Comparative Long-Term Clinical Performance of Mechanical Aortic Valve Prostheses

Importance

Aggregated data and long-term follow-up in national health data registers offer the opportunity to compare the performance of mechanical aortic prostheses within the same population.

Objective

To investigate the clinical performance of mechanical aortic valve prostheses.

Design, Setting, and Participants

This nationwide cohort study included all 5224 patients who underwent primary mechanical aortic valve replacement in Sweden between January 1, 2003, and December 31, 2018. Statistical analysis was performed between May and September 2023.

Exposures

Surgical aortic valve replacement with the On-X, Carbomedics, Bicarbon, Standard, Regent, Open Pivot, Masters, or Advantage valve models.

Main Outcomes and Measures

The primary outcome was all-cause mortality, and secondary outcomes were reintervention, heart failure, major bleeding, stroke, and embolic events. Regression standardization was used to account for baseline differences.

Results

Overall, 5224 patients (mean [SD] age, 56.8 [11.7] years; 3908 men [74.8%]) were included. Total follow-up time was 43 982 person-years (mean [SD], 8.4 [4.6] years; maximum, 17.2 years). After regression standardization, there was a significant difference in 10-year mortality between the Carbomedics model group (17%; 95% CI, 15%-18%), Regent model group (17%; 95% CI, 13%-20%), and Standard model group (17%; 95% CI, 14%-19%) compared with the Bicarbon model group (27%; 95% CI, 21%-34%).

Conclusions and Relevance

In this cohort study of mechanical valve surgical aortic replacement outcomes in Sweden, the rate of all-cause mortality was higher in the Bicarbon group than in the Carbomedics, Regent, and Standard model groups. These findings warrant further research on the long-term clinical performance of the Bicarbon valve.

Prosthetic Valve Endocarditis After Aortic Valve Replacement With Bovine Versus Porcine Bioprostheses

BACKGROUND

Whether a bovine or porcine aortic valve bioprosthesis carries a higher risk of endocarditis after aortic valve replacement is unknown. The aim of this study was to compare the risk of prosthetic endocarditis in patients undergoing aortic valve replacement with a bovine versus porcine bioprosthesis.

METHODS AND RESULTS

This nationwide, population-based cohort study included all patients who underwent surgical aortic valve replacement with a bovine or porcine bioprosthesis in Sweden from 1997 to 2018. Regression standardization was used to account for intergroup differences. The primary outcome was prosthetic valve endocarditis, and the secondary outcomes were all-cause mortality and early prosthetic valve endocarditis. During a maximum follow-up time of 22 years, we included 21 022 patients, 16 603 with a bovine valve prosthesis and 4419 with a porcine valve prosthesis. The mean age was 73 years, and 61% of the patients were men. In total, 910 patients were hospitalized for infective endocarditis: 690 (4.2%) in the bovine group and 220 (5.0%) in the porcine group. The adjusted cumulative incidence of prosthetic valve endocarditis at 15 years was 9.5% (95% CI, 6.2%-14.4%) in the bovine group and 2.8% (95% CI, 1.4%-5.6%) in the porcine group. The absolute risk difference between the groups at 15 years was 6.7% (95% CI, 0.8%-12.5%).

CONCLUSIONS

The risk of endocarditis was higher in patients who received a bovine compared with a porcine valve prosthesis after surgical aortic valve replacement. This association should be considered in patients undergoing both surgical and transcatheter aortic valve replacement.

Exploratory Multisite MR Spectroscopic Imaging Shows White Matter Neuroaxonal Loss Associated with Complications of Type 1 Diabetes in Children

BACKGROUND AND PURPOSE

Type 1 diabetes affects over 200,000 children in the United States and is associated with an increased risk of cognitive dysfunction. Prior single-site, single-voxel MRS case reports and studies have identified associations between reduced NAA/Cr, a marker of neuroaxonal loss, and type 1 diabetes. However, NAA/Cr differences among children with various disease complications or across different brain tissues remain unclear. To better understand this phenomenon and the role of MRS in characterizing it, we conducted a multisite pilot study.

MATERIALS AND METHODS

In 25 children, 6-14 years of age, with type 1 diabetes across 3 sites, we acquired T1WI and axial 2D MRSI along with phantom studies to calibrate scanner effects. We quantified tissue-weighted NAA/Cr in WM and deep GM and modeled them against study covariates.

RESULTS

We found that MRSI differentiated WM and deep GM by NAA/Cr on the individual level. On the population level, we found significant negative associations of WM NAA/Cr with chronic hyperglycemia quantified by hemoglobin A1c (P < .005) and a history of diabetic ketoacidosis at disease onset (P < .05). We found a statistical interaction (P < .05) between A1c and ketoacidosis, suggesting that neuroaxonal loss from ketoacidosis may outweigh that from poor glucose control. These associations were not present in deep GM.

CONCLUSIONS

Our pilot study suggests that MRSI differentiates GM and WM by NAA/Cr in this population, disease complications may lead to neuroaxonal loss in WM in children, and deeper investigation is warranted to further untangle how diabetic ketoacidosis and chronic hyperglycemia affect brain health and cognition in type 1 diabetes.

Effect of Prosthesis-Patient Mismatch on Long-Term Clinical Outcomes After Bioprosthetic Aortic Valve Replacement

BACKGROUND

Prosthesis-patient mismatch (PPM) is common following surgical aortic valve replacement (SAVR).

OBJECTIVES

The purpose of this study was to quantify the impact of PPM on all-cause mortality, heart failure hospitalization, and reintervention following bioprosthetic SAVR.

METHODS

This observational nationwide cohort study from SWEDEHEART (Swedish Web system for Enhancement and Development of Evidence based care in Heart disease Evaluated According to Recommended Therapies) and other national registers included all patients who underwent primary bioprosthetic SAVR in Sweden from 2003 to 2018. PPM was defined according to the Valve Academic Research Consortium 3 criteria. Outcomes were all-cause mortality, heart failure hospitalization, and aortic valve reintervention. Regression standardization was used to account for intergroup differences and to estimate cumulative incidence differences.

RESULTS

We included 16,423 patients (no PPM: 7,377 [45%]; moderate PPM: 8,502 [52%]; and severe PPM: 544 [3%]). After regression standardization, the cumulative incidence of all-cause mortality at 10 years was 43% (95% CI: 24%-44%) in the no PPM group compared with 45% (95% CI: 43%-46%) and 48% (95% CI: 44%-51%) in the moderate and severe PPM groups, respectively. The survival difference at 10 years was 4.6% (95% CI: 0.7%-8.5%) and 1.7% (95% CI: 0.1%-3.3%) in no vs severe PPM and no vs moderate PPM, respectively. The difference in heart failure hospitalization at 10 years was 6.0% (95% CI: 2.2%-9.7%) in severe vs no PPM. There was no difference in aortic valve reintervention in patients with or without PPM.

