependent on others and their zest for life. Health care professionals need to support these patients in setting realistic and personalised goals.

IMPLICATION FOR PRACTICE

Person-centered care actions could facilitate patients' involvement in the decision about TAVR and strenghten patients' beliefs in their own capabilities, before and after TAVR.

Temperature effects on incidence of surgery for acute type A aortic dissection in the Nordics

We aimed to investigate a hypothesised association between daily mean temperature and the risk of surgery for acute type A aortic dissection (ATAAD). For the period of 1 January 2005 until 31 December 2019, we collected daily data on mean temperatures and date of 2995 operations for ATAAD at 10 Nordic cities included in the Nordic Consortium for Acute Type A Aortic Dissection (NORCAAD) collaboration. Using a two-stage time-series approach, we investigated the association between hot and cold temperatures relative to the optimal temperature and the rate of ATAAD repair in the selected cities. The relative risks (RRs) of cold temperatures (≤-5°C) and hot temperatures (≥21°C) compared to optimal temperature were 1.47 (95% CI: 0.72-2.99) and 1.43 (95% CI: 0.67-3.08), respectively. In line with previous studies, we observed increased risk at cold and hot temperatures. However, the observed associations were not statistically significant, thus only providing weak evidence of an association.

Impact of national holidays and weekends on incidence of acute type A aortic dissection repair

Previous studies have demonstrated that environmental and temporal factors may affect the incidence of acute type A aortic dissection (ATAAD). Here, we aimed to investigate the hypothesis that national holidays and weekends influence the incidence of surgery for ATAAD. For the period 1st of January 2005 until 31st of December 2019, we investigated a hypothesised effect of (country-specific) national holidays and weekends on the frequency of 2995 surgical repairs for ATAAD at 10 Nordic cities included in the Nordic Consortium for Acute Type A Aortic Dissection (NORCAAD) collaboration. Compared to other days, the number of ATAAD repairs were 29% (RR 0.71; 95% CI 0.54-0.94) lower on national holidays and 26% (RR 0.74; 95% CI 0.68-0.82) lower on weekends. As day of week patterns of symptom duration were assessed and the primary analyses were adjusted for period of year, our findings suggest that the reduced surgical incidence on national holidays and weekends does not seem to correspond to seasonal effects or surgery being delayed and performed on regular working days.

Perioperative stroke and survival in coronary artery bypass grafting patients: a SWEDEHEART study

OBJECTIVES

Perioperative stroke is a severe complication of cardiac surgery. We assessed the incidence of stroke over time, the association between stroke and mortality and identified preoperative factors independently associated with perioperative stroke, in a large nationwide cardiac surgery population.

METHODS

All patients who underwent coronary artery bypass grafting in Sweden 2006-2017 were included in a registry-based observational cohort study based on prospectively collected data. Multivariable logistic and Cox regression models were used to assess associations between perioperative stroke and mortality and to identify factors associated with stroke. The median follow-up was 6 years (range 0-12).

RESULTS

There were 441 perioperative strokes in 36 898 patients. The mean incidence was 1.2% and decreased marginally over time [adjusted odds ratio (OR) 0.97 per year (95% confidence interval 0.94-1.00), P = 0.035]. Stroke patients had a higher overall mortality risk during follow-up [adjusted hazard ratio 2.30 (2.00-2.64), P < 0.001], with the highest risk during the first 30 postoperative days [adjusted hazard ratio (7.29 (5.58-9.54), P < 0.001]. The strongest independent preoperative factors associated with stroke were prior cardiac surgery [adjusted OR 2.89 (1.40-5.96)], critical preoperative condition [adjusted OR 2.55 (1.73-3.76)], previous stroke [adjusted OR 1.77 (1.35-2.33)], preoperative angina requiring intravenous nitrates [adjusted OR 1.67 (1.28-2.17)], peripheral vascular disease [OR 1.63 (1.25-2.13)] and advanced age [OR 1.05 (1.03-1.06) per year].

CONCLUSIONS

The incidence of perioperative stroke after coronary artery bypass grafting has remained stable. Patients with perioperative stroke had a markedly higher adjusted risk of death early after surgery. The risk declined over time but remained higher during the entire follow-up period.

Beta blockers and long-term outcome after coronary artery bypass grafting: a nationwide observational study

Aims

Beta blockers are associated with improved outcomes for selected patients with cardiovascular disease. We assessed long-term utilization of beta blockers after coronary artery bypass grafting (CABG) and its association with outcome.

