Structural bioinformatics studies of six human ABC transporters and their AlphaFold2-predicted water-soluble QTY variants.

Human ATP-binding cassette (ABC) transporters are one of the largest families of membrane proteins and perform diverse functions. Many of them are associated with multidrug resistance that often results in cancer treatment with poor outcomes. Here, we present the structural bioinformatics study of six human ABC membrane transporters with experimentally determined cryo-electron microscopy (CryoEM) structures including ABCB7, ABCC8, ABCD1, ABCD4, ABCG1, ABCG5, and their AlphaFold2-predicted water-soluble QTY variants. In the native structures, there are hydrophobic amino acids such as leucine (L), isoleucine (I), valine (V), and phenylalanine (F) in the transmembrane alpha helices. These hydrophobic amino acids are systematically replaced by hydrophilic amino acids glutamine (Q), threonine (T), and tyrosine (Y). Therefore, these QTY variants become water soluble. We also present the superposed structures of native ABC transporters and their water-soluble QTY variants. The superposed structures show remarkable similarity with root mean square deviations between 1.064 and 3.413 Å despite significant (41.90-54.33%) changes to the protein sequence of the transmembrane domains. We also show the differences in hydrophobicity patches between the native ABC transporters and their QTY variants. We explain the rationale behind why the QTY membrane protein variants become water soluble. Our structural bioinformatics studies provide insight into the differences between the hydrophobic helices and hydrophilic helices and will likely further stimulate designs of water-soluble multispan transmembrane proteins and other aggregated proteins. The water-soluble ABC transporters may be useful as soluble antigens to generate therapeutic monoclonal antibodies for combating multidrug resistance in clinics.

Positive Correlation Between Thoracic Aortic Diameter and Intracranial Aneurysm Size-An Observational Cohort Study.

OBJECTIVE: To investigate the association between intracranial aneurysms (IAs) and thoracic aortic diameter. METHODS: This observational cohort study examined thoracic aortic diameters in patients with IA. Patients were categorized by IA size (<7 mm and ≥7 mm) and IA status (ruptured/unruptured) based on radiologic findings. We investigated the association between thoracic aortic diameter and IA size and status using binary and linear regression as univariate and multivariable analyses. RESULTS: A total of 409 patients were included. Mean age was 60 (±11.7) years and 63% were women. Thoracic aortic diameters were greater among patients who had an IA ≥7 mm versus IA <7 mm (P < 0.05). In the univariate analysis, the diameter of the ascending aorta (odds ratio [OR], 1.07; 95% confidence interval [CI], 1.02-1.129 per 1 mm; P = 0.002), aortic arch (OR, 1.10; 95% CI, 1.04-1.15 per 1 mm; P < 0.001), and descending aorta (OR, 1.10; 95% CI, 1.03-1.16 per 1 mm; P = 0.003) were associated with IAs ≥7 mm. In the multivariable regression model, larger ascending aorta (OR, 1.09; 95% CI, 1.01-1.17 per 1 mm; P = 0.018), aortic arch (OR, 1.12; 95% CI, 1.02-1.22 per 1 mm; P = 0.013), and descending aorta (OR, 1.20; 95% CI, 1.08-1.33 per 1 mm; P < 0.001) were associated with ruptured IA. CONCLUSIONS: Greater thoracic aortic diameters are associated with a higher risk of IA being larger than 7 mm and IA rupture. Exploring the concomitant growth tendency in IA and thoracic aorta provides a basis for future considerations regarding screening and risk management.

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.

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.

CrMP-Sol database: classification, bioinformatic analyses and comparison of cancer-related membrane proteins and their water-soluble variant designs.