CONCLUSIONS

Increasing grades of PPM were associated with long-term mortality, and severe PPM was associated with increased heart failure. Moderate PPM was common, but the clinical significance may be negligible because the absolute risk differences in clinical outcomes were small.

Surgery for endocarditis in patients with bicuspid aortic valves

Background

The objective of this study is to investigate clinical outcomes in patients with bicuspid aortic valves (BAV) after surgical treatment for endocarditis.

Methods

This was a population-based, observational cohort study, conducted on all patients who received aortic valve surgery for native or prosthetic valve endocarditis at Karolinska University Hospital between 2002–2020. Baseline characteristics and postoperative complications were collected from the institutional surgical database and patient medical charts. The primary endpoint was all-cause mortality. We used unadjusted and adjusted Cox regression to determine the association between valve morphology and long-term mortality.

Results

Of the 338 patients, 122 (36%) had a BAV and 216 (64%) had a tricuspid aortic valve (TAV). The mean follow-up was 5.8 years (maximum 18.4 years). Survival rates at one, five, ten and 14 years were 88%, 81%, 78% and 76% versus 85%, 69%, 58% and 43%, in BAV and TAV patients, respectively [adjusted hazard ratio (HR) 0.64; 95% confidence interval (CI): 0.39–1.05]. In patients with native valve endocarditis, those with BAV had lower all-cause mortality compared to those with TAV (adjusted HR 0.44; 95% CI: 0.22–0.89), despite having a higher prevalence of perivalvular abscess (40% versus 22%, respectively, in BAV and TAV patients). In patients with prosthetic valve endocarditis, original valve morphology did not affect all-cause mortality (adjusted HR 1.94; 95% CI: 0.64–5.87).

Conclusions

In patients with native valve endocarditis, a BAV was associated with improved survival after surgical treatment. In patients with prosthetic valve endocarditis, survival was not affected by the original valve morphology of the patient.

Socioeconomic Status and Risk of Bleeding After Mechanical Aortic Valve Replacement

BACKGROUND

Whether low socioeconomic status (SES) is associated with increased risk of anticoagulation-related adverse events in patients with mechanical heart valves is unknown.

OBJECTIVES

This study sought to investigate the impact of patients' SES on the risk of bleeding after mechanical aortic valve replacement (AVR).

METHODS

This nationwide population-based cohort study included all patients aged 18-70 years who underwent mechanical AVR in Sweden from 1997 to 2018. Data were obtained from the SWEDEHEART register and other national health data registers. The exposure was quartiles of household disposable income. The primary outcome was hospitalization for a bleeding event.

RESULTS

Among 5974 patients, the absolute risk for bleeding after 20 years of follow-up was 20% (95% CI: 17%-24%) in the lowest income quartile (Q1) and 16% (95% CI: 13%-20%) in the highest quartile (Q4). The risk of bleeding decreased with increasing income level and was significantly lower in patients in income level Q3 (HR: 0.77; 95% CI: 0.60-0.99) and Q4 (HR: 0.68; 95% CI: 0.50-0.92) than Q1. The risk of death from intracranial hemorrhage was five times higher in the lowest income quartile than the age- and sex-matched general Swedish population (standardized mortality ratio: 5.0; 95% CI: 3.3-7.4).

CONCLUSIONS

We observed a strong association between SES and risk of bleeding among patients who underwent mechanical AVR. These findings suggest suboptimal anticoagulation treatment in patients with lower SES and the need for strategies to optimize anticoagulation treatment in patients with a mechanical heart valve. (Health-Data Register Studies of Risk and Outcomes in Cardiac Surgery [HARTROCS]; NCT02276950).

Comparison of Long-term Performance of Bioprosthetic Aortic Valves in Sweden From 2003 to 2018

IMPORTANCE

The performance of bioprosthetic aortic valves is usually assessed in single valve models or head-to-head comparisons. National databases or registries offer the opportunity to investigate all available valve models in the population and allows for a comparative assessment of their performance.

OBJECTIVE

To analyze the long-term rates of reintervention, all-cause mortality, and heart failure hospitalization associated with commonly used bioprosthetic aortic valves and to identify valve model groups with deviation in clinical performance.

DESIGN, SETTING, AND PARTICIPANTS

This population-based, nationwide cohort study included all adult patients who underwent surgical aortic valve replacement (with or without concomitant coronary artery bypass surgery or ascending aortic surgery) in Sweden between January 1, 2003, and December 31, 2018. Patients were identified from the SWEDEHEART (Swedish Web-System for Enhancement and Development of Evidence-Based Care in Heart Disease Evaluated According to Recommended Therapies) registry. Patients with concomitant valve surgery, previous cardiac surgery, and previous transcatheter valve replacement were excluded. Follow-up was complete for all participants. Data were analyzed from March 9, 2020, to October 12, 2021.

EXPOSURES

Primary surgical aortic valve replacement with the Perimount, Mosaic/Hancock, Biocor/Epic, Mitroflow/Crown, Soprano, and Trifecta valve models.

MAIN OUTCOMES AND MEASURES

The primary outcome was cumulative incidence of reintervention, defined as a subsequent aortic valve operation or transcatheter valve replacement. Secondary outcomes were all-cause mortality and heart failure hospitalization. Regression standardization and flexible parametric survival models were used to account for intergroup differences. Mean follow-up time was 7.1 years, and maximum follow-up time was 16.0 years.

RESULTS

A total of 16 983 patients (mean [SD] age, 72.6 [8.5] years; 10 685 men [62.9%]) were included in the analysis. The Perimount valve model group had the lowest and the Mitroflow/Crown valve model group had the highest cumulative incidence of reintervention. The estimated cumulative incidence of reintervention at 10 years was 3.6% (95% CI, 3.1%-4.2%) in the Perimount valve model group and 12.2% (95% CI, 9.8%-15.1%) in the Mitroflow/Crown valve model group. The estimated incidence of reintervention at 10 years was 9.3% (95% CI, 7.3%-11.3%) in the Soprano valve model group.

CONCLUSIONS AND RELEVANCE

Results of this study showed that the Perimount valve was the most commonly used and had the lowest incidence of reintervention, all-cause mortality, and heart failure hospitalization, whereas the Mitroflow/Crown valve had the highest rates. These findings highlight the need for clinical vigilance in patients who receive either a Soprano or Mitroflow/Crown aortic bioprosthesis.