Methods and results

All 35 184 patients in Sweden who underwent first-time isolated CABG between 1 January 2006 and 31 December 2017 and were followed for at least 6 months were included in a nationwide observational study. Multivariable Cox regression models using time-updated data on dispensed prescriptions were used to assess associations between different types of beta blockers and outcomes. The primary outcome was major adverse cardiovascular events (MACEs), a composite of all-cause mortality, stroke, and myocardial infarction (MI). Subgroup analyses were performed in patients with and without previous MI, heart failure, and reduced left ventricular ejection fraction (LVEF). Median follow-up was 5.2 years (range 0–11). At baseline, 33 159 (94.2%) patients were dispensed beta blockers, 30 563 (92.2%) of which were cardioselective beta blockers. After 10 years, the dispensing of cardioselective beta blockers had declined to 73.7% of all patients. Ongoing treatment with cardioselective beta blockers was associated with a slight reduction in MACEs [hazard ratio (HR) 0.93, 95% confidence interval (CI) 0.89–0.98, P = 0.0063]. The reduction was largely driven by a reduced risk of MI (HR 0.83, 95% CI 0.75–0.92, P = 0.0003), while there was no significant reduction in all-cause mortality (HR 0.99, 95% CI 0.93–1.05) and stroke (HR 0.96, 95% CI 0.87–1.05). The reduced risk for MI was consistent in all the investigated subgroups.

Conclusion

Ongoing treatment with cardioselective beta blockers after CABG is associated with a reduction in MACEs, mainly because of reduced long-term risk for MI. The association between cardioselective beta blockers and MI was consistent in patients with and patients without previous MI, heart failure, atrial fibrillation, or reduced LVEF.

Human intracardiac SSEA4+CD34 cells show features of cycling, immature cardiomyocytes and are distinct from Side Population and C-kit+CD45- cells

Cardiomyocyte proliferation has emerged as the main source of new cardiomyocytes in the adult. Progenitor cell populations may on the other hand contribute to the renewal of other cell types, including endothelial and smooth muscle cells. The phenotypes of immature cell populations in the adult human heart have not been extensively explored. We therefore investigated whether SSEA4+CD34- cells might constitute immature cycling cardiomyocytes in the adult failing and non-failing human heart. The phenotypes of Side Population (SP) and C-kit+CD45- progenitor cells were also analyzed. Biopsies from the four heart chambers were obtained from patients with end-stage heart failure as well as organ donors without chronic heart failure. Freshly dissociated cells underwent flow cytometric analysis and sorting. SSEA4+CD34- cells expressed high levels of cardiomyocyte, stem cell and proliferation markers. This pattern resembles that of cycling, immature, cardiomyocytes, which may be important in endogenous cardiac regeneration. SSEA4+CD34- cells isolated from failing hearts tended to express lower levels of cardiomyocyte markers as well as higher levels of stem cell markers. C-kit+CD45- and SP CD45- cells expressed high levels of endothelial and stem cell markers–corresponding to endothelial progenitor cells involved in endothelial renewal.

pH-Dependent Protonation of Histidine Residues Is Critical for Electrostatic LDL (Low-Density Lipoprotein) Binding to Human Coronary Arteries

BACKGROUND

The initiating step in atherogenesis is the electrostatic binding of LDL (low-density lipoprotein) to proteoglycan glycosaminoglycans in the arterial intima. However, although proteoglycans are widespread throughout the intima of most coronary artery segments, LDL is not evenly distributed, indicating that LDL retention is not merely dependent on the presence of proteoglycans. We aim to identify factors that promote the interaction between LDL and the vessel wall of human coronary arteries.

METHODS

We developed an ex vivo model to investigate binding of human-labeled LDL to human coronary artery sections without the interference of cellular processes.

RESULTS

By staining consecutive sections of human coronary arteries, we found strong staining of sulfated glycosaminoglycans throughout the arterial intima, whereas endogenous LDL deposits were focally distributed. Ex vivo binding of LDL was uniform in all intimal areas with sulfated glycosaminoglycans. However, lowering the pH from 7.4 to 6.5 triggered a 35-fold increase in LDL binding. The pH-dependent binding was abolished by pretreating LDL with diethyl-pyrocarbonate, which blocks the protonation of histidine residues, or cyclohexanedione, which inhibits the positive charge of site B on LDL. Thus, both histidine protonation and site B are required for strong electrostatic LDL binding to the intima.