Membrane proteins are critical mediators for tumor progression and present enormous therapeutic potentials. Although gene profiling can identify their cancer-specific signatures, systematic correlations between protein functions and tumor-related mechanisms are still unclear. We present here the CrMP-Sol database ( https://bio-gateway.aigene.org.cn/g/CrMP ), which aims to breach the gap between the two. Machine learning was used to extract key functional descriptions for protein visualization in the 3D-space, where spatial distributions provide function-based predictive connections between proteins and cancer types. CrMP-Sol also presents QTY-enabled water-soluble designs to facilitate native membrane protein studies despite natural hydrophobicity. Five examples with varying transmembrane helices in different categories were used to demonstrate the feasibility. Native and redesigned proteins exhibited highly similar characteristics, predicted structures and binding pockets, and slightly different docking poses against known ligands, although task-specific designs are still required for proteins more susceptible to internal hydrogen bond formations. The database can accelerate therapeutic developments and biotechnological applications of cancer-related membrane proteins.

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.

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.

Behavioral intervention grounded in motivational interviewing and behavioral economics shows promise with Black and English-speaking Latino persons living with HIV with unsuppressed HIV viral load in New York City: A mixed methods pilot study.

Introduction: Sustained HIV viral suppression is the ultimate goal of HIV treatment. African American/Black and Latino persons with HIV (PWH) in the United States are less likely than their White peers to achieve and sustain viral suppression. To address these disparities, we developed a "low-touch" behavioral intervention drawing on motivational interviewing and behavioral economics. The intervention had three main components: (1) a motivational interviewing counseling session, (2) 16 weeks of automated text messages and quiz questions about HIV management, where participants earned points by answering quiz questions, and 3) a lottery prize, based on viral suppression status, number of points earned, and chance (max. $275). Materials and methods: The intervention was tested in a pre-test/post-test design. The present pilot study used mixed methods to explore the intervention's feasibility, acceptability, impact, and ways it could be improved. Participants engaged in a baseline assessment, qualitative interview, and two structured follow-up assessments over an 8-month period, and provided laboratory reports to document HIV viral load. We carried out descriptive quantitative analyses. Qualitative data were analyzed using a directed content analysis approach. Data integration was carried out using the joint display method. Findings: Participants (N = 40) were 50 years old, on average (SD = 11), and approximately half (58%) were male. Close to two-thirds (68%) were African American/Black and 32% were Latino. Participants were diagnosed with HIV 22 years ago on average (SD = 8). The intervention was feasible (e.g., mean number of quiz questions answered = 13/16) and highly acceptable. While not powered to assess efficacy, the proportion with suppressed HIV viral load increased from baseline to follow-up (46% participants at the first, 52% participants at the second follow-up evidenced HIV viral suppression). In qualitative analyses, perspectives included that overall, the intervention was acceptable and useful, it was distinct from other programs, lottery prizes were interesting and appreciated but not sufficient to motivate behavior change, and the structure of lottery prizes was not sufficiently clear. Regarding data integration, qualitative data shed light on and extended quantitative results, and added richness and context. Conclusion: This low-touch intervention approach is sufficiently promising to warrant refinement and study in future research.

Once after a full moon: acute type A aortic dissection and lunar phases.

OBJECTIVES: Acute type A aortic dissection (ATAAD) is a rare but severe condition, routinely treated with emergent cardiac surgery. Many surgeons have the notion that patients with ATAAD tend to come in clusters, but no studies have examined these observations. This investigation was undertaken to study the potential association between the lunar cycle and the incidence of ATAAD. METHODS: We collected information on 2995 patients who underwent ATAAD surgery at centres from the Nordic Consortium for Acute Type A Aortic Dissection collaboration. We cross-referenced the time of surgery with lunar phase using a case-crossover design with 2 different definitions of full moon (>99% illumination and the 7-day full moon period). RESULTS: The period when the moon was illuminated the most (99% definition) did not show any significant increase in incidence for ATAAD surgery. However, when the full moon period was compared with all other moon phases, it yielded a relative risk of 1.08 [95% confidence interval (CI) 1.00-1.17, P = 0.057] and, compared to waxing moon, only the relative risk was 1.11 (95% CI 1.01-1.23, P = 0.027). The peak incidence came 4-6 days after the moon was fully illuminated. CONCLUSIONS: This study found an overrepresentation of surgery for ATAAD during the full moon phase. The explanation for this is not known, but we speculate that sleep deprivation during full moon leads to a temporary increase in blood pressure, which in turn could trigger rupture of the aortic wall. While this finding is interesting, it needs to be corroborated and the clinical implications are debateable.