Permanent pacemaker implantation after On-X surgical aortic valve replacement: SWEDEHEART observational study

OBJECTIVE

Bioprosthetic aortic valves with an extended subannular component, such as transcatheter valves, exert increased compression on the cardiac conduction system and increase the risk for permanent pacemaker implantation. It is unknown if the On-X mechanical prosthetic valve, which has an elongated subannular valve housing, increases the risk of permanent pacemaker implantation following aortic valve replacement.

DESIGN

Observational nationwide cohort study.

SETTING

Swedish population-based study.

PARTICIPANTS

All patients aged 18-65 years who underwent primary mechanical aortic valve replacement in Sweden between 2005 and 2018. We used the Swedish Web system for Enhancement and Development of Evidence-based care in Heart disease Evaluated According to Recommended Therapies register and other Swedish national health-data registers.

EXPOSURE

Patients implanted with an On-X valve versus patients implanted with other bileaflet mechanical valves.

PRIMARY AND SECONDARY OUTCOME MEASURES

Primary outcome measure was permanent pacemaker implantation within 30 days of surgery.

RESULTS

A total of 2602 patients were included, and 581 patients received an On-X valve and 2021 patients received a St Jude Masters/Regent (n=945) or Carbomedics Reduced valve (n=1076). In the total study population, 115 (4.4%) permanent pacemaker implantations were performed within 30 days after aortic valve replacement. In the propensity score matched population, there was no significant difference in the rate of permanent pacemaker implantation in the On-X group compared with the control group: 3.6% (95% CI: 2.4% to 5.5%) vs 4.0% (95% CI: 2.7% to 5.9%), p=0.877.

CONCLUSIONS

The On-X prosthetic heart valve was associated with a similarly low risk for permanent pacemaker implantation after aortic valve replacement compared with other conventional bileaflet mechanical valves. The On-X elongated subannular valve housing does not interfere with the cardiac conduction system.

Cause of Death After Surgical Aortic Valve Replacement: SWEDEHEART Observational Study

Background

Prior studies showed that life expectancy in patients who underwent surgical aortic valve replacement (AVR) was lower than in the general population. Explanations for this shorter life expectancy are unknown. The aim of this nationwide, observational cohort study was to investigate the cause‐specific death following surgical AVR.

Methods and Results

We included 33 018 patients who underwent primary surgical AVR in Sweden between 1997 and 2018, with or without coronary artery bypass grafting. The SWEDEHEART (Swedish Web‐System for Enhancement and Development of Evidence‐Based Care in Heart Disease Evaluated According to Recommended Therapies) register and other national health‐data registers were used to obtain and characterize the study cohort and to identify causes of death, categorized as cardiovascular mortality, cancer mortality, or other causes of death. The relative risks for cause‐specific mortality in patients who underwent AVR compared with the general population are presented as standardized mortality ratios. During a mean follow‐up period of 7.3 years (maximum 22.0 years), 14 237 (43%) patients died. The cumulative incidence of death from cardiovascular, cancer‐related, or other causes was 23.5%, 8.3%, and 11.6%, respectively, at 10 years, and 42.8%, 12.8%, and 23.8%, respectively, at 20 years. Standardized mortality ratios for cardiovascular, cancer‐related, and other causes of death were 1.79 (95% CI, 1.75–1.83), 1.00 (95% CI, 0.97–1.04), and 1.08 (95% CI, 1.05–1.12), respectively.

Conclusions

We found that life expectancy following AVR was lower than in the general population. Lower survival after AVR was explained by an increased relative risk of cardiovascular death. Future studies should focus on the role of earlier surgery in patients with asymptomatic aortic stenosis and on optimizing treatment and follow‐up after AVR.

Registration

URL: https://www.clinicaltrials.gov; Unique identifier: NCT02276950.

Transcatheter aortic valve replacement using the iSleeve expandable sheath in small femoral arteries

Background

Small femoral arteries have been associated with a higher risk of vascular complications in transfemoral transcatheter aortic valve replacement (TAVR). We investigated the feasibility and safety of TAVR in patients with small femoral arteries.

Methods

In this observational study, we included 82 patients who underwent transfemoral TAVR with the ACURATE neo system using the expandable 14F iSleeve sheath between 2018 and 2019 at Karolinska University Hospital, Sweden. Of these, 41 patients had a minimal femoral artery diameter of ≥5.5 mm (mean 6.5, range 5.5–9.2), and 41 patients had a minimal femoral artery diameter <5.5 mm (mean 4.9, range 3.9–5.4).

Results

There was no significant difference in major vascular and bleeding complications between the small femoral artery group (7%) and the normal femoral artery group (2%) (p=0.62). The total of major and minor vascular complications did not differ significantly according to femoral artery size (17% vs 5%) (p=0.16). The iSleeve sheath was not correlated with any of the complications. The use of the iSleeve sheath was unsuccessful in four patients (5%), of which one patient had a small femoral artery diameter.

Conclusion

Transfemoral TAVR with the ACURATE neo system using the iSleeve sheath is a promising method for patients with small femoral arteries even though we found a trend towards higher rates of complications in these patients. The use of expandable sheaths may expand the spectrum of patients that can be treated with transfemoral TAVR, and thus may improve the prognosis in patients with severe aortic valve stenosis.

Outcomes Following Permanent Pacemaker Implantation After Transcatheter Aortic Valve Replacement: SWEDEHEART Observational Study

OBJECTIVES

This study was performed to investigate long-term, clinically important outcomes in patients who underwent permanent pacemaker implantation after transcatheter aortic valve replacement (TAVR).

BACKGROUND

The impact of permanent pacemaker implantation after TAVR is unknown, and prior studies have produced conflicting results.

METHODS

In this nationwide, population-based cohort study, the study included all patients who underwent transfemoral TAVR in Sweden from 2008 to 2018 from the SWEDEHEART (Swedish Web-system for Enhancement and Development of Evidence-based care in Heart disease Evaluated According to Recommended Therapies) register. Additional baseline characteristics and information about outcomes were obtained by individual crosslinking with other national health data registers. Unadjusted and multivariable-adjusted analyses were performed using Cox proportional hazards regression.

RESULTS

Of 3,420 patients, 481 (14.1%) underwent permanent pacemaker implantation within 30 days after TAVR. The survival rate at 1, 5, and 10 years was 90.0%, 52.7%, and 10.9% in the pacemaker group and 92.7%, 53.8%, and 15.3% in the nonpacemaker group, respectively (HR: 1.03; 95% CI: 0.88-1.22; P = 0.692). The median follow-up was 2.7 years (interquartile range: 2.5, and maximum 11.8 years). There was no difference in the risk of cardiovascular death (HR: 0.91; 95% CI: 0.71-1.18; P = 0.611), heart failure (HR: 1.23; 95% CI: 0.92-1.63; P = 0.157), or endocarditis (HR: 0.90; 95% CI: 0.47-1.69; P = 0.734) between the groups.

