Risk assessment in patients with symptomatic and asymptomatic pre-excitation

AIMS

Controversy remains as to whether the exercise stress test (EST) is sufficient for risk evaluation in patients with pre-excitation. This study aims to clarify the usefulness of EST in risk stratification in both asymptomatic and symptomatic patients presenting with pre-excitation.

METHODS AND RESULTS

This prospective study includes consecutive asymptomatic and symptomatic patients with pre-excitation referred for risk assessment. All participants performed an incremental EST (bicycle) prior to an electrophysiology study (EPS). Primary data from the EST included loss of pre-excitation during exercise, and primary data from the EPS included the measurement of accessory pathway effective refractory period (APERP), shortest pre-excited RR interval (SPERRI), and inducible arrhythmia with the use of a beta-adrenergic receptor agonist if deemed necessary. One hundred and sixty-four patients (59 asymptomatic, 105 symptomatic) completed an EST and EPS. Forty-five patients (27%) demonstrated low-risk findings on EST, of which 19 were asymptomatic and 26 were symptomatic. Six patients with low-risk EST findings had SPERRI/APERP ≤ 250 ms at EPS, and two of them were asymptomatic. The sensitivity, specificity, positive predictive value, negative predictive value (NPV), and accuracy of low-risk EST for excluding patients with SPERRI/APERP ≤ 250 ms were 40, 91, 87, 51, and 60%, respectively. The number of patients with inducible arrhythmia at EPS was similar in the asymptomatic (36, 69%) and symptomatic (73, 61%) groups.

CONCLUSION

Sudden loss of pre-excitation during EST has a low NPV in excluding high-risk APs. The EPS with the use of isoproterenol should be considered to accurately assess the risk of patients with pre-excitation regardless of symptoms (ClinicalTrials.gov Identifier: NCT03301935).

Association between catheter ablation of atrial fibrillation and mortality or stroke

OBJECTIVE

Catheter ablation of atrial fibrillation effectively reduces symptomatic burden. However, its long-term effect on mortality and stroke is unclear. We investigated if patients with atrial fibrillation who undergo catheter ablation have lower risk for all-cause mortality or stroke than patients who are managed medically.

METHODS

We retrospectively included 5628 consecutive patients who underwent first-time catheter ablation for atrial fibrillation between 2008 and 2018 at three major Swedish electrophysiology units. Control individuals with an atrial fibrillation diagnosis but without previous stroke were selected from the Swedish National Patient Register, resulting in a control group of 48 676 patients. Propensity score matching was performed to produce two cohorts of equal size (n=3955) with similar baseline characteristics. The primary endpoint was a composite of all-cause mortality or stroke.

RESULTS

Patients who underwent catheter ablation were healthier (mean CHA2DS2-VASc score 1.4±1.4 vs 1.6±1.5, p<0.001), had a higher median income (288 vs 212 1000 Swedish krona [KSEK]/year, p<0.001) and had more frequently received university education (45.1% vs 28.9%, p<0.001). Mean follow-up was 4.5±2.8 years. After propensity score matching, catheter ablation was associated with lower risk for the combined primary endpoint (HR 0.58, 95% CI 0.48 to 0.69). The result was mainly driven by a decrease in all-cause mortality (HR 0.51, 95% CI 0.41 to 0.63), with stroke reduction showing a trend in favour of catheter ablation (HR 0.75, 95% CI 0.53 to 1.07).

CONCLUSIONS

Catheter ablation of atrial fibrillation was associated with a reduction in the primary endpoint of all-cause mortality or stroke. This result was driven by a marked reduction in all-cause mortality.

Electrical cardioversion for early recurrences post pulmonary vein isolation

BACKGROUND

To study the association between timing and success of electrical cardioversion (ECV) for the treatment of early recurrences (ERs) of atrial fibrillation post pulmonary vein isolation (PVI) on long-term rhythm outcome.

METHODS

Data of 133 patients ablated for paroxysmal or persistent atrial fibrillation receiving ECV for ERs, i.e., atrial tachyarrhythmia recurrences within 90 days post ablation were analyzed. During 1-year follow-up, patients were screened for late recurrences (LRs), i.e., recurrences after the blanking period.

RESULTS

In 114 patients (85.7%), ECV was successful compared to 19 patients (14.3%) with failed ECV. A higher body mass index (odds ratio (OR) 1.19 (95% CI 1.02-1.39), p = 0.029), a lower left ventricular ejection fraction (OR 1.07 (95% CI 0.99-1.15), p = 0.079), and performance of ECV > 7 days from ER onset (OR 2.99 (95% CI 1.01-8.87), p = 0.048) remained independently associated with ECV failure. During 1-year follow-up, the rate of LR was significantly higher among patients with failed ECV as compared to patients with successful ECV (hazard ratio (HR) 3.00 (95% CI, 1.79-5.03), p < 0.001). Patients with ECV performed > 7 days from ER onset had a significantly higher risk of developing LR as compared to patients with ECV performed within ≤ 7 days from ER onset (HR 1.73 (95% CI 1.15-2.62), p = 0.009). Performance of ECV > 7 days from ER onset (HR 1.76 (95% CI 1.16-2.67), p = 0.008) and failed ECV (HR 3.32 (95% CI 1.96-5.64), p < 0.001) remained independently associated with LR.

CONCLUSIONS

A failed ECV and performance of ECV > 7 days from ER onset were independently associated with LR.

P-793 The effect of Nuclear Receptor Subfamily 5 Group A Member 1 (NR5A1) in human ovarian somatic cell development

Study question

Can an inducible NR5A1 (encoding Steroidogenic Factor 1) cell line be used to study the functional role of NR5A1 in human female gonadal differentiation?

Summary answer

Conditional induction of NR5A1 in a human pluripotent stem cell (hPSC)-based model of gonadal differentiation allows us to study its effect on the differentiating cells.

What is known already

According to animal studies, NR5A1 is a critical factor in gonadal development. Previous research in our lab showed that CRISPR/Cas9 induced upregulation of NR5A1 during gonadal differentiation in male (XY) hPSCs increases expression of early Sertoli cell markers such as Inhibin A and Anti-Müllerian hormone (AMH) and thus pushes the cells into a more mature gonadal cell type. However, the role of NR5A1 in female gonadal differentiation has yet to be determined.

Study design, size, duration

The female (XX) human embryonic stem cell (hESC) line, H9, was edited using CRISPR/Cas9 to conditionally induce NR5A1. These cells were subjected to a 10/20-day gonadal differentiation protocol where NR5A1 was induced through addition of Doxycycline (DOX) and Trimethoprim (TMP) from day 4 until day 10/20. Starting from day 4 technical duplicates/triplicates from every second day were subjected to qRT-PCR. Technical triplicates from day 4, 6, 8 and 10 were subjected to bulk RNA-sequencing.

Participants/materials, setting, methods

The cell line that was used in this project is a female hESC line, H9 (WiCell). A previously established protocol for gonadal differentiation (Sepponen et al., 2017) was followed wherein different cell culture media and matrices were supplemented with small molecules, inhibitors and growth factors. The CRISPR/Cas9 genome-editing system was used to generate the NR5A1 inducible cell line. Cell characterisation was performed using qRT-PCR and bulk RNA sequencing (NovaSeq S4) methods.