CONCLUSIONS

This study identifies histidine protonation as an important component for electrostatic LDL binding to human coronary arteries. Our findings show that the local pH will have a profound impact on LDL's affinity for sulfated glycosaminoglycans, which may influence the retention and accumulation pattern of LDL in the arterial vasculature.

Associations between medical therapy after surgical aortic valve replacement for aortic stenosis and long-term mortality: a report from the SWEDEHEART registry

AIMS

The association between the use of statins, renin-angiotensin system (RAS) inhibitors, and/or β-blockers and long-term mortality in patients with aortic stenosis (AS) who underwent surgical aortic valve replacement (SAVR) is unknown.

METHODS AND RESULTS

All patients with AS who underwent isolated first-time SAVR in Sweden from 2006 to 2017 and survived 6 months after discharge were included. Individual patient data from four mandatory nationwide registries were merged. Cox proportional hazards models, with time-updated data on medication status and adjusted for age, sex, comorbidities, type of prosthesis, and year of surgery, were used to investigate associations between dispensed statins, RAS inhibitors, and β-blockers and all-cause mortality. In total, 9553 patients were included, and the median follow-up time was 4.9 years (range 0-11); 1738 patients (18.2%) died during follow-up. Statins were dispensed to 49.1% and 49.0% of the patients within 6 months of discharge from the hospital and after 10 years, respectively. Corresponding figures were 51.4% and 53.9% for RAS inhibitors and 79.3% and 60.7% for β-blockers. Ongoing treatment was associated with lower mortality risk for statins {adjusted hazard ratio (aHR) 0.67 [95% confidence interval (95% CI) 0.60-0.74]; P < 0.001} and RAS inhibitors [aHR 0.84 (0.76-0.93); P < 0.001] but not for β-blockers [aHR 1.17 (1.05-1.30); P = 0.004]. The associations were robust in subgroups based on age, sex, and comorbidities (P for interactions >0.05).

CONCLUSIONS

The results of this large population-based real-world study support the use of statins and RAS inhibitors for patients who underwent SAVR due to AS.

Stroke Risk Stratification in Patients With Postoperative Atrial Fibrillation After Coronary Artery Bypass Grafting

Background

The CHA₂DS₂‐VASc (congestive heart failure, hypertension, age ≥75 years, diabetes, previous stroke or TIA [transient ischemic attack], vascular disease, age 65 to 74 years, sex category female; 2 indicates 2 points, otherwise 1 point) scoring system is recommended to guide decisions on oral anticoagulation therapy for stroke prevention in patients with nonsurgery atrial fibrillation. A score ≥1 in men and ≥2 in women, corresponding to an annual stroke risk exceeding 1%, warrants long‐term oral anticoagulation provided the bleeding risk is acceptable. However, in patients with new‐onset postoperative atrial fibrillation, the optimal risk stratification method is unknown. The aim of this study was therefore to evaluate the CHA₂DS₂‐VASc scoring system for estimating the 1‐year ischemic stroke risk in patients with new‐onset postoperative atrial fibrillation after coronary artery bypass grafting.

Methods and Results

All patients with new‐onset postoperative atrial fibrillation and without oral anticoagulation after first‐time isolated coronary artery bypass grafting performed in Sweden during 2007 to 2017 were eligible for this registry‐based observational cohort study. The 1‐year ischemic stroke rate at each step of the CHA₂DS₂‐VASc score was estimated using a Kaplan‐Meier estimator. Of the 6368 patients included (mean age, 69.9 years; 81% men), >97% were treated with antiplatelet drugs. There were 147 ischemic strokes during the first year of follow‐up. The ischemic stroke rate at 1 year was 0.3%, 0.7%, and 1.5% in patients with CHA₂DS₂‐VASc scores of 1, 2, and 3, respectively, and ≥2.3% in patients with a score ≥4. A sensitivity analysis, with the inclusion of patients on anticoagulants, was performed and supported the primary results.

Conclusions

Patients with new‐onset atrial fibrillation after coronary artery bypass grafting and a CHA₂DS₂‐VASc score <3 have such a low 1‐year risk for ischemic stroke that oral anticoagulation therapy should probably be avoided.