CONCLUSIONS

The study found no difference in long-term survival between patients who did and did not undergo permanent pacemaker implantation after TAVR. As the use of TAVR expands to include younger and low-risk patients with a long life expectancy, it will become increasingly important to understand the impact of permanent pacemaker implantation after TAVR.

Sex and permanent pacemaker implantation after surgical aortic valve replacement

BACKGROUND

We performed a nationwide population-based cohort study to investigate sex differences in rate of permanent pacemaker implantation after surgical aortic valve replacement (AVR).

METHODS

This study included all adult patients who underwent primary AVR in Sweden between 2005 and 2018. Study data were obtained from the SWEDEHEART register and other Swedish national health-data registers. The rate of permanent pacemaker implantation within 30 days of surgery was compared between men and women. We estimated propensity scores that was used for inverse probability of treatment weighting to account for sex differences in patient characteristics.

RESULTS

A total of 18131 patients were included, 11657(64%) men and 6474(36%) women. The rate of permanent pacemaker implantation did not differ between women and men (3.8% (95% CI, 3.2%-4.3%) vs. 3.7% (95%CI, 3.3%-4.1%);p=0.831). In patients <60 years of age, the rate of permanent pacemaker implantation was significantly higher in women (6.2% (95%CI, 4.3%-8.0%) vs. 3.6% (95%CI, 2.8%-4.4%);p=0.006). The odds of pacemaker implantation in patients <60 years of age was significantly higher in women (odds ratio, 1.76; 95%CI, 1.17-2.63;p=0.006). In patients aged 60-79 years and ≥80 years, the rate of pacemaker implantation did not differ between men and women.

CONCLUSIONS

The rate of permanent pacemaker implantation after surgical AVR in patients <60 years of age was higher in women than men. The susceptibility to conduction disturbances requiring permanent pacemaker implantation in women below 60 years warrants further investigation and should be recognized as transcatheter aortic valve replacement expands into younger patients.

Survival after aortic root replacement with a stentless xenograft is determined by patient characteristics

OBJECTIVES

Our objective was to examine intermediate-term survival and reinterventions in unselected patients, stratified according to indication, who received a Freestyle (Medtronic Inc, Minneapolis, Minn) bioprosthesis as a full aortic root replacement.

METHODS

Data from medical records were retrospectively collected for patients who had aortic root replacement using Freestyle bioprostheses between 1999 and 2018 at 6 North-Atlantic centers. Survival status was extracted from national registries and results stratified according to indication for surgery.

RESULTS

We included 1030 implantations in 1008 patients with elective indications for surgery: aneurysm (39.8%), small root (8.3%), and other (13.8%), and urgent/emergent indications: endocarditis (26.7%) and Stanford type A aortic dissection (11.4%). Across indications, 46.3% were nonelective cases and 34.0% were reoperations. Median age was 66.0 (interquartile range, 58.0-71.8) years and median follow-up was 5.0 (interquartile range, 2.6-7.9) years. Thirty-day mortality varied from 2.9% to 27.4% depending on indication. Intermediate survival for 90-day survivors with elective indications were not different from the general population standardized for age and sex (P = .95, .83, and .16 for aneurysms, small roots, and other, respectively). In contrast, patients with endocarditis and type A dissection had excess mortality (P < .001). Freedom from valve reinterventions was 95.0% and 94.4% at 5 and 8 years, respectively. In all, 52 patients (5.2%) underwent reinterventions, most because of endocarditis.

CONCLUSIONS

At intermediate term follow-up this retrospective study provides further support for the use of the Freestyle bioprosthesis in the real-world setting of diverse, complex, and often high-risk aortic root replacement and suggests that outcome is determined by patient and disease, rather than by prosthesis, characteristics.

Long-term Outcomes Associated With Permanent Pacemaker Implantation After Surgical Aortic Valve Replacement

IMPORTANCE

Prior studies investigating the long-term clinical outcomes of patients who have undergone permanent pacemaker implantation after aortic valve replacement reported conflicting results.

OBJECTIVE

To investigate long-term outcomes after primary surgical aortic valve replacement among patients who underwent postoperative permanent pacemaker implantation.

DESIGN, SETTING, AND PARTICIPANTS

This cohort study included all patients who underwent surgical aortic valve replacement in Sweden from 1997 to 2018. All patients who underwent primary surgical aortic valve replacement in Sweden and survived the first 30 days after surgical treatment were included. Patients who underwent preoperative permanent pacemaker implantation, concomitant surgical treatment for another valve, or emergency surgical treatment were excluded. Patients who underwent concomitant coronary artery bypass grafting or surgical treatment of the ascending aorta were included. Follow-up data were complete for all patients. Data were analyzed from October through December 2020.

EXPOSURES

Patients underwent implantation of a permanent pacemaker or implantable cardioverter defibrillator within 30 days after aortic valve replacement.

MAIN OUTCOMES AND MEASURES

The primary outcome was all-cause mortality.

RESULTS

Among 24 983 patients who underwent surgical aortic valve replacement, 849 patients (3.4%) underwent permanent pacemaker implantation within 30 days after surgical treatment and 24 134 patients (96.6%) did not receive pacemakers in that time. The mean (SD) age of the total study population was 69.7 (10.8) years, and 9209 patients were women (36.9%). The mean (SD) and maximum follow-up periods were 7.3 (5.0) years and 22.0 years, respectively. At 10 years and 20 years after surgical treatment, the Kaplan-Meier estimated survival rates were 52.8% and 18.0% in the pacemaker group, respectively, and 57.5% and 19.6% in the nonpacemaker group, respectively. All-cause mortality was statistically significantly increased in the pacemaker group compared with the nonpacemaker group (hazard ratio [HR], 1.14; 95% CI, 1.01-1.29; P = .03), and so was risk of heart failure hospitalization (HR, 1.58; 95% CI, 1.31-1.89; P < .001). No statistically significant increase was found in the risk of endocarditis in the pacemaker group.

CONCLUSIONS AND RELEVANCE

This study found that there were increased risks of all-cause mortality and heart failure hospitalization among patients who underwent permanent pacemaker implantation after surgical aortic valve replacement, suggesting that these risks are important considerations, especially in an era when transcatheter aortic valve replacement is used in younger patients at lower risk of adverse surgical outcomes. These findings further suggest that future research should investigate how to avoid permanent pacemaker dependency after surgical and transcatheter aortic valve replacement.