Main results and the role of chance

qRT-PCR results showed that without NR5A1 induction there was almost no expression of this gene, but its expression increased drastically upon addition of DOX and TMP to the culture media. NR5A1 induction seemed to upregulate FOXL2 and WNT4, which are crucial genes for female gonadal differentiation, although the increase was not statistically significant. AMH showed a significant increase on day 8 of differentiation after NR5A1 induction. We also saw an increase in the expression of steroidogenic genes such as STAR, CYP11A1, CYP17A1 and CYP19A1 after NR5A1 induction. Subjecting the cells to NR5A1 induction for an additional 10 days resulted in the upregulation of bipotential gonadal markers GATA4, WT1 and EMX2 after NR5A1 induction. Similarly, the female gonadal markers RSPO1 and WNT4 were upregulated over time and WNT4 expression further increased upon NR5A1 induction.

NovaSeq S4 data showed that on day 8, after induction of NR5A1, genes related to reproductive system development and female pregnancy were upregulated. These included DHH, NR5A1, CYP19A1, AR, INHA and NR0B1. On day 10 genes related to reproductive system development such as FOXL2, NR5A1, INHA, LHCGR, and NR0B1 were also upregulated after NR5A1 induction.

Limitations, reasons for caution

The effect of NR5A1 induction on expression levels of bipotential gonadal markers GATA4, LHX9, WT1, EMX2 and female gonadal markers FOXL2, RSPO1, WNT4 was small in comparison to differentiation without additional NR5A1 induction. Moreover, we lack a protocol to generate bipotential gonadal cells expressing NR5A1 without inducing NR5A1 through CRISPR/Cas9.

Wider implications of the findings

Taken together the results will provide valuable insight and novel information on the function of NR5A1 in early female gonadal development and more in general on human ovarian development and sex determination. This knowledge will increase our understanding of pathological gonadal development, which often underlies disorders of sex development.

Trial registration number

Not applicable

Accessory pathway properties are similar in symptomatic and asymptomatic preexcitation

PURPOSE

Patients with WPW syndrome have an increased mortality rate compared to the general population. Although asymptomatic preexcitation has previously been considered benign, recent studies have found that also asymptomatic patients have clinical and electrophysiological factors associated with increased risk of sudden cardiac death. This study compares the baseline electrophysiological characteristics of accessory pathways in symptomatic and asymptomatic patients with preexcitation. We hypothesized that a significant proportion of asymptomatic patients has inducible orthodromic tachycardia during programmed electrical stimulation.

METHODS

This retrospective study includes 1853 patients with preexcitation who underwent invasive electrophysiological testing in two Swedish University Hospitals between 1991 and 2018. The mean age was 36 ± 17 years with a range of 3-89 years. Thirty-nine percent was women. A total of 269 patients (15%) were children younger than 18 years. Electrophysiological data included effective refractory period of the accessory pathway (APERP, in 1069 patients), tachycardia cycle length, inducibility and type of tachycardia, and AP localization.

RESULTS

A total of 1703 (93%) patients reported symptoms suggesting tachyarrhythmias before the study and 128 (7%) were asymptomatic. The proportion of potentially dangerous pathways with short APERP (≤ 250 ms) were similar in symptomatic and asymptomatic patients (187/949, 20% vs. 25/108, 23%) (P = 0.40) as was the mean APERP (303 ± 68 ms vs. 307 ± 75) (P = 0.61). The proportion of patients who had inducible arrhythmia was larger in the symptomatic group (64% vs. 31%) (P < 0.001).

CONCLUSION

The results of this study strengthen the present guideline recommendation (IIA) to consider invasive risk assessment in patients with asymptomatic preexcitation.

Low incidence of major complications after the first six hours post-atrial fibrillation ablation – same-day discharge safe and feasible in most patients

Background/Introduction

Catheter ablation of atrial fibrillation (AF) is associated with a complication risk. It is common practice to monitor patients overnight post-procedurally which is resource craving.

Purpose

To evaluate the incidence of procedural complications related to catheter ablation of AF to assess the potential feasibility and safety of same day discharge in a large cohort.

Methods

We performed an analysis of prospectively collected data of complications of all patients staying overnight after undergoing AF ablation between 2001 and 2020 at a tertiary centre. By studying medical records, we analysed complications occurring intraprocedurally until six hours post-ablation, and between six hours post-ablation until discharge the day after ablation procedure (up to 24 hours post-procedure).

Results

In 5414 AF ablations we identified a total of 108 (2.0%) major complications occurring intraprocedural or until discharge the day after procedure. Most major complications occurred early and were detected intraprocedurally or within six hours after completed procedure (n=96, 1.8%). Twelve (0.2%) major complications occurred between six hours post-ablation and until discharge the day after procedure. The most common of these were congestive heart failure (n=6) and transient ischemic attack (TIA, n=4). In addition, there were 61 (1.1%) minor complications which occurred in this time span. Factors independently associated with major complications intraprocedurally or within 24 hours were age (p=0.046), body mass index (BMI) ≥30 kg/m2 (p=0.009), significant valvular disease (p=0.001), cardiomyopathy (p&lt;0.001), prior stroke or TIA (p=0.014), first time procedure vs. repeat procedure (p=0.013), cryoablation vs. radiofrequency (p&lt;0.001) and procedure duration (p&lt;0.001).

Conclusion

Very few complications occurred between six hours and until discharge after ablation of atrial fibrillation. Therefore, same-day discharge may be a safe option for a large proportion of patients.

Funding Acknowledgement

Type of funding sources: Public grant(s) – National budget only. Main funding source(s): Region Stockholm funding

Cryoablation of atypical atrioventricular nodal reentry tachycardia

AIM

Data on ablation for atypical recurrent atrioventricular nodal reentry tachycardia (AVNRT) and long-term follow-up are generally sparse. Furthermore, the rate of recurrence and safety of cryoablation for atypical AVNRT has not been established. We compared patients cryoablated for atypical AVNRT and typical AVNRT during long-term follow-up.

METHODS

All patients (n = 2612) who underwent catheter ablation for AVNRT at the Karolinska University Hospital between January 2009 and August 2019 were analyzed. A total of 91 patients undergoing first-time cryoablation for atypical AVNRT were included. A control group with first-time cryoablation for typical AVNRT was matched in a 1:1 ratio. Patients were followed-up for recurrences for a median of 5.0 years (interquartile range: 3.1-7.5 years).

RESULTS

After 5 years, AVNRT recurrence occurred in 10 patients (11.0%) in the atypical AVNRT group and in 8 patients (8.8%) in the typical AVNRT group (hazard ratio: 1.31 [95% confidence interval: 0.52-3.32]; p = 0.568). The duration of the index procedure was significantly longer for atypical compared to typical AVNRT ablation (132.1 ± 49.2 min vs. 110.1 ± 38.8 min; p = 0.001). Transient AV blocks occurred in a similar fashion in the atypical compared to typical group (11 [12.1%] vs. 4 [4.9%]; p = 0.103). However, no ablation induced persistent AV block developed in either group.

CONCLUSION

Cryoablation for atypical AVNRT showed similar rate of recurrences and safety compared to typical AVNRT during long-term follow-up.

Low incidence of major complications after the first six hours post atrial fibrillation ablation: Is same-day discharge safe and feasible in most patients?

AIMS

This study evaluates the incidence of procedural complications related to catheter ablation of atrial fibrillation (AF) to assess the potential feasibility and safety of same-day discharge in a large cohort.