Statins for secondary prevention and major adverse events after coronary artery bypass grafting.

OBJECTIVE: The objective of this study was to evaluate the association of statin use after coronary artery bypass grafting (CABG) and long-term adverse events in a large population-based, nationwide cohort. METHODS: All 35,193 patients who underwent first-time isolated CABG in Sweden from 2006 to 2017 and survived at least 6 months after surgery were included. Individual patient data from the Swedish Web System for Enhancement and Development of Evidence-Based Care in Heart Disease Evaluated According to Recommended Therapies (SWEDEHEART) and 4 other nationwide registries were merged. Multivariable Cox regression models adjusted for age, sex, comorbidities, and time-updated treatment with other secondary preventive medications were used to evaluate the associations between statin treatment and outcomes. The primary end point was major adverse cardiovascular events (MACE). Median follow-up time to MACE was 5.3 (interquartile range, 2.5-8.2) years. RESULTS: Statins were dispensed to 95.7% of the patients six months after discharge and to 78.9% after 10 years. At baseline, 1.4% of patients were prescribed low-, 57.6% intermediate-, and 36.7% high-dose statins. Ongoing statin treatment was associated with markedly reduced risk of MACE (adjusted hazard ratio [aHR], 0.56 [95% CI, 0.53-0.59]), all-cause mortality (aHR, 0.53 [95% CI, 0.50-0.56]), cardiovascular death (aHR, 0.54 [95% CI, 0.50-0.59]), myocardial infarction (aHR, 0.61 [95% CI, 0.55-0.69]), stroke (aHR, 0.66 [95% CI, 0.59-0.73]), new revascularization (aHR, 0.79 [95% CI, 0.70-0.88]), new angiography (aHR, 0.81 [95% CI, 0.74-0.88]), and dementia (aHR, 0.74 [95% CI, 0.65-0.85]; all P < .01), irrespective of the statin dose. CONCLUSIONS: Ongoing statin use was associated with a markedly reduced incidence of adverse events and mortality after CABG. Initiating and maintaining statin medication is essential in CABG patients.

Intravenous Interferon-ß1a for the Treatment of Ischemia-Reperfusion Injury in Acute Myocardial Infarct in Pigs.

BACKGROUND: To investigate the potential of intravenously administered porcine recombinant interferon-ß1a (IFN-ß1a) for myocardial protection during acute ischemia-reperfusion (IR) injury in an experimental animal model. METHODS: Twenty-two piglets (mean ± standard deviation, 26.7 ± 1.65 kg) were assigned to either the IFN group (n = 12) or the control group (n = 10). IR injury was induced by occluding the distal left descending coronary artery for 30 minutes, with a reperfusion period of 6 h. In the IFN group, the animals received 12.5 µg IFN-ß1a intravenously repeatedly; the control group received saline solution. The levels of interleukin-6 (IL-6) and cardiac troponin I (TnI) were measured, and the amount of myocardial damage was quantified by analyzing myocardial apoptosis and the mean fluorescence intensity (MFI) of methylene blue-stained cardiac tissue. RESULTS: In the IFN group, significantly more premature deaths occurred compared with the control group (25% versus 17%, P = .013). Between the groups, the mean heart rate was higher in the IFN group (102 ± 22 versus 80 ± 20 beats per minute, P = .02). IL-6 and TnI levels were comparable between the groups, with no significant difference, and there was no difference between the study groups in myocardial apoptosis in the infarcted myocardium. The percentage of MFI differed significantly between the IFN and control groups (90.75% ± 4.90% versus 96.02% ± 2.73%, P = .01). CONCLUSION: In this acute IR injury animal model, IFN-ß1a did not protect the myocardium from IR injury, but rather increased some of the unfavorable outcomes studied.