Data Mining Identifies CCN2 and THBS1 as Biomarker Candidates for Cardiac Hypertrophy

Cardiac hypertrophy is a condition that may contribute to the development of heart failure. In this study, we compare the gene-expression patterns of our in vitro stem-cell-based cardiac hypertrophy model with the gene expression of biopsies collected from hypertrophic human hearts. Twenty-five differentially expressed genes (DEGs) from both groups were identified and the expression of selected corresponding secreted proteins were validated using ELISA and Western blot. Several biomarkers, including CCN2, THBS1, NPPA, and NPPB, were identified, which showed significant overexpressions in the hypertrophic samples in both the cardiac biopsies and in the endothelin-1-treated cells, both at gene and protein levels. The protein-interaction network analysis revealed CCN2 as a central node among the 25 overlapping DEGs, suggesting that this gene might play an important role in the development of cardiac hypertrophy. GO-enrichment analysis of the 25 DEGs revealed many biological processes associated with cardiac function and the development of cardiac hypertrophy. In conclusion, we identified important similarities between ET-1-stimulated human-stem-cell-derived cardiomyocytes and human hypertrophic cardiac tissue. Novel putative cardiac hypertrophy biomarkers were identified and validated on the protein level, lending support for further investigations to assess their potential for future clinical applications.

Serum biomarkers of brain injury after uncomplicated cardiac surgery: Secondary analysis from a randomized trial

Background

Postoperative cognitive dysfunction is common after cardiac surgery. Postoperative measurements of brain injury biomarkers may identify brain damage and predict cognitive dysfunction. We describe the release patterns of five brain injury markers in serum and plasma after uncomplicated cardiac surgery.

Methods

Sixty‐one elective cardiac surgery patients were randomized to undergo surgery with either a dextran‐based prime or a crystalloid prime. Blood samples were taken immediately before surgery, and 2 and 24 h after surgery. Concentrations of the brain injury biomarkers S100B, glial fibrillary acidic protein (GFAP), tau, neurofilament light (NfL) and neuron‐specific enolase (NSE)) and the blood–brain barrier injury marker β‐trace protein were analyzed. Concentrations of brain injury biomarkers were correlated to patients’ age, operation time, and degree of hemolysis.

Results

No significant difference in brain injury biomarkers was observed between the prime groups. All brain injury biomarkers increased significantly after surgery (tau +456% (25th–75th percentile 327%−702%), NfL +57% (28%−87%), S100B +1145% (783%−2158%), GFAP +17% (−3%−43%), NSE +168% (106%−228%), while β‐trace protein was reduced (−11% (−17−3%). Tau, S100B, and NSE peaked at 2h, NfL and GFAP at 24 h. Postoperative concentrations of brain injury markers correlated to age, operation time, and/or hemolysis.

Conclusion

Uncomplicated cardiac surgery with cardiopulmonary bypass is associated with an increase in serum/plasma levels of all the studied injury markers, without signs of blood–brain barrier injury. The biomarkers differ markedly in their levels of release and time course. Further investigations are required to study associations between perioperative release of biomarkers, postoperative cognitive function and clinical outcome.

Risk of depression after coronary artery bypass grafting: a SWEDEHEART population-based cohort study

Aims

A diagnosis of depression in patients with coronary heart disease is associated with worse outcomes. This study examined the long-term risk for new onset of depression after coronary artery bypass grafting (CABG) compared to an age- and sex-matched control group from the general population.

Methods and results

In total, 125 418 primary isolated CABG patients and 495 371 matched controls were included from 1992 to 2017. The SWEDEHEART registry and three other national registers were used to acquire information about baseline characteristics and depression. The adjusted risk of depression was estimated by using Cox regression models adjusted for patient characteristics, and socioeconomic variables, described by hazard ratios (HR) and 95% confidence intervals (CI). In total, 6202 (4.9%) CABG patients and 17 854 (3.6%) controls developed depression. The cumulative incidence of depression was higher in CABG patients than in the control population [6.1%, 95% CI 6.0–6.3 vs. 4.7% (4.7–4.8), P < 0.0001]. Overall, the CABG group had a marginally increased adjusted risk of depression compared to controls [adjusted HR (aHR): 1.05 (1.01–1.09), P = 0.0091]. In age-specific analyses, the increased risk compared to controls was only present in patients <65 years [aHR: 1.19 (1.11–1.27), P <0.0001] and was only evident during the first 5 years after surgery.

Conclusion

Patients who underwent CABG had a higher risk of new onset of depression compared to sex- and age-matched controls in the general population. The risk of depression was especially pronounced in younger patients during the first 5 years after surgery.