METHODS

We performed an analysis of prospectively collected data of complications of all patients staying overnight after undergoing AF ablation between 2001 and 2020 at a tertiary center. Using medical records, we analyzed complications occurring intraprocedurally until 6 h postablation and between 6 h postablation and discharge the day after the ablation procedure.

RESULTS

In 5414 AF ablations, we identified a total of 108 (2.0%) major complications occurring intraprocedural or before discharge. Most major complications occurred intraprocedurally or within 6 h after the procedure (n = 96, 1.8%). Twelve (0.2%) major complications occurred between 6 h Postablation and discharge. The most common of these major complications were congestive heart failure (n = 6) and transient ischemic attack (TIA, n = 4). During this time span, 61 (1.1%) minor complications occurred. Factors independently associated with major complications intraprocedurally and until discharge were body mass index (BMI) ≥ 30 kg/m² (p = .009), significant valvular disease (p = .001), cardiomyopathy (p < .001), prior stroke or TIA (p = .014), first-time procedure versus repeat procedure (p = .013), cryoablation versus radiofrequency (p < .001), and procedure duration (p < .001).

CONCLUSION

After AF ablation, very few complications occurred between 6 h postprocedure and discharge the next day. Therefore, same-day discharge is a safe option for a majority of patients.

O-163 Hyperandrogenaemia in early adulthood is an independent risk factor for abnormal glucose metabolism in later life

Study question

What is the role of androgen excess as a contributing factor to insulin resistance and abnormal glucose metabolism (AGM) in women?

Summary answer

There was a positive association between early adulthood hyperandrogenaemia with AGM. Serum SHBG levels could help identifying women at risk for disordered glucose metabolism.

What is known already

It is commonly recognised that insulin resistance induces compensatory hyperinsulinaemia which promotes ovarian androgen secretion. Studies in rodents have also suggested that testosterone causes prolonged activation of androgen receptor in pancreatic islet β-cells, inducing insulin hypersecretion and eventually secondary β-cell failure, thus predisposing to type 2 diabetes (T2D). However, the exact physiology behind the association between androgens, insulin resistance and T2D in women is not well understood. Many previously published studies are limited by cross-sectional study design, unrepresentative clinic populations, as well as variying steroid hormone measurement methods and definitions of androgen excess.

Study design, size, duration

A prospective longitudinal population-based cohort (n = 5,889) to investigate whether serum levels of testosterone (T, measured using LC-MS/MS) and free androgen index (FAI) at ages 31 and 46 associated with AGM at age 46 years. After exclusion of pregnant women, users of hormonal intrauterine device, contraceptive pills, hormone therapy, minipills and statins, there were 4,421 women at age 31 and 4,457 women at age 46. At age 46 a two-hour OGTT was performed in 2,780 women.

Participants/materials, setting, methods

Serum fasting glucose and insulin, insulin resistance (HOMA–IR) and pancreatic β-cell function (HOMA–B) assessments were performed at ages 31 and 46. Elevated T levels (age 31: &gt;2.3nmol/l; age 46: &gt;1.7nmol/l) were defined according to the 97.5% percentile. T2D diagnoses were gathered from postal questionnaire at age 46, and verified and completed from the hospital discharge and national medication reimbursement registers. Impaired fasting glucose, impaired glucose tolerance or T2D were categorised as AGM.

Main results and the role of chance

At age 31, hyperandrogenic (HA) women displayed increased insulin resistance estimated by HOMA-IR (1.35±0.96 vs. 1.03±0.44, P = 0.05), increased insulin secretion estimated by HOMA-B (115.05±34.67 vs. 99.25±25.47, P = 0.006), and higher fasting insulin level (10.48±7.54 mU/l vs. 7.93±3.42 mU/l, P = 0.034) compared with normoandrogenic (NA) women, after BMI adjustment. At age 46, HA women had comparable HOMA-B levels (98.04±60.03 vs. 96.27±65.89, P = 0.93) but their fasting glucose (5.57±1.06 mmol/l vs. 5.37±0.77 mmol/, P = 0.07) and glycated haemoglobin levels (37.47±7.83 mmol/mol vs. 36.18±4.99 mmol/mol, P = 0.07) tended to be higher.

Women in the highest T quartile (Q4

odds ratio [OR]=1.77, 95%CI: [1.14–2.76]) and in the two highest FAI quartiles at age 31 (Q4: OR = 3.61 [2.16–6.03] and Q3: OR = 2.11 [1.24–3.59]) had increased risk for AGM at age 46, independently of BMI, when compared with women in the lowest quartile. Similarly, women in the two highest FAI quartiles at age 46 had increased risk for AGM (Q4: OR = 2.91 [1.82–4.64]) when compared with women in the lowest quartile, after BMI adjustment. The three highest sex hormone-binding globulin (SHBG) quartiles inversely associated with AGM, both at ages 31 and 46, independently of BMI (at age 31: Q4: OR = 0.38 [0.24–0.62], at age 46: Q4: OR = 0.27 [0.17–0.44]).

Limitations, reasons for caution

We used only serum T as a marker of HA, even though other androgens, such as androstenedione and adrenal androgens have a place in the evaluation of androgenicity in women. Further studies of other large populations are needed to confirm our results.

Wider implications of the findings

This is the first longitudinal, general population based study to confirm a positive association between early adulthood hyperandrogenaemia with AGM in middle adulthood independently of confounding factors. Our results further suggest that SHBG levels could help to identify women at risk for AGM.

Trial registration number

NA

Cryoablation as standard treatment of atrial flutter: a prospective, 2-center study (CASTAF)

BACKGROUND

Cryoablation (CRYO) of cavotricuspid isthmus (CTI)-dependent atrial flutter (AFL) has been shown to be non-inferior to radiofrequency ablation (RF) in terms of ablation success and is associated with less pain. However, procedural time has been significantly longer with CRYO compared to RF. A possible explanation for this could be that operators had less experience with CRYO than with RF. The purpose of this study was to test the hypothesis that in the hands of experienced operators, cryoablation of CTI-dependent AFL is effective with procedure-time similar to what is reported for RF.

METHODS

This prospective 2-center study included 184 patients with CTI-dependent AFL - median age 66 years (range 28-83), 159 men (86%). Cryoablation was performed using a 9 F, 8 mm tip catheter (Freezor MAX, Medtronic, Inc, MN, USA). Ablation endpoint was bidirectional CTI-block. Pain was evaluated with a visual analogue scale (VAS 0-10). All operators had experience of at least 25 previous CTI-ablations with CRYO.

RESULTS

The acute success rate was 89%. Procedural time including an observation period of 30 min, was 115 ± 36 min which is similar to procedural times for RF in previous studies. Fluoroscopy time was 11 ± 9 min. Cryoablation was perceived as almost pain- free by the patients, VAS (mean) 1.8 ± 1.2. Success rate at 12-month follow-up (FU) was 88% in patients with primary success. No major adverse events occurred.

CONCLUSIONS

Cryoablation of CTI-dependent AFL is effective, with a low level of procedure-related pain. In experienced hands, the procedure time in this prospective non-randomised trial seems to be in the level of reported procedure times for RF. The long-term relapse rate appears to be higher than for RF.