Stroke in acute type A aortic dissection: the Nordic Consortium for Acute Type A Aortic Dissection (NORCAAD).

OBJECTIVES: Stroke is a serious complication in patients with acute type A aortic dissection (ATAAD). Previous studies investigating stroke in ATAAD patients have been limited by small cohorts and have shown diverging results. We sought to identify risk factors for stroke and to evaluate the effect of stroke on outcomes in surgical ATAAD patients. METHODS: The Nordic Consortium for Acute Type A Aortic Dissection database included patients operated for ATAAD at 8 Scandinavian Hospitals between 2005 and 2014. RESULTS: Stroke occurred in 177 (15.7%) out of 1128 patients. Patients with stroke presented more frequently with cerebral malperfusion (20.6% vs 6.3%, P < 0.001), syncope (30.6% vs 17.6%, P < 0.001), cardiogenic shock (33.1% vs 20.7%, P < 0.001) and pericardial tamponade (25.9% vs 14.7%, P < 0.001) and more often underwent total aortic arch replacement (10.7% vs 4.7%, P = 0.016), compared to patients without stroke. In the 86 patients presenting with cerebral malperfusion, 38.4% developed stroke. Thirty-day and 5-year mortality in patients with and without stroke were 27.1% vs 13.6% and 42.9% vs 25.6%, respectively. Stroke was an independent predictor of early- [odds ratio 2.02, 95% confidence interval (CI) 1.34-3.05; P < 0.001] and midterm mortality (hazard ratio 1.68, 95% CI 1.27-2.23; P < 0.001). CONCLUSIONS: Stroke in ATAAD patients is associated with increased early- and midterm mortality. Preoperative cerebral malperfusion and impaired haemodynamics, as well as total aortic arch replacement, were more frequent among patients who developed stroke. Importantly, a large proportion of patients presenting with cerebral malperfusion did not develop a permanent stroke, indicating that signs of cerebral malperfusion should not be considered a contraindication for surgery.

ABO blood group does not impact incidence or outcomes of surgery for acute type A aortic dissection.

Objectives. To evaluate the distribution and impact of ABO blood groups on postoperative outcomes in patients undergoing surgery for acute type A aortic dissection (ATAAD). Design. A total of 1144 surgical ATAAD patients from eight Nordic centres constituting the Nordic consortium for acute type A aortic dissection (NORCAAD) were analysed. Blood group O patients were compared to non-O subjects. The relative frequency of blood groups was assessed with t-distribution, modified for weighted proportions. Multivariable logistic regression was performed to identify independent predictors of 30-day mortality. Cox regression analyses were performed for assessing independent predictors of late mortality. Results. There was no significant difference in the proportions of blood group O between the study populations in the NORCAAD registry and the background population (40.6 (95% CI 37.7-43.4)% vs 39.0 (95% CI 39.0-39.0)%). ABO blood group was not associated with any significant change in risk of 30-day or late mortality, with the exception of blood group A being an independent predictor of late mortality. Prevalence of postoperative complications was similar between the ABO blood groups. Conclusions. In this large cohort of Nordic ATAAD patients, there were no associations between ABO blood group and surgical incidence or outcomes, including postoperative complications and survival.

Outcome after type A aortic dissection repair in patients with preoperative cardiac arrest.