Relative survival after aortic valve surgery in patients with bicuspid aortic valves

OBJECTIVES

The objective of this cohort study was to analyse long-term relative survival in patients with bicuspid aortic valve (BAV) who underwent aortic valve surgery.

METHODS

We studied 865 patients with BAVs who participated in three prospective cohort studies of elective, open-heart, aortic valve surgery at the Karolinska University Hospital, Stockholm, Sweden, between 2007 and 2020. The expected survival for the age, sex and calendar year-matched general Swedish population was obtained from the Human Mortality Database. The Ederer II method was used to calculate relative survival, which was used as an estimate of cause-specific survival.

RESULTS

No differences were found in the observed versus expected survival at 1, 5, 10 or 12 years: 99%, 94%, 83% and 76% vs 99%, 93%, 84% and 80%, respectively. The relative survival at 1, 5, 10 and 12 years was 100% (95% CI 99% to 100%), 101% (95% CI 99% to 103%), 99% (95% CI 95% to 103%) and 95% (95% CI 87% to 102%), respectively. The relative survival at the end of follow-up tended to be lower for women than men (86% vs 95%). The mean follow-up was 6.3 years (maximum 13.3 years).

CONCLUSIONS

The survival of patients with BAV following aortic valve surgery was excellent and similar to that of the general population. Our results suggest that the timing of surgery according to current guidelines is correct and provide robust long-term survival rates, as well as important information about the natural history of BAV in patients following aortic valve surgery.

Surgery for Endocarditis in Intravenous Drug Users

BACKGROUND

Few studies have analyzed outcomes after surgery for endocarditis in intravenous drug users (IVDUs). The aim of this study was to compare survival after surgery for endocarditis in IVDUs versus non-IVDUs. Secondary outcomes were the rates of reoperation, reinfection, and relapse to drug use.

METHODS

This population-based, observational cohort study included all patients who had undergone surgery for endocarditis at Karolinska University Hospital between 2002 and 2019. Patient data were collected from the institutional surgical database and medical charts. We used multivariable Cox regression to analyze associations between intravenous drug use and long-term survival.

RESULTS

Of the 510 study patients, 55 were IVDUs (11%) and 455 were not (89%). During a mean follow-up of 5.3 years (maximum, 17.1 years), 30 IVDUs (55%) and 133 non-IVDUs (29%) died. The 30-day mortality was 10.9% and 8.5%, respectively, for IVDUs and non-IVDUs (P = .53). Survival in IVDUs versus non-IVDUs at 1, 5, and 8 years was 76% versus 86%, 49% versus 76%, and 35% versus 68%, respectively (adjusted hazard ratio = 4.12; 95% confidence interval, 2.54-6.68; P < .001). The risk for reoperation was higher in IVDUs (adjusted hazard ratio = 3.47; 95% confidence interval, 1.74-6.89; P < .001). Forty-two IVDUs died or were reinfected (76%) and 49 died or returned to drug use (89%).

CONCLUSIONS

After surgery for endocarditis, IVDUs had substantially higher mortality and reoperation rates than did non-IVDUs. However, postoperative survival was comparable between groups, indicating that IVDUs manage surgery well. Prevention of relapse to drug use is of utmost importance in these patients.

Life expectancy after pulmonary endarterectomy for chronic thromboembolic pulmonary hypertension: a Swedish single-center study

Pulmonary endarterectomy is the guideline recommended treatment for chronic thromboembolic pulmonary hypertension, in addition to life-long anticoagulation therapy. The aim was to analyze long-term relative survival after pulmonary endarterectomy for chronic thromboembolic pulmonary hypertension. We included all patients who underwent pulmonary endarterectomy for chronic thromboembolic pulmonary hypertension at Karolinska University Hospital between 1997 and 2018 (n = 100). We obtained baseline characteristics and vital status from patient charts and national health-data registers. The expected survival from the general Swedish population matched by age, sex, and year of surgery was obtained from the Human Mortality Database. The relative survival was used as an estimate of cause-specific mortality. The mean age of the patients was 62 years and 39% were women. Most patients were severely symptomatic (95% in New York Heart Association functional class III-IV), and mean preoperative systolic/diastolic (mean) pulmonary artery pressure was 78/27 (45) mmHg. The mean and maximum follow-up time was 7.2 and 22.1 years, respectively. Early (30-day) mortality was 7%. The 15-year observed, expected, and relative survival was 55% (95% confidence interval, 40%-68%), 71%, and 77% (95% confidence interval, 56%-95%), respectively. The 15-year relative survival conditional on 30-day survival was 83% (95% confidence interval, 60%-100%). Although the life expectancy following pulmonary endarterectomy was shorter compared to the general population, the difference was small in those who survived the operation and the early postoperative period. Patients with chronic thromboembolic pulmonary hypertension who are surgical candidates should undergo pulmonary endarterectomy to improve prognosis.

ABO blood type and risk of porcine bioprosthetic aortic valve degeneration: SWEDEHEART observational cohort study

OBJECTIVE

Blood type A antigen on porcine aortic bioprostheses might initiate an immune reaction leading to an increased frequency of structural valve deterioration in patients with blood type B or O. The aim was to analyse the association between ABO blood type and porcine bioprosthetic aortic valve degeneration.

DESIGN

Observational nationwide cohort study.

SETTING

Swedish population-based study.

PARTICIPANTS

Adult patients (n=3417) who underwent surgical aortic valve replacement and received porcine bioprosthetic aortic valves between 1995 and 2012 from the Swedish Web system for Enhancement and Development of Evidence-based care in Heart disease Evaluated According to Recommended Therapies register. The study database was enriched with information from other national registers.

EXPOSURE

The patients were categorised into type A/AB and type B/O blood groups.

PRIMARY AND SECONDARY OUTCOME MEASURES

Primary outcome measure was aortic valve reoperation, and secondary outcomes were heart failure and all-cause mortality. We report risk estimates that account for the competing risk of death.

RESULTS

In total, 3417 patients were identified: 1724 (50.5%) with blood type A/AB and 1693 (49.5%) with blood type B/O. Both groups had similar baseline characteristics. The cumulative incidence of aortic valve reoperation was 3.4% (95% CI 2.5% to 4.4%) and 3.6% (95% CI 2.6% to 4.6%) in the type B/O and the A/AB group, respectively, at 15 years of follow-up (absolute risk difference: -0.2% (95% CI -1.5% to 1.2%)). There was no significantly increased risk for aortic valve reoperation in patients with blood type B/O compared with type A/AB (HR 0.95, 95% CI 0.62 to 1.45). There was no significant difference in absolute or relative risk of heart failure or death between the groups.