Sinus heart rate post pulmonary vein ablation and long-term risk of recurrences

PURPOSE

Cather ablation is known to influence the autonomic nervous system. This study sought to investigate the association of sinus heart rate pre-/post-ablation and recurrences in patients with atrial fibrillation undergoing pulmonary vein isolation (PVI).

METHODS

Between January 2012 and December 2017, data of 482 patients undergoing their first PVI were included. Sinus heart rate was recorded before (PRE), directly post-ablation (POST) and 3 months post-ablation (3 M). All patients were screened for atrial tachyarrhythmia recurrences during the one-year follow-up.

RESULTS

In the total study cohort, the mean resting sinus heart rate at PRE [mean 57.9 bpm (95% CI 57.1-58.7 bpm)] increased by over 10 bpm to POST [mean 69.4 bpm (95% CI 68.5-70.3 bpm); p < 0.001] followed by a slight decrease at 3 M [mean 67.3 bpm (95% CI 66.4-68.2 bpm)] but still remaining higher compared to PRE (p < 0.001). This pattern was observed in patients with and without recurrences at POST and 3 M (both p < 0.001 compared to PRE). However, at 3 M the mean sinus heart rate was significantly lower in patients with compared to patients without recurrences (p = 0.031). In this regard, patients with a heart rate change < 11 bpm (PRE to 3 M) or, as an alternative parameter, patients with a heart rate < 60 bpm at 3 M had a significantly higher risk of recurrences compared to the remaining patients (Hazard ratio (HR) 1.82 (95% CI 1.32-2.49), p < 0.001 and HR 1.64 (95% CI 1.20-2.25), p = 0.002, respectively).

CONCLUSION

Our study confirms the impact of PVI on cardiac autonomic function with a significant sinus heart rate increase post-ablation. Patients with a sinus heart rate change < 11 bpm (PRE to 3 M) are at higher risk for recurrences during one-year post-PVI.

Sinus heart rate post pulmonary vein ablation and long-term risk of recurrences

Aim

To investigate the association of sinus heart rate pre- and post-ablation and recurrence rates in patients undergoing catheter ablation for atrial fibrillation.

Methods

Between January 2012 and December 2017, data of 482 patients undergoing their first pulmonary vein isolation (PVI) were included. All patients were followed-up for 12 months and were screened for any atrial tachyarrhythmia. Sinus heart rate measurements were recorded before (PRE), directly post ablation (POST) and 3 months post ablation (3M).

Results

In the total study population, the mean resting sinus heart rate at PRE (mean 57.9 bpm (95% CI, 57.1–58.7 bpm)) increased by over 10 bpm to POST (mean 69.4 bpm (95% CI, 68.5–70.3 bpm); p&lt;0.001) followed by a slight decrease at 3M (mean 67.3 bpm (95% CI, 66.4–68.2 bpm)) but still remaining higher compared to PRE (p&lt;0.001). This pattern was observed in patients with and without recurrences at PRE, POST and 3M respectively (both p&lt;0.001). However, only at 3M, there was a significant difference in mean heart rate being lower in patients with compared to patients without recurrences (p=0.031). In this regard, patients with a heart rate ≥60 bpm at 3M and a heart rate change ≥11 bpm (PRE to 3M) had a favorable outcome in terms of recurrences compared to the remaining patients (HR 0.61 (95% CI, 0.44–0.84), p=0.002 and HR 0.55 (95% CI, 0.40–0.76), p&lt;0.001, respectively). These variables remained independently associated in multivariable analysis.

Conclusion

Our study confirms the impact of PVI on cardiac autonomic function with a significant heart increase post-ablation. A heart rate ≥60bpm at 3M and a heart rate change ≥11 bpm (PRE to 3M) are associated with a favorable outcome in terms of recurrences.

Funding Acknowledgement

Type of funding source: Foundation. Main funding source(s): German Research Foundation

Long-term outcome of patients with invasive electrophysiology procedure related cardiac tamponade

Aims

Iatrogenic cardiac tamponades are a rare but dreaded complication of invasive electrophysiology procedures (EPs). Their long-term impact on clinical outcomes is unknown. This study analyzed the risk of death or serious cardiovascular events in patients suffering from EP related cardiac tamponade requiring pericardiocentesis during long-term follow-up.

Methods and results

Out of 19997 invasive EPs at our university hospital between January 1998 and September 2018, all patients with EP related periprocedural cardiac tamponade were identified (n=60) and matched (1:3 ratio) to a control group (n=180). After a follow-up of 5 years, the composite primary end point - death from any cause, acute myocardial infarction, TIA/stroke and hospitalization for heart failure – occurred in significantly more patients in the tamponade than in the control group (12 patients (20.0%) vs 19 patients (10.6%); Hazard ratio (HR) 2.53 (95% CI, 1.15–5.58); p=0.021). This was mainly driven by a higher incidence of TIA/stroke in the tamponade than in the control group (HR 3.75 (95% CI, 1.01–13.97); p=0.049). Death from any cause, acute myocardial infarction and hospitalization for heart failure did not show a significant difference between the groups. Hospitalization for pericarditis occurred in significantly more patients in the tamponade than in the control group (HR 36.0 (95% CI, 4.68–276.86); p=0.001).

Conclusion

Patients with EP related cardiac tamponade are at higher risk for cerebrovascular events during the first two weeks and hospitalization for pericarditis during the first months after index procedure. Despite the increased risk for early complications tamponade patients have a good long-term prognosis without increased risk for mortality or other serious cardiovascular events.

Funding Acknowledgement

Type of funding source: Foundation. Main funding source(s): German Research Foundation

Long-term outcome of patients with invasive electrophysiology procedure-related cardiac tamponade

AIMS

Iatrogenic cardiac tamponades are a rare but dreaded complication of invasive electrophysiology procedures (EPs). Their long-term impact on clinical outcomes is unknown. This study analysed the risk of death or serious cardiovascular events in patients suffering from EP-related cardiac tamponade requiring pericardiocentesis during long-term follow-up.

METHODS AND RESULTS

Out of 19 997 invasive EPs at the Karolinska University Hospital between January 1998 and September 2018, all patients with EP-related periprocedural cardiac tamponade were identified (n = 60) and matched (1:3 ratio) to a control group (n = 180). After a follow-up of 5 years, the composite primary endpoint - death from any cause, acute myocardial infarction, transitory ischaemic attack (TIA)/stroke, and hospitalization for heart failure - occurred in significantly more patients in the tamponade than in the control group [12 patients (20.0%) vs. 19 patients (10.6%); hazard ratio (HR) 2.53 (95% confidence interval, CI 1.15-5.58); P = 0.021]. This was mainly driven by a higher incidence of TIA/stroke in the tamponade than in the control group [HR 3.75 (95% CI 1.01-13.97); P = 0.049]. Death from any cause, acute myocardial infarction, and hospitalization for heart failure did not show a significant difference between the groups. Hospitalization for pericarditis occurred in significantly more patients in the tamponade than in the control group [HR 36.0 (95% CI 4.68-276.86); P = 0.001].

CONCLUSION

Patients with EP-related cardiac tamponade are at higher risk for cerebrovascular events during the first 2 weeks and hospitalization for pericarditis during the first months after index procedure. Despite the increased risk for early complications tamponade patients have a good long-term prognosis without increased risk for mortality or other serious cardiovascular events.