AIM OF THE STUDY: Patients presenting with acute type A aortic dissection (ATAAD) and cardiac arrest before surgery are considered to have very poor prognosis, but limited data is available. We used a large database to evaluate the outcome of ATAAD patients with a cardiac arrest before surgery. METHODS: We evaluated 1154 surgically treated ATAAD patients from the Nordic Consortium for Acute Type A Aortic Dissection (NORCAAD) database between 2005 and 2014. Patients with (n = 44, 3.8%) and without preoperative cardiac arrest were compared and variables univariably associated with mortality in the cardiac arrest group were identified. Median follow-up time was 2.7 years (interquartile range 0.5-5.5). RESULTS: Thirty-day mortality in the arrest and non-arrest group was 43.2% and 16.6%, respectively (odds ratio [OR] 3.83, CI 2.06-7.09; P < 0.001). In the nine patients with ongoing cardiopulmonary resuscitation when cardiopulmonary bypass was initiated, five died intraoperatively and one died after 65 days. In patients surviving the operation, stroke was significantly more common in the arrest group (48.4% vs 18.2%; OR 4.21, CI 2.05-8.67; P < 0.001). In total, 50.0% (22/44) of the arrest patients survived to the end of follow-up. Non-survivors in the arrest group more often had DeBakey type I dissection, cardiac tamponade, cardiac malperfusion and higher preoperative serum lactate (all P < 0.05). CONCLUSIONS: Early mortality and complications after ATAAD surgery in patients with a preoperative cardiac arrest are high, but mid-term outcome after surviving the initial period is acceptable. Preoperative cardiac arrest should not be considered an absolute contraindication for a surgical ATAAD repair.

Prevalence of thoracic aortic aneurysms and dilatations in patients with intracranial aneurysms.

OBJECTIVE: The prevalence of intracranial aneurysms (IAs) is higher in patients with aortic aneurysms. However, there are lack of studies investigating prevalence of thoracic aortic aneurysms (TAAs) in patients with IAs. The objective of this study was to evaluate the prevalence and risk factors for thoracic aortic dilatations (TADs) and TAAs in patients with IAs. METHODS: We retrospectively reviewed data from 1777 patients with diagnosed IAs at our institution between 2006 and 2016. We included 411 patients with saccular IAs and available imaging studies (computed tomography or magnetic resonance imaging) of all thoracic aortic segments. TAD was defined according to age- and sex-matched normograms, and TAA as a diameter of greater than 4.0 cm. RESULTS: A total of 83 patients (20%) had TAD or TAA. The prevalence of TADs and TAAs were 18% (n = 74) and 8% (n = 31) without significant difference between unruptured and ruptured IAs (P = .7). Of the 74 patients with TAD, 22 (30%) had multiple TADs and 66% of the TADs located in the aortic arch. Older age (odds ratio [OR], 1.04; P = .006), rheumatic disease (OR, 4.73; P = .009) and alcohol abuse (OR, 4.77; P = .01) were significant risk factors for TAD/TAA. CONCLUSIONS: The prevalence of TADs and TAAs is considerably greater in patients with IAs compared with reports from the general population, suggesting that IAs might be associated with aortopathy and might share a similar pathogenetic background with TADs/TAAs. Especially patients with IAs and a history of rheumatic disease and/or alcohol abuse are at high risk for TADs/TAAs.

Is There a Weekend Effect in Surgery for Type A Dissection?: Results From the Nordic Consortium for Acute Type A Aortic Dissection Database.

BACKGROUND: Aortic dissection type A requires immediate surgery. In general surgery populations, patients operated on during weekends have higher mortality rates compared with patients whose operations occur on weekdays. The weekend effect in aortic dissection type A has not been studied in detail. METHODS: The Nordic Consortium for Acute Type A Aortic Dissection (NORCAAD) registry includes data for 1,159 patients who underwent type A dissection surgery at 8 Nordic centers during 2005 to 2014. This study is based on data relating to surgery conducted during weekdays versus weekends and starting between 8:00 am and 8:00 pm ("daytime") versus from 8:00 pm to 8:00 am ("nighttime"), as well as time from symptoms, admittance, and diagnosis to surgery. The influence of timing of surgery on the 30-day mortality rate was assessed using logistic regression analysis. RESULTS: The 30-day mortality was 18% (204 of 1,159), with no difference in mortality between surgery performed on weekdays (17% [150 of 889]) and on weekends (20% [54 of 270], p = 0.45), or during nighttime (19% [87 of 467]) versus daytime (17% [117 of 680], p = 0.54). Time from symptoms to surgery (median 7.0 hours vs 6.5 hours, p = 0.31) did not differ between patients who survived and those who died at 30 days. Multivariable regression analysis of risk factors for 30-day mortality showed no weekend effect (odds ratio, 1.04; 95% confidence interval, 60.67 to 1.60; p = 0.875), but nighttime surgery was a risk factor (odds ratio, 2.43; 95% confidence interval, 1.29 to 4.56; p = 0.006). CONCLUSIONS: The 30-day mortality in surgical repair of aortic dissection type A was not significantly affected by timing of surgery during weekends versus weekdays. Nighttime surgery seems to predict increased 30-day mortality, after correction for other risk factors.