CONCLUSIONS

We found no significant association between patient blood type and clinical manifestations of structural valve deterioration following porcine aortic valve replacement. Our findings suggest that it is safe to use porcine bioprosthetic valves without consideration of ABO blood type in the recipient.

TRIAL REGISTRATION NUMBER

NCT02276950.

A Type 1 Diabetes Genetic Risk Score Predicts Progression of Islet Autoimmunity and Development of Type 1 Diabetes in Individuals at Risk

OBJECTIVE

We tested the ability of a type 1 diabetes (T1D) genetic risk score (GRS) to predict progression of islet autoimmunity and T1D in at-risk individuals.

RESEARCH DESIGN AND METHODS

We studied the 1,244 TrialNet Pathway to Prevention study participants (T1D patients' relatives without diabetes and with one or more positive autoantibodies) who were genotyped with Illumina ImmunoChip (median [range] age at initial autoantibody determination 11.1 years [1.2-51.8], 48% male, 80.5% non-Hispanic white, median follow-up 5.4 years). Of 291 participants with a single positive autoantibody at screening, 157 converted to multiple autoantibody positivity and 55 developed diabetes. Of 953 participants with multiple positive autoantibodies at screening, 419 developed diabetes. We calculated the T1D GRS from 30 T1D-associated single nucleotide polymorphisms. We used multivariable Cox regression models, time-dependent receiver operating characteristic curves, and area under the curve (AUC) measures to evaluate prognostic utility of T1D GRS, age, sex, Diabetes Prevention Trial-Type 1 (DPT-1) Risk Score, positive autoantibody number or type, HLA DR3/DR4-DQ8 status, and race/ethnicity. We used recursive partitioning analyses to identify cut points in continuous variables.

RESULTS

Higher T1D GRS significantly increased the rate of progression to T1D adjusting for DPT-1 Risk Score, age, number of positive autoantibodies, sex, and ethnicity (hazard ratio [HR] 1.29 for a 0.05 increase, 95% CI 1.06-1.6; P = 0.011). Progression to T1D was best predicted by a combined model with GRS, number of positive autoantibodies, DPT-1 Risk Score, and age (7-year time-integrated AUC = 0.79, 5-year AUC = 0.73). Higher GRS was significantly associated with increased progression rate from single to multiple positive autoantibodies after adjusting for age, autoantibody type, ethnicity, and sex (HR 2.27 for GRS >0.295, 95% CI 1.47-3.51; P = 0.0002).

CONCLUSIONS

The T1D GRS independently predicts progression to T1D and improves prediction along T1D stages in autoantibody-positive relatives.

Survival after Aortic Valve Replacement with Bovine or Porcine Valve Prostheses: A Systematic Review and Meta-Analysis

BACKGROUND

 Bovine and porcine bioprostheses are commonly used for surgical aortic valve replacement. It is unknown if the long-term survival differs between the two valve types.We performed a systematic review and meta-analysis to compare survival in patients who underwent aortic valve replacement and received a bovine or a porcine prosthesis.

METHODS

 We performed a systematic search of Medline, Embase, Web of Science, and the Cochrane Library. Cohort studies that compared survival between patients who underwent aortic valve replacement and received either a bovine or a porcine bioprosthesis and that reported overall long-term survival with hazard ratio (HR) and 95% confidence interval (CI) were included. Two authors independently reviewed articles considered for inclusion, extracted the information from each study, and performed the quality assessment. We performed a meta-analysis using a random effects model to calculate the pooled HR (95% CI) for all-cause mortality. We did sensitivity analyses to assess the robustness of our findings.

RESULTS

 Seven studies published between 2010 and 2015 were included, and the combined study population was 49,190 patients. Of these, 32,235 (66%) received a bovine, and 16,955 (34%) received a porcine bioprosthesis. There was no significant difference in all-cause mortality between patients who received a bovine compared with a porcine bioprosthesis (pooled HR 1.00, 95% CI: 0.92-1.09). Heterogeneity between studies was moderate (55.8%, p = 0.04).

CONCLUSIONS

 This systematic review and meta-analysis suggest no difference in survival between patients who received a bovine versus a porcine bioprosthesis after aortic valve replacement. Our study provides valuable evidence for the continuing use of both bovine and porcine bioprosthetic valves for surgical aortic valve replacement.

Late Survival After Aortic Valve Replacement in Patients With Moderately Reduced Kidney Function

Background

The influence of moderately reduced kidney function on late survival after surgical aortic valve replacement (AVR) is unknown. We analyzed survival after AVR in patients with moderately reduced kidney function.

Methods and Results

All patients who underwent primary AVR in Sweden 1997–2013 were identified from the Swedish Web system for Enhancement and Development of Evidence‐based care in Heart disease Evaluated According to Recommended Therapies register. Patients were categorized according to estimated glomerular filtration rate (eGFR). Of 13 102 patients, 9836 (75%) had normal kidney function (eGFR >60 mL/min per 1.73 m²) and 3266 (25%) had moderately reduced kidney function (eGFR 30–60 mL/min per 1.73 m²). Mean follow‐up time was 6.2 years. Mortality was higher in patients with moderately reduced kidney function; 5‐, 10‐, and 15‐year survival was 76%, 48%, and 25% versus 89%, 73%, and 55% (adjusted hazard ratio [HR], 1.28; 95% CI, 1.18–1.38; P<0.001). Patients with moderately reduced kidney function had a nonsignificantly higher risk of major bleeding (HR, 1.18; 95% CI, 1.00–1.39; P=0.051) and a lower risk for aortic valve reoperation (HR, 0.54; 95% CI, 0.38–0.79; P=0.001) compared to those with normal kidney function. In patients with moderately reduced kidney function, survival was similar in those who received bioprostheses compared to those who received mechanical valves (HR, 0.85; 95% CI, 0.70–1.03; P=0.094).

Conclusions

Moderately reduced kidney function was strongly associated with increased mortality after AVR. These results have important implications for preoperative risk stratification, and suggest that patients with eGFR 30 to 60 mL/min per 1.73 m² warrant careful observation after AVR.

Clinical Trial Registration

URL: http://www.clinicaltrials.gov. Unique identifier: NCT02276950.

Aortic valve replacement through full sternotomy with a stented bioprosthesis versus minimally invasive sternotomy with a sutureless bioprosthesis

OBJECTIVES

The aim of this study was to analyse early postoperative outcomes and 2-year survival after aortic valve replacement (AVR) through a ministernotomy with a sutureless bioprosthesis implantation compared with a full sternotomy with implantation of a stented bioprosthesis.