Cryoablation of atrioventricular nodal re-entrant tachycardia: 7-year follow-up in 515 patients-confirmed safety but very late recurrences occur

Aims

Cryoablation is an alternative method to radiofrequency ablation for treatment of atrioventricular nodal re-entrant tachycardia (AVNRT). This study investigates the long-term safety and efficacy of cryoablation in AVNRT.

Methods and results

We studied 515 consecutive patients (317 women, mean age 50 years, range 13-89 years) undergoing a first cryoablation for AVNRT between 2003 and 2008. Ablations were performed with a 6-mm Freezor Xtra catheter. Six patients were acute failures; 494 out of 509 (97%) primarily successfully ablated patients were followed up for a mean of 7.1 years (range 2-12 years). About 11% (54/494 patients) of patients had recurrences of the index arrhythmia. Time to recurrence varied from days to 9 years; 14 patients (3%) had recurrences later than 2 years, 8 patients (2%) later than 3 years, and 6 patients (2%) later than 4 years. Recurrence rate was higher in patients with slow-slow or fast-slow AVNRT (n = 24) compared with the common slow-fast variant (25 vs. 10%; P = 0.04). Recurrence rate was not higher in patients with residual slow pathway conduction (jump with or without echo beat, n = 199, 39%). Transient atrioventricular (AV) block of the first-, second-, or third-degree during ablation was observed in 45 patients but had no impact on the risk of AVNRT recurrence. No late AV block occurred. Single vs. multiple applications or total amount of cryoenergy delivered did not differ between patients with and without recurrences.

Conclusion

Cryoablation in AVNRT is safe with a long-term efficacy of 88%; however, very late recurrences occur.

Cryoablation of substrates adjacent to the atrioventricular node: acute and long-term safety of 1303 ablation procedures

AIMS

Radiofrequency (RF) ablation is effective for ablation of atrial arrhythmias. However, RF ablation in the vicinity of the atrioventricular (AV) node is associated with a risk of inadvertent, irreversible high-grade AV block, depending on the type of substrate. Cryoablation is an alternative method. The objective was to investigate the acute and long-term risks of AV block during cryoablation.

METHODS AND RESULTS

We studied 1303 consecutive cryoablations of substrates in the vicinity of the AV node in 1201 patients (median age 51 years, range 6-89 years) on acute and long-term impairment to the AV nodal conduction system. The arrhythmias treated were AV nodal reentrant tachycardias (n=1116), paraseptal and superoparaseptal accessory pathways (n=100), and focal atrial tachycardias (n=87). In 158 (12%) procedures, cryomapping (38 cases) or cryoablation (120 cases) were stopped due to transient AV block (first-degree AV block 74 cases, second-degree AV block 67 cases, and third-degree AV block 17 cases) after which another site was tested. Transient AV block occurred within seconds of mapping up to 3 min of ablation. The incidence of AV block was similar for different substrates. In most cases, AV nodal conduction was restored within seconds but in two cases transient AV block lasted 21 and 45 min, respectively. There were no cases of acute permanent AV blocks. No late AV blocks occurred during follow-up (mean 24 months, range 6-96 months).

CONCLUSION

Cryoablation adjacent to the AV node carries a negligible risk of permanent AV block. Transient AV block during ablation is a benign finding.

Paroxysmal regular supraventricular tachycardia: the diagnostic accuracy of the transesophageal ventriculo-atrial interval

OBJECTIVE

To establish the diagnostic accuracy of the transesophageal ventriculo-atrial (VA) interval in patients with paroxysmal supraventricular tachycardia (PSVT) and normal baseline electrocardiogram (ECG).

METHODS

The transesophageal VA interval during tachycardia was recorded in 318 patients (age 45 ± 17 years, 58% female) with PSVT and a normal surface ECG between attacks. Subsequently, all patients underwent an ablation procedure establishing the correct tachycardia diagnosis.

RESULTS

AV nodal reentrant tachycardia (AVNRT), AV reentrant tachycardia through a concealed accessory pathway (AVRT), and ectopic atrial tachycardia (EAT) were found in 213, 95, and 10 cases, respectively. Receiver operating characteristic curve analysis identified an optimal cutoff for a binary categorization of AVNRT versus AVRT/EAT at ≤80 ms (area under the curve 0.891). Owing to a biphasic distribution, AVNRT was very likely at VA intervals ≤90 ms with a sensitivity, specificity, and positive predictive value (PPV) of 87%, 91%, and 95%. In the range 91-160 ms the corresponding values for AVRT were 88%, 95%, and 88% (90%, 99%, and 98% in male patients). In the small group with VA intervals >160 ms (n = 29), the diagnosis was less clear (PPV of 67% for AVNRT).

CONCLUSIONS

In patients with sudden onset regular tachycardia and a normal ECG during sinus rhythm, a transesophageal VA interval of ≤80 ms has the highest diagnostic accuracy to diagnose AVNRT versus AVRT/EAT. Overall, the biphasic distribution of VA intervals suggests considering AVNRT at 90 ms and below and AVRT between 91 and 160 ms (in particular in male patients) while the diagnosis is vague at VA intervals above 160 ms.

Predictors of long-term risk for heart failure hospitalization after acute myocardial infarction

BACKGROUND

Data on the value of baseline brain natriuretic peptide (BNP) and autonomic markers in predicting heart failure (HF) hospitalization after an acute myocardial infarction (AMI) are limited.

METHODS

A consecutive series of patients with AMI without a previous history of HF (n = 569) were followed up for 8 years. At baseline, the patients had a blood sample for determination of BNP, a 24-hour Holter recording for evaluating heart rate variability (HRV) and heart rate turbulence (HRT), and an assessment of baroreflex sensitivity (BRS) using phenylephrine test.

RESULTS

During the follow-up, 79 (14%) patients were hospitalized due to HF. Increased baseline BNP, decreased HRV, HRT, and BRS had a significant association with HF hospitalization in univariate comparisons (P < 0.001 for all). After adjusting with all the relevant clinical parameters, BNP, HRV, and HRT still significantly predicted HF hospitalization (P < 0.001 for BNP and for the short-term scaling exponent alpha(1), P < 0.01 for turbulence slope). In the receiver operator characteristics curve analysis, the area under the curve for BNP was 0.77, for the short-term scaling exponent alpha(1) 0.69, for turbulence slope 0.71, and for BNP/standard deviation of all N-N intervals ratio 0.80.

CONCLUSION

Baseline increased BNP and impaired autonomic function after AMI yield significant information on the long-term risk for HF hospitalization.

Autonomic markers as predictors of nonfatal acute coronary events after myocardial infarction

BACKGROUND

Autonomic markers, such as heart rate variability (HRV), heart rate turbulence (HRT), and baroreflex sensitivity (BRS) provide information on the risk of all-cause mortality after an acute myocardial infarction (AMI), but their value in predicting nonfatal cardiac events is not well known.

METHODS

A consecutive series of 675 patients with an AMI were followed up to 30 months. At baseline, the patients underwent a 24-hour Holter recording, and assessment of BRS using phenylephrine test. Several parameters of HRV and HRT were determined.