A single sequential snake saphenous vein graft versus separate left and right vein grafts in coronary artery bypass surgery: a population-based cohort study from the SWEDEHEART registry†.

OBJECTIVES: Our goal was to compare short- and midterm outcomes after coronary artery bypass grafting (CABG) using 2 different revascularization strategies. METHODS: A total of 6895 patients were included who had CABG in Sweden from 2009 to 2015 using the left internal mammary artery to the left anterior descending artery and either a single sequential saphenous vein graft connecting the left and right coronary territories to the aorta (snake graft, n = 2122) or separate vein grafts to both territories (n = 4773). Data were obtained from the Swedish Web System for Enhancement of Evidence-Based Care in Heart Disease Evaluated According to Recommended Therapies (SWEDEHEART) and the Swedish Patient Registry. The groups were compared using adjusted logistic regression for short-term (30-day) and Cox regression and flexible parametric survival models for midterm outcomes. Primary outcome was a composite of all-cause mortality, myocardial infarction (MI), reangiography and new revascularization. The median follow-up time was 35 months. RESULTS: At 30 days, the incidences of the composite end point [odds ratio (OR) 1.31, 95% confidence interval (CI) 1.03-1.68; P = 0.03] and reangiography (OR 1.51, 95% CI 1.07-2.14; P = 0.02) were higher in the snake group. There was also a trend towards higher mortality (OR 1.47, 95% CI 0.97-2.22; P = 0.07). The event rates during the complete follow-up period were 6.5 (5.9-7.2) and 5.7 (5.3-6.1) per 100 person-years for the snake group and the separate vein group, respectively. At the midterm follow-up, no significant difference between the groups could be shown for the composite end point [hazard ratio (HR) 1.08, 95% CI 0.95-1.22; P = 0.24], mortality (HR 0.95, 95% CI 0.79-1.14; P = 0.56), MI (HR 1.11, 95% CI 0.88-1.41; P = 0.39) or new revascularization (HR 1.19, 95% CI 0.94-1.50; P = 0.15), whereas reangiography remained more common in the snake group (HR 1.25, 95% CI 1.05-1.48; P = 0.01). CONCLUSIONS: Snake grafts were associated with a higher rate of early postoperative complications, possibly reflecting a more demanding surgical technique, whereas midterm outcomes were comparable. Based on these data, one strategy cannot be recommended over the other.

Potential effects of low-dose average CT on cardiac implantable electronic devices.

BACKGROUND: Average CT has been shown to be more accurate than conventional helical CT in quantitation of the PET data. The risk of CT irradiation of a cardiac implantable electronic device (CIED) causing an adverse event is low and is generally outweighed by the clinical benefit of a medically indicated examination. However, irradiation of CIED over one breath cycle in cine CT scan for average CT could impose risks on a patient who is pacing dependent. The purpose of this study was to demonstrate that low-dose average CT can be safe for CIED. METHODS: A Medtronic CIED of model Protecta VR was submerged in a saline bath for a series of 4-s cine CT scans on a GE CT scanner programmed to deliver a 2-cm-wide radiation at a dose rate of 0.9 to 41.2 mGy/s to the CIED. The number of over-sensings was recorded as the interference of radiation to the CIED. RESULTS: Dose rates ≥ 1.9 mGy/s caused over-sensing. The higher the dose rate, the more over-sensings there were. The lowest dose rate of 0.9 mGy/s did not cause any over-sensing. CONCLUSIONS: Low-dose average CT at 0.9 mGy/s can be safe for a CIED patient who is pacing dependent.