METHODS

Patients who underwent primary isolated non-emergent AVR at six European centres were included in the study. Of these, 182 (32%) underwent a ministernotomy with a sutureless bioprosthesis (ministernotomy sutureless group) and 383 (68%) a full sternotomy with a stented bioprosthesis (full sternotomy stented group). Propensity score matching was used to reduce selection bias.

RESULTS

In the overall cohort, 30-day mortality was 1.6 and 2.1%, and 2-year survival was 92 and 92% in the ministernotomy sutureless group and in the full sternotomy stented group, respectively. Propensity score matching resulted in 171 pairs with similar characteristics and operative risk. Aortic cross-clamp (40 vs 65 min, P < 0.001) and cardiopulmonary bypass time (69 vs 87 min, P < 0.001) were shorter in the ministernotomy sutureless group. Patients undergoing ministernotomy received less packed red blood cells but the risk for postoperative permanent pacemaker implantation was higher. There were no differences regarding 30-day mortality or 2-year survival between the two groups.

CONCLUSIONS

AVR through a ministernotomy with implantation of a sutureless bioprosthesis was associated with shorter aortic cross-clamp and cardiopulmonary bypass time and less transfusion of packed red blood cells, but a higher risk for postoperative permanent pacemaker implantation compared with a full sternotomy with a stented bioprosthesis.

Late haemodynamic performance and survival after aortic valve replacement with the Mosaic bioprosthesis

OBJECTIVES

The objective was to evaluate the long-term haemodynamic performance of the Mosaic aortic bioprosthesis. Secondary objectives were to investigate the long-term survival, the rate of aortic valve reoperations, and the rate of prosthesis-patient mismatch and its effect on long-term survival.

METHODS

We included all patients who underwent aortic valve replacement with a Mosaic bioprosthesis at our institution between 2002 and 2008. Valve haemodynamics were assessed by transthoracic echocardiography as mean and peak pressure gradients. Patient characteristics and outcomes were collected from charts and national registers.

RESULTS

We included 355 patients and echocardiographic evaluation was performed at early follow-up in 340 patients (96%) and at late follow-up in 161 patients (45%). The mean follow-up time was 7.1 (maximum 11.7) years. The unadjusted survival at 1, 5 and 10 years was 92, 79 and 42%, respectively. At the early postoperative echocardiography, the peak pressure gradient was 39.9 mmHg (SD 14.4) and the mean pressure gradient was 21.1 mmHg (SD 7.7) and, on late echocardiography, the peak pressure gradient was 38.6 mmHg (SD 15.6) and the mean pressure gradient was 22.5 mmHg (SD 10.1). Moderate or severe prosthesis-patient mismatch was found in 250 (70%) and 49 patients (14%), respectively, but was not significantly associated with mortality in multivariable analyses.

CONCLUSIONS

We found that the Mosaic aortic bioprosthesis had acceptable clinical performance at late follow-up. However, a substantial proportion of patients had high transvalvular gradients or moderate or severe prosthesis-patient mismatch, although neither were significantly associated with long-term survival in our population.

Obsessive compulsive disorder in a woman with left basal ganglia infarct: A case report

This report presents a syndrome resembling obsessive convulsive disorder (OCD) secondary to a stroke in the left basal ganglia. The patient's syndrome is virtually identical to those that have been described in bilateral damage of the basal ganglia. However, the stroke described in this case report is located unilaterally in the left basal ganglia. In addition, experience in treating a patient with OCD induced by structural damage of basal ganglia is presented.

Late survival after aortic valve replacement with the perimount versus the mosaic bioprosthesis

BACKGROUND

The objective was to compare late survival after aortic valve replacement (AVR) with a Carpentier-Edwards Perimount (Edwards Lifesciences, Irvine, CA) versus a Mosaic bioprosthesis (Medtronic Inc, Minneapolis, MN). Secondary objectives were to compare early mortality, the rate of reoperation, and the effect of prosthesis-patient mismatch (PPM) on late survival.

METHODS

The design was a population-based cohort study including all patients who underwent AVR with a Perimount or Mosaic bioprosthesis at our institution between 2002 and 2010. Baseline, operative characteristics and clinical outcomes were collected from patient charts and national registers. The primary outcome was all-cause mortality. We analyzed the unadjusted and multivariable adjusted association between valve type and late survival.

RESULTS

In total, 1,219 patients received the Perimount (n=864) or the Mosaic (n=355) bioprosthesis. During a mean follow-up of 4.2 and 6.9 years, there were 193 and 177 deaths in the Perimount and Mosaic groups, respectively. The unadjusted 1-, 5-, and 8-year survival was 93%, 78%, and 63%, respectively, in the Perimount group and 92%, 80%, and 57%, respectively, in the Mosaic group (p=0.971).There was no significant association between valve choice and all-cause mortality in the multivariable analysis (hazard ratio [HR], 0.85; 95% confidence interval [CI], 0.65-1.11). Freedom from aortic valve reoperation was similar between the groups. No significant association was found between severe PPM and late mortality.

CONCLUSIONS

We found no significant difference in late survival after AVR with a Perimount bioprosthesis compared with a Mosaic bioprosthesis. Even though severe PPM was more common in the Mosaic group, it did not affect the late survival or the frequency of reoperation.

Early bioprosthetic mitral valve failure due to fusion of the cusps

Modern extracorporeal membrane oxygenation support has revolutionized the survival outcome of critically ill patients with refractory cardiac failure. Mitral valve replacement in patients treated with extracorporeal membrane oxygenation poses a surgical challenge regarding the choice of appropriate prosthesis. We present two cases of mitral valve bioprosthetic failure within days to weeks after valve replacement. Both patients were supported with extracorporeal membrane oxygenation postoperatively, and the bioprosthetic failure was caused by fusion of the cusps. This mechanism of mitral valve bioprosthetic failure in combination with extracorporeal membrane oxygenation treatment has not previously been described.

Cerebral edema in children with diabetic ketoacidosis

Cerebral edema is the most frequent serious complication of diabetic ketoacidosis (DKA) in children, occurring in 1% to 5% of DKA episodes. The rates of mortality and permanent neurologic morbidity from this complication are high. The pathophysiologic mechanisms underlying DKA-related cerebral edema are unclear. A number of past and more recent studies have investigated biochemical and therapeutic risk factors for the development of cerebral edema. Recent studies have shown that a higher initial serum urea nitrogen concentration and lower initial partial pressure of carbon dioxide are associated with the development of cerebral edema. This and other information suggests that the pathophysiology of DKA-related cerebral edema may involve cerebral ischemia.