RESULTS

After the follow-up, 98 patients (15%) had a nonfatal acute coronary event. Among the studied variables, the short-term scaling exponent alpha1 (P = 0.002), power-law slope beta (P = 0.008), low-frequency component of HRV power spectrum (P < 0.001), turbulence slope (P < 0.001), and BRS (P < 0.001) had the strongest association with the occurrence of nonfatal acute coronary events in univariate comparisons. After adjustment with relevant clinical variables (such as age, gender, ejection fraction, functional class, medication, diabetes) in the Cox proportional hazards model, alpha1 and beta remained as statistically significant predictors of nonfatal acute coronary events (HR = 2.0 [1.2-3.2, 95% CIs, P = 0.006] for alpha1 < or = 1.025), (HR = 1.9 [1.2-3.1, P = 0.008] for beta < or =-1.507).

CONCLUSION

Several autonomic markers provide information on the risk of recurrent nonfatal coronary events after an AMI. Altered fractal heart rate behavior seems to be the strongest independent predictor of such events.

Diagnosis and treatment of menorrhagia

One-third of all women experience heavy menstrual bleeding at some point in their life. In western countries, about 5% of women of reproductive age will seek help for menorrhagia annually. Half of all women who consult for hypermenorrhea have some uterine abnormality, most often fibroids (among patients under 40 years of age) and endometrial polyps (above 40 years of age). Appropriate treatment considerably improves the quality of life of these patients, and it is important to make a rigorous assessment of the patient to provide the best treatment options. This guideline provides instructions on how to examine and treat women of fertile age who have menorrhagia. The subject's own assessment of the amount of menstrual blood loss does not generally reflect the true amount. All patients should undergo a pelvic examination and, if the menstrual pattern has changed substantially or if anaemia is present, a vaginal sonography should be carried out as the most important supplemental examination. Vaginal sonography combined with an endometrial biopsy is a reliable method for diagnosing endometrial hyperplasia or carcinoma, but it is insufficient for diagnosing endometrial polyps and fibroids; these can be diagnosed more reliably by sonohysterography or hysteroscopy. Non-steroidal anti-inflammatory drugs and tranexamic acid reduce menstrual blood loss by 20-60%, and the effectiveness of a hormonal intrauterine system (IUS) is comparable with that of endometrial ablation or hysterectomy. Cyclic progestogens do not significantly reduce menstrual bleeding of women who ovulate. Treatment should be started with one of the drug therapies, i.e. the IUS, tranexamic acid, anti-inflammatory drugs, or oral contraceptive. Drug treatment should be used and evaluated before surgical interventions are considered. With an effective training and feedback system, it is possible to organise the diagnostics, medical treatment and follow-up of heavy menstrual bleeding in the primary health care setting or in outpatient clinics, which reduces the burden on specialist health care.

Ischemia induces aggravation of baseline repolarization abnormalities in left ventricular hypertrophy: a deleterious interaction

Epidemiological studies show that left ventricular hypertrophy (LVH) and hypertension (HT) in coronary artery disease increases the risk for cardiovascular events including sudden cardiac death (SCD). According to experimental studies, myocardial hypertrophy is associated both with altered electrophysiological properties (including prolonged repolarization) and increased vulnerability to ischemia. However, human data to support a repolarization-related mechanism for the increased SCD risk has not been provided. We therefore studied 187 patients undergoing three-dimensional vectorcardiographic monitoring during coronary angioplasty. Eight parameters reflecting different aspects of ventricular repolarization were used: 1) the ST segment (ST-VM and STC-VM), 2) the T vector (QRS-T angle, Televation, and Tazimuth), and 3) the T vector loop (Tavplan, Teigenv, and Tarea). Data collection was performed at rest and at the time of maximum ischemia during coronary occlusion. The patients were divided into three groups: 33 patients with ECG signs of LVH (18 with HT), 54 with HT but without LVH signs, and 100 patients with neither. Coronary artery disease patients with LVH not only had the most abnormal baseline repolarization (as expected) but also a significantly more pronounced repolarization response during coronary occlusion, whereas HT patients had mean parameter values between LVH patients and those without neither HT nor LVH signs. Because there is a relation between increased SCD risk and repolarization disturbances in various clinical settings, the results of the present study are in agreement with animal data and epidemiological observations, although other factors than disturbed repolarization might be of importance.

SCREENING OF FSH RECEPTOR GENE MUTATION (C566T) IN AZOOSPERMIC MEN IN JAPAN

To study the genetic mutation, which could cause problems in spermatogenesis, we screened the point mutations of the FSH receptor gene (C566T) in idiopathic azoospermic men in Japan. We performed mutational analysis of the FSH receptor in 54 Japanese patients diagnosed for azoospermia with Sertoli cell-only (SCO) syndrome (n = 33), hypospermatogenesis (n = 11) and maturation arrest (n = 10). For mutation screening of the FSH receptor, polymerase chain reaction (PCR) amplification from genomic DNA with flanking intronic primers were used. On BsmI digestion, all patients demonstrated homozygous, normal exon 7 alleles with 51 and 27 bp fragments. The absence of any 78 bp fragments demonstrated that no heterozygous or homozygous mutant alleles were present in any patients. None of the 54 patients showed a C566T FSH receptor mutation. We could not confirm that the genomic mutation of the FSH receptor (C566T) is a common cause in Japanese azoospermic patients.

T vector and loop characteristics in coronary artery disease and during acute ischemia

OBJECTIVE

Three-dimensional characterization of the ventricular repolarization by the T vector and T vector loop morphology in coronary artery disease (CAD), and their response to short-term (no flow) ischemia induced by coronary occlusion during a percutaneous intervention (PCI).

BACKGROUND

The risk for sudden cardiac death is increased in conditions of acute or permanently heterogeneous ventricular repolarization, for which ischemia is a risk factor.

METHODS

Fifty-six CAD patients without visible collateral circulation were studied during an elective single-vessel PCI, and 10 healthy controls twice at rest. T vector parameters (Televation, Tazimuth, and QRS-T angle), and T loop parameters (Tarea, Tavplan, and Teigenv) were measured by vectorcardiography. ST vector magnitude (ST-VM) and its change (STC-VM) were used for reference.

RESULTS

At rest, T vector loop morphology (Tarea, Teigenv) was significantly different in CAD patients and controls, while T vector angles did not separate the groups. Ischemia induced significant changes in T loop parameters in the entire CAD group, whereas in the LAD subgroup significant changes were seen also in T vector angle. The T loop morphology was significantly different at baseline and a more pronounced response to ischemia (Tarea) was seen in patients with, than in those without, a history of hypertension.

CONCLUSION

T loop morphology, rather than the T vector angle, separated CAD patients from healthy controls. Coronary occlusion had significant impact on ventricular repolarization, as assessed by T vector and morphology analysis, and most prominently in the LAD group. Hypertensive patients appeared especially vulnerable to ischemia.

Intrauterine 10 microg and 20 microg levonorgestrel systems in postmenopausal women receiving oral oestrogen replacement therapy: clinical, endometrial and metabolic response

OBJECTIVE

The clinical and endometrial efficacy and lipid response of two different doses of intrauterine levonorgestrel were assessed in comparison with sequential oral medroxyprogesterone acetate in postmenopausal women receiving continuous oral E2-valerate.

DESIGN

One-year prospective multicentre randomised control trial.

SETTING

Four outpatient clinics in Oulu, Helsinki and Jyväskylä, Finland.

POPULATION

A total of 163 healthy volunteer postmenopausal women with climacteric complaints or already using hormone replacement therapy (HRT).