Malperfusion in acute type A aortic dissection: An update from the Nordic Consortium for Acute Type A Aortic Dissection.

OBJECTIVES: To evaluate the effect of preoperative malperfusion on 30-day and late mortality and postoperative complications using data from the Nordic Consortium for Acute Type A Aortic Dissection (ATAAD) registry. METHODS: We studied 1159 patients who underwent ATAAD surgery between January 2005 and December 2014 at 8 Nordic centers. Multivariable logistic and Cox regression analyses were performed to identify independent predictors of 30-day and late mortality. RESULTS: Preoperative malperfusion was identified in 381 of 1159 patients (33%) who underwent ATAAD surgery. Thirty-day mortality was 28.9% in patients with preoperative malperfusion and 12.1% in those without. Independent predictors of 30-day mortality included any malperfusion (odds ratio, 2.76; 95% confidence interval [CI], 1.94-3.93), cardiac malperfusion (odds ratio, 2.37; 95% CI, 1.34-4.17), renal malperfusion (odds ratio, 2.38; 95% CI, 1.23-4.61) and peripheral malperfusion (odds ratio, 1.95; 95% CI, 1.26-3.01). Any malperfusion (hazard ratio, 1.72; 95% CI, 1.21-2.43), cardiac malperfusion (hazard ratio, 1.89; 95% CI, 1.24-2.87) and gastrointestinal malperfusion (hazard ratio, 2.25; 95% CI, 1.18-4.26) were predictors of late mortality. Malperfusion was associated with significantly poorer survival at 1, 3, and 5 years (95.0% ± 0.9% vs 88.7% ± 1.9%, 90.1% ± 1.3% vs 84.0% ± 2.4%, and 85.4% ± 1.7% vs 80.8% ± 2.7%; log rank P = .009). CONCLUSIONS: Malperfusion has a significant influence on early and late outcomes in ATAAD surgery. Management of preoperative malperfusion remains a major challenge in reducing mortality associated with surgical treatment of ATAAD.

Low rate of reoperations after acute type A aortic dissection repair from The Nordic Consortium Registry.

OBJECTIVES: To describe the relationship between the extent of primary aortic repair and the incidence of reoperations after surgery for type A aortic dissection. METHODS: A retrospective cohort of 1159 patients treated for type A aortic dissection at eight Nordic low- to medium-sized cardiothoracic centers from 2005 to 2014. Data were gathered from patient records and national registries. Patients were separately divided into 3 groups according to the distal anastomoses technique (ascending aorta [n = 791], hemiarch [n = 247], and total arch [n = 66]), and into 2 groups for proximal repair (aortic root replacement [n = 285] and supracoronary repair [n = 832]). Freedom from reoperation was estimated with cumulative incidence survival and Fine-Gray competing risk regression model was used to identify independent risk factors for reoperation. RESULTS: The median follow-up was 2.7 years (range, 0-10 years). Altogether 51 out of 911 patients underwent reoperation. Freedom from distal reoperation at 5 years was 96.9%, with no significant difference between the groups (P = .22). Freedom from proximal reoperation at 5 years was 97.8%, with no difference between the groups (P = .84). Neither DeBakey classification nor the extent of proximal or distal repair predicted freedom from a later reoperation. The only independent risk factor associated with a later proximal reoperation was a history of connective tissue disease. CONCLUSIONS: Type A aortic dissection repair in low- to medium-volume centers was associated with a low reoperation rate and satisfactory midterm survival. The extent of the primary repair had no significant influence on reoperation rate or midterm survival.