Risk factors for cerebral edema in children with diabetic ketoacidosis. The Pediatric Emergency Medicine Collaborative Research Committee of the American Academy of Pediatrics

BACKGROUND

Cerebral edema is an uncommon but devastating complication of diabetic ketoacidosis in children. Risk factors for this complication have not been clearly defined.

METHODS

In this multicenter study, we identified 61 children who had been hospitalized for diabetic ketoacidosis within a 15-year period and in whom cerebral edema had developed. Two additional groups of children with diabetic ketoacidosis but without cerebral edema were also identified: 181 randomly selected children and 174 children matched to those in the cerebral-edema group with respect to age at presentation, onset of diabetes (established vs. newly diagnosed disease), initial serum glucose concentration, and initial venous pH. Using logistic regression we compared the three groups with respect to demographic characteristics and biochemical variables at presentation and compared the matched groups with respect to therapeutic interventions and changes in biochemical values during treatment.

RESULTS

A comparison of the children in the cerebral-edema group with those in the random control group showed that cerebral edema was significantly associated with lower initial partial pressures of arterial carbon dioxide (relative risk of cerebral edema for each decrease of 7.8 mm Hg [representing 1 SD], 3.4; 95 percent confidence interval, 1.9 to 6.3; P<0.001) and higher initial serum urea nitrogen concentrations (relative risk of cerebral edema for each increase of 9 mg per deciliter [3.2 mmol per liter] [representing 1 SD], 1.7; 95 percent confidence interval, 1.2 to 2.5; P=0.003). A comparison of the children with cerebral edema with those in the matched control group also showed that cerebral edema was associated with lower partial pressures of arterial carbon dioxide and higher serum urea nitrogen concentrations. Of the therapeutic variables, only treatment with bicarbonate was associated with cerebral edema, after adjustment for other covariates (relative risk, 4.2; 95 percent confidence interval, 1.5 to 12.1; P=0.008).

CONCLUSIONS

Children with diabetic ketoacidosis who have low partial pressures of arterial carbon dioxide and high serum urea nitrogen concentrations at presentation and who are treated with bicarbonate are at increased risk for cerebral edema.

Home monitoring for infants at high risk for the sudden infant death syndrome

The rate of sudden infant death syndrome (SIDS) In Israel is relatively low (0.5-0.9:1,000). Home cardiorespiratory monitoring (HM) is an accepted practice in infants at high risk for SIDS. We report our experience with 261 infants who were referred to our SIDS prevention program. They included: 52 preterm infants with apneas and bradycardias, 83 SIDS siblings (3 twins), 22 infants of drug-addicted mothers, and 104 infants after an idiopathic apparent life-threatening event (ALTE). HM was performed in 40 of 52 preterms, 38 of 83 SIDS siblings, all 22 infants of addicted mothers and 67 of 104 post-ALTE. All received 24 h/day medical and technical backup as well as emotional support, and were closely followed until 15 months of age. None of the 261 infants died. Five infants experienced six ALTEs that required resuscitative measures; another 28 infants had monitor alarms judged as real by the caregivers. The average duration of HM was 3.2 months (range 1-7). In 8 of 167 cases the parents stopped HM earlier than recommended, and in 34 of 167 cases (20%), parents continued HM beyond the time when discontinuation was recommended by the medical personnel. Among the caregivers, 85% found HM to be reassuring and stated that it helped them to conduct a normal life. We suggest that in our population, HM may have a favorable effect on family life. With close backup and support, most families will benefit from HM and will gain reassurance that will enable them to conduct normal life.

Hermansky-Pudlak syndrome: case report and clinicopathologic review

The Hermansky-Pudlak syndrome is an autosomal recessive disorder consisting of the triad of albinism, a bleeding diathesis, and ceroid deposition within the reticuloendothelial system. In this study of a patient with Hermansky-Pudlak syndrome, we demonstrate the presence of ceroid within dermal macrophages. Electron microscopic studies suggest that melanosomes may be a substrate for the formation of ceroid in the skin. A review of the clinical and pathophysiologic features of this disorder is presented.

AIDS-related angiomatosis

We report multifocal cutaneous and mucosal vascular proliferations with the clinical and histological features of lobular capillary hemangioma and histiocytoid hemangioma in a 32-year-old acquired immunodeficiency syndrome patient. The lesions resolved subsequent to erythromycin therapy.

Cytofluorometry as a method for the differentiation of trypanosomes

The DNA binding guanine specific antibiotic, chromomycin A3, has been evaluated for fluorescence intensity measurements of T. cruzi, T. brucei brucei and T. musculi. Optimal fixation and staining conditions have been determined. The fluorometry was performed with a microscope photometer equipped with electronic systems for short time excitation of 7 milliseconds and operation control. The trypomastigote bloodstream forms of these species have a different chromomycin specific DNA content. The total DNA content of T. cruzi was 2.1-fold higher than for T.b. brucei and 2.3-fold higher than for T. musculi. The nuclear DNA content also was higher in T. cruzi. The nuclear DNA values were recorded to be 1.6-fold greater than in T.b. brucei and 2.0-fold greater than in T. musculi. The amount of the kinetoplast DNA of T. cruzi was shown to be 3.2-fold higher than in T. musculi and 11.7-fold higher than in T.b. brucei. The higher total DNA of T.b. brucei in relation to T. musculi was based on the nuclear values because the content of the kinetoplast DNA of T.b. brucei was 3.7-fold smaller than of T. musculi. The kDNA comprised 25% in T. cruzi, 18% in T. musculi and only 4% in T.b. brucei of the total amount of the chromomycin specific DNA. The chromomycin fluorescence intensities of the DNA of trypanosomes were subjected to a statistical model of discriminant analysis. It was possible to get perfect separation of the three trypanosome species. The hit rate was 100%.

Relationship of CSF shunting and IQ in children with myelomeningocele: a retrospective analysis

This paper reviews 75 infants with myelomeningocele treated either at birth or from an early age at Rainbow Babies and Children's Hospital, for whom complete records and psychometric testing (IQ) are available (including complete summaries from referring hospitals). Three groups are compared: (1) infants without complications who were shunted for hydrocephalus (n = 41); (2) infants with complications who were shunted (n = 16), and (3) infants who were not shunted (n = 18). Complications were defined as ventriculitis (positive CSF cultures with elevated protein, depressed glucose and inflammatory cells), anoxia, poorly controlled hydrocephalus or other CNS anomalies such as porencephaly. The mean IQ of infants who were not shunted was 104, of those shunted without complications it was 91, and of those shunted who had complications it was 70. These IQ differences were significant at p less than 0.01, and were not explained by differences in spinal lesion levels.