INTERVENTIONS

Subjects were randomly allocated to receive a new intrauterine system releasing 10 microg of levonorgestrel daily or an established intrauterine system (Mirena) releasing 20 microg of levonorgestrel daily or sequential oral medroxyprogesterone acetate (5mg/day, 14/30 days). All three regimens were combined with an oral daily dose of 2mg of E2-valerate.

MAIN OUTCOME MEASURES

Bleeding patterns were assessed by diaries kept by the subjects. Endometrial effects were evaluated by histologic biopsies taken at the baseline and after six and 12 months of therapy. Serum concentrations of total, HDL and LDL cholesterol, triglycerides and lipoprotein(a) were determined at the baseline and after six and 12 months of therapy.

RESULTS

Insertion of the smaller 10 microg levonorgestrel system was easy in 70% and difficult in 4% and that of Mirena was easy in 46% and difficult in 21% of the subjects. After six months of therapy, 43 (95.6%) of the 47 subjects receiving 10 microg levonorgestrel and 54 (98.2%) of the 55 subjects receiving 20 microg levonorgestrel had no bleeding, while the sequential medroxyprogesterone acetate regimen produced typical cyclic withdrawal bleedings. Endometrial hyperplasia was not observed in any of the treatment groups during the 12-month study. After 12 months of therapy, strong endometrial suppression was found in 46/47 and 55/55 of the subjects receiving 10 microg and 20 microg of levonorgestrel, respectively, while the endometrium was proliferative in 18/47 of the subjects in the medroxyprogesterone acetate group. Serum total cholesterol decreased in all treatment groups. HDL cholesterol increased in women receiving medroxyprogesterone acetate or the smaller intrauterine dose of levonorgestrel.

CONCLUSIONS

Both intrauterine doses of levonorgestrel provided good endometrial protection in postmenopausal women on oestrogen replacement therapy. The advantage of the 10 microg system with a smaller size is the easier insertion of the system and a minimal attenuation of the favourable effects of oral oestrogen on the serum lipid profile.

The identification of secreted carbonic anhydrase VI as a constitutive glycoprotein of human and rat milk

In addition to essential nutrients, human milk contains several classes of bioactive factors such as enzymes, hormones, and growth factors, many of which are implicated in infantile growth and development. Secretory carbonic anhydrase isoenzyme VI (CA VI) has been identified earlier as an essential component of mammalian saliva, and we demonstrate here by using biochemical and immunohistochemical techniques that it is also an elementary component of milk. The 42-kDa glycopolypeptide purified from human milk in CA inhibitor affinity chromatography shared 100% homology with salivary CA VI in the protein sequence analysis (40% coverage), and its digestion with PNGase F resulted in a polypeptide backbone similar in size to salivary CA VI. Quantification of CA VI in milk by using a time-resolved immunofluorometric assay revealed an approximately eight-times-higher concentration in human colostrum than in mature milk, the latter corresponding to the levels previously detected in human saliva. The high concentration in the colostrum, in particular its functional and structural stability in an acidic milieu, and its growth-supporting role in the taste buds suggest that milk CA VI is an essential factor in normal growth and development of the infant alimentary tract.

One versus two embryo transfer after IVF and ICSI: a randomized study

BACKGROUND

The main reason for adverse treatment outcome in assisted reproduction is the high rate of multiple pregnancies. The only strategy to avoid dizygotic twins is to transfer one embryo at a time.

METHODS

A total of 144 women, who had had at least four good quality embryos available after IVF/intracytoplasmic sperm injection (ICSI) and who had no more than one previous failed treatment cycle, were randomized to have either one or two embryos transferred. The treatment outcomes including those after frozen embryo transfer were compared between these groups.

RESULTS

The clinical pregnancy rate per transfer was 32.4% in the one embryo transfer group and 47.1% in the two embryo transfer group, the difference being not significant. Eleven twin deliveries (n = 39) occurred in the two embryo transfer group and there was one pair of monozygotic twins in the one embryo transfer group. The cumulative pregnancy rate per patient after transfer of fresh and frozen embryos was 47.3% in the one embryo transfer group and 58.6% in the two embryo transfer group.

CONCLUSIONS

Our results indicate that among women who have good quality embryos in their first IVF/ICSI, good treatment results can be achieved. They support the idea of changing embryo transfer policy towards one embryo transfer without any remarkable decrease in the success rate, while dizygotic twins can be avoided.

Identification of carbonic anhydrase XII as the membrane isozyme expressed in the normal human endometrial epithelium

Although previous studies demonstrated carbonic anhydrase (CA) activity in the human endometrium, the CA isozyme(s) responsible for this activity has not been established. In this report, we provide the first evidence that the CA isozyme XII, a recently identified transmembrane isozyme that is expressed in normal kidney and greatly overexpressed in some renal cancers, is present in endometrium. We show by immunohistochemistry that CA XII is expressed in the basolateral plasma membrane of epithelial cells of normal human endometrium. Expression of CA XII in uterus was confirmed by Northern blotting. Detergent-solubilized CA XII was isolated from human endometrium by inhibitor affinity chromatography and characterized by isoelectric focusing and Western blot as a polypeptide with a pI of 6.3. The high expression of CA XII in the endometrial epithelium suggests that it may be functionally linked to the pH-dependent events in spermatozoa that precede fertilization. Its basolateral location and extracellular active site could also allow it to influence the morphological changes in endometrium that occur during the menstrual cycle.

The prevalence of polycystic ovaries in healthy women

BACKGROUND

To study the prevalence of polycystic ovaries (PCO) in women of reproductive age.

METHODS

A total of 189 healthy volunteers aged 20-45 years were examined. The subjects were divided into two groups according to age: < or =35 and > or =36 years. Transvaginal ultrasonography was performed and blood samples were collected on cycle day 1-6.

RESULTS

The prevalence of PCO in the entire study population was 14.2% (27/189). In the age group of < or =35 years the prevalence was 21.6% (19/88) and in the age group of > or =36 years 7.8% (8/101). Compared to women with normal ovaries, those with PCO had significantly higher serum testosterone (T) concentrations. Women with PCO tended to have lower serum FSH concentrations and higher LH/FSH ratios than controls. Women with PCO had significantly more irregular cycles (44% vs. 19%, p=0.001) and problems in conceiving (25.9% vs. 9.2%, p=0.01) than women with normal ovaries.

CONCLUSIONS

The findings demonstrate that the prevalence of PCO in healthy women varies with age, being more common among women aged < or =35 years than in those aged > or =36 years. Although the hormonal parameters and clinical findings among women with PCO mimicked those of PCOS, it remains unclear if these women will later develop full-blown syndrome.

Placental mitochondrial DNA and respiratory chain enzymes in the etiology of preeclampsia

OBJECTIVE

To evaluate the occurrence of the most common mutations and deletions in mitochondrial DNA and deficiencies in the enzyme complexes of the mitochondrial respiratory chain in placentas from preeclamptic women.

METHODS

Mitochondria were isolated from the placentas of 17 preeclamptic or 25 control women, and the activities of mitochondrial respiratory chain complexes were measured. Deletions and three common point mutations of mitochondrial DNA were searched for by the Southern blot and polymerase chain reaction (PCR) methods from the same placentas.

RESULTS

Mean (+/- standard deviation) mitochondrial respiratory chain enzyme complex activities in placentas on protein basis (nmol/min/mg of protein) were similar in preeclamptics and controls (nicotinamide adenine dinucleotide, reduced form-ubiquinone oxidoreductase 25.84 +/- 9.29 versus 31.02 +/- 7.52; nicotinamide adenine dinucleotide, reduced form-cytochrome-c oxidoreductase 77.88 +/- 42.24 versus 104.06 +/- 56.73; succinate-cytochrome-c oxidoreductase 57.90 +/- 13.83 versus 64.44 +/- 20.16; cytochrome-c oxidase 106.43 +/- 35.46 versus 128.37 +/- 48.64, respectively) and they were similar also when referenced to the mitochondrial marker enzyme citrate synthase. The sample sizes in both patient and control groups were found to be large enough by post hoc test. Large-scale deletions or the common 5-kb and 7.4-kb deletions were not detected, even at the sensitivity level of PCR. The three most common point mutations were not found in either control or preeclamptic placental samples.

CONCLUSION

Common mitochondrial DNA mutations seem to play no major role in the universal etiology of preeclampsia, as assessed by analysis of the mitochondrial genome and respiratory chain enzyme activities in vitro. This does not exclude possible alterations in the energy state of the preeclamptic placenta.

Human 17beta-hydroxysteroid dehydrogenase type 2 messenger ribonucleic acid expression and localization in term placenta and in endometrium during the menstrual cycle

According to the current hypothesis, 17beta-hydroxysteroid dehydrogenases (17HSDs) regulate the extent of estrogen influence in the endometrium by converting estradiol (E2) locally into a biologically less active sex steroid, estrone (E1), and vice versa. Recently, we have shown that both 17HSD type 1 and type 2 are expressed in the human endometrium, and in the present work, using in situ hybridization, we show that 17HSD type 2 is localized in the glandular epithelial cells as previously shown for the type 1 enzyme, but in contrast to type 1, the expression of type 2 is highest at the end of the cycle. Hence, we hypothesize that the differential expression of the two 17HSD enzymes, with opposite activities in same cell types, could modulate intracellular E2 concentrations during the end of the luteal phase of the menstrual cycle. We further analyzed the expression of 17HSD type 1 and type 2 mRNAs in term human placenta. Expression of 17HSD type 1 mRNA was detected in the syncytiotrophoblasts, and signals for type 2 mRNA were found inside the villi, corresponding to cytotrophoblasts. The expression of 17HSD type 2 in the placenta may serve to maintain the presence of inactive sex steroids and attenuate the formation of biologically potent androgens and estrogens.

Mutation in the follicle-stimulating hormone receptor gene causes hereditary hypergonadotropic ovarian failure

Hypergonadotropic ovarian dysgenesis (ODG) with normal karyotype is a heterogeneous condition that in some cases displays Mendelian recessive inheritance. By systematically searching for linkage in multiplex affected families, we mapped a locus for ODG to chromosome 2p. As the previously cloned follicle-stimulating hormone receptor (FSHR) gene had been assigned to 2p, we searched it for mutations. A C566T transition in exon 7 of FSHR predicting an Ala to Val substitution at residue 189 in the extracellular ligand-binding domain segregated perfectly with the disease phenotype. Expression of the gene in transfected cells demonstrated a dramatic reduction of binding capacity and signal transduction, but apparently normal ligand-binding affinity of the mutated receptor. We conclude that the mutation causes ODG in these families.

Apoptosis in testis germ cells: developmental changes in gonadotropin dependence and localization to selective tubule stages

Recent studies have demonstrated apoptotic DNA fragmentation in the testis of immature rats deprived of gonadotropins. However, the exact cell type undergoing apoptosis during testis development and the age differences of gonadotropin dependence of testis cell apoptosis are unclear. The present study used gel fractionation and in situ methods to quantitate developmental changes of testis cell DNA fragmentation and to localize the specific cell type affected in developing rats with and without treatment with a GnRH antagonist. Apoptotic DNA fragmentation in whole testis was measured in rats between 8-70 days of age. A gradual increase (1.8- to 2.0-fold) in testis apoptotic DNA fragmentation was seen in rats between 16-28 days of age, compared with 8-day-old animals, followed by a decrease in adult animals. To study gonadotropin dependence of testicular apoptosis, serum FSH and, to a lesser extent, LH were suppressed by treatment with a long-acting GnRH antagonist (azaline-B, 250 micrograms/kg body wt, two injections at 2-day intervals). Pretreatment with the GnRH antagonist increased apoptotic DNA fragmentation in rats between 16-32 days of age but not in younger and adult animals demonstrating an age-related change in gonadotropin dependence. To identify the exact testis cell type undergoing apoptosis, in situ analysis of DNA fragmentation was performed. In rats at 16-24 days of age, spermatocytes in selected tubules were found to have increased DNA fragmentation. In contrast, neither Leydig cells nor Sertoli cells were affected. In 32-day-old and adult animals, increased DNA fragmentation was seen in early primary spermatocytes of some tubules. Treatment with GnRH antagonist increased the number of cells with DNA fragmentation as well as percentage of tubules affected. In animals between 16-32 days of age, meiotic spermatocytes were labeled, whereas early spermatids were also labeled in 24- and 32-day-old animals. In adult animals, the level of apoptotic DNA fragmentation was not affected by GnRH antagonist treatment. However, DNA isolated from specific stages of the seminiferous tubules of adult animals showed stage-specific changes of apoptotic DNA fragmentation with 2-fold higher levels found in stages I and XII-XIV compared with stage VIII. In situ analysis of adult testis demonstrated that spermatocytes were the major cell type affected. In conclusion, the present study demonstrated that at least three factors determine the onset of apoptosis of the male germ cells: 1) the developmental stage of the animal; 2) serum levels of gonadotropins, especially FSH; and 3) specific stage of the seminiferous epithelial cycle. The present approach provides the basis for future analysis of the role of gonadotropins and other factors in the regulation of testis cell degeneration in normal and pathological states.

Photoperiod regulates testis cell apoptosis in Djungarian hamsters

Reproductive activity in the Djungarian hamster is controlled by seasonal variations in day length. Exposure to long days stimulates testis development, while exposure to short days induces testis regression. We recently found that testis regression after gonadotropin deprivation in rats is associated with increases in apoptosis. Here we sought to determine whether or not apoptosis is associated with the testis regression and/or recrudescence that occurs naturally in seasonally breeding mammals. Newborn male hamsters were maintained on long days (16L:8D) until 3 wk of age before being transferred to short days (8L:16D). Following decreases in serum FSH within 3 days of exposure to short days, testis weight decreased by 52% at Day 10, reaching a 70% decrease after 21 days. Analysis of testis cell DNA fragmentation showed a 4.9-fold increase of low-molecular-weight DNA as early as 5 days after transfer to short days; this was followed by a time-dependent decrease. The observed increases in testis cell apoptosis were correlated with decreases in serum testosterone, but decreases in Leydig cell LH receptor content were delayed. In a second study, 6-wk-old hamsters with regressed testes due to a 3-wk exposure to short days were transferred back to long days. After increases in serum FSH within 3 days of photostimulation, a 2-fold elevation in testis weight was found at Day 5. The increase in testis weight was associated with a 65% decrease of testis apoptosis within 5 days of photostimulation. Also, increases in serum testosterone and LH receptor content were observed after 5 and 10 days of exposure to long days, respectively.(ABSTRACT TRUNCATED AT 250 WORDS)