P331Effect of exercise stress test on platelet function in patients with recent acute myocardial infarction

Background

Exercise-based cardiac rehabilitation for coronary artery disease (CAD) is associated with lower cardiovascular mortality. On the other hand, acute strenuous exercise has been linked to cardiovascular complications such as acute myocardial infarction (AMI) and sudden cardiac death. One of the pathophysiological mechanisms involved in these outcomes might be an increase in platelet aggregability after exercise. Although previous studies showed higher platelet aggregability after exercise among stable CAD patients on aspirin treatment, there is no data regarding the effect of exercise on platelet activity in post-AMI patients on dual anti-platelet therapy (DAPT).

Purpose

To evaluate the effect of high-intensity exercise on platelet aggregability in sedentary post-AMI patients on DAPT.

Methods

Platelet function was analyzed immediately before and after maximal cardiopulmonary exercise test (CPET) on cycle ergometer utilizing a personalized ramp protocol and aiming to achieving peak exercise in around 10 min. The CPET was done within 31±4 days after uncomplicated AMI. Platelet aggregability was assessed by Multiplate®ADPtest (MP-ADP) and Multiplate® ASPItest (MP-ASPI) measured as area under the curve (AUC). Reticulated platelets were measured concomitantly to MP-ADP e MP-ASPI using a fully automated flow cytometer (Sysmex XN-2000®) to determine absolute immature platelet count (IPC) per 103/microliter. Continuous variables were expressed as means ±standard deviation or as median and 25th–75th percentiles if not Gaussian distributed. Comparisons between the pre- and post-CPET assessments were performed using Wilcoxon signed rank test.

Results

We analyzed 81 sedentary patients (mean age 58.3±10.1 years-old, 76.5% men) after AMI (50.6% with ST-elevation myocardial infarction, mean left ventricular ejection fraction after index event 55±11.7%, 98.8% on statin and 85.5% on beta-blocker treatment). Platelet aggregability, either by MP-ADP or MP-ASPI, and IPC were significantly increased after CPET (table).

Platelet function after CPET Before CPET After CPET p-value Multiplate® ADPtest (AUC) – median (25th–75th percentiles) 32.0 (22.0–48.5) 37.0 (26.0–55.2) 0.003 Multiplate® ASPItest (AUC) – median (25th–75th percentiles) 17.0 (12.7–22.0) 22.0 (16.7–28.0) <0.001 Immature platelet count (103/microliter) – median (25th–75th percentiles) 9.5 (6.8–13.8) 9.6 (6.6–16.5) 0.006 CPET: cardiopulmonary exercise test; AUC: area under the curve.

Conclusion

On this post-AMI population, platelet was hyperactivated after exercise stress test despite the use of DAPT. These findings suggest that, even when properly treated, post-AMI patients might be at higher risk of ischemic complications after high-intensity exercises, reinforcing the importance of tailoring exercise prescription in this population.

Acknowledgement/Funding

Sao Paulo Research Foundation, FAPESP

Radiofrequency catheter ablation in drug refractory maternal supraventricular tachycardias in advanced pregnancy

BACKGROUND

Treatment of maternal tachyarrhythmias in pregnancy is a major clinical issue. Pharmacological treatment raises important concerns regarding partial efficacy and side effects. Radiofrequency ablation of arrhythmogenic substrate has rarely been performed during pregnancy because of the fetal risks related to x-ray exposure and potential fetomaternal procedural complications.

CASES

Three women affected by supraventricular tachycardias refractory to pharmacological therapy underwent successful radiofrequency catheter ablation at 29 to 30 weeks' pregnancy. All patients had cesarean delivery of newborns with normal Apgar scores.

CONCLUSION

Radiofrequency catheter ablation is an effective treatment of drug refractory maternal supraventricular tachycardias in advanced pregnancy. Further studies are required to establish its long-term fetal safety.

Can Joel-Cohen incision and single layer reconstruction reduce cesarean section morbidity?

OBJECTIVE

To compare an innovative cesarean section based on Joel-Cohen incision with the traditional Pfannenstiel technique in terms of operative data and post-operative recovery.

METHOD

Out of 158 randomized patients, 83 patients underwent the innovative cesarean section (Joel-Cohen incision, one-layer locked uterine suture, no peritoneization) and 75 the traditional operative approach (Pfannenstiel incision, double layer closure of the uterus, visceral and parietal peritoneization). Operative data and post-operative morbidity were compared; sample size was calculated to detect a 13% difference in the occurrence of post-operative fever with a statistical power of 80%.

RESULT

Post-operative fever was not different in the two groups. Total operating time was shorter with the innovative technique: 31.6 +/-1.38 min vs. 44.4+/-1.44 (P=0.0001) and fewer sutures were used: 3.6+/-0.13 vs. 6+/-0.13 (P=0.001). Patients operated by the new technique began moving sooner and intestinal function restarted earlier.

CONCLUSION

The proposed technique made for shorter operating times and faster recovery but no decrease in puerperal morbidity.

Human papillomavirus with co-existing vulvar vestibulitis syndrome and vestibular papillomatosis

OBJECTIVE

The role of HPV infection in cases of vulvar papillomatosis and vulvar vestibulitis syndrome is still unclear and data from the literature is controversial. In this study we intended to investigate the prevalence of viral infection, with a multidisciplinary approach, in cases with a co-existence of the two patterns.

METHOD

Sixteen consecutive cases with diagnosis of vulvar vestibulitis syndrome and co-existence of vestibular papillomatosis were enrolled in the study and investigated by the means of vulvar cytology, vulvoscopy, histology, ViraPap and Polymerase Chain Reaction.

RESULT

Cytology, vulvoscopy and histology did not demonstrate suitable accuracy for the diagnosis. Viral DNA identification revealed two (12.50%) positive cases using PCR and one (6.25%) positive case with ViraPap.

CONCLUSION

The results of the present investigation indicate that even in cases of co-existing vulvar papillomatosis and severe vulvar vestibulitis syndrome, the prevalence of HPV infection is too low to be considered causal.

Ca2+ dependence of gluconeogenesis stimulation by glucagon at different cytosolic NAD(+)-NADH redox potentials

The influence of Ca2+ on hepatic gluconeogenesis was measured in the isolated perfused rat liver at different cytosolic NAD(+)-NADH potentials. Lactate and pyruvate were the gluconeogenic substrates and the cytosolic NAD(+)-NADH potentials were changed by varying the lactate to pyruvate ratios from 0.01 to 100. The following results were obtained: a) gluconeogenesis from lactate plus pyruvate was not affected by Ca(2+)-free perfusion (no Ca2+ in the perfusion fluid combined with previous depletion of the intracellular pools); gluconeogenesis was also poorly dependent on the lactate to pyruvate ratios in the range of 0.1 to 100; only for a ratio equal to 0.01 was a significantly smaller gluconeogenic activity observed in comparison to the other ratios. b) In the presence of Ca2+, the increase in oxygen uptake caused by the infusion of lactate plus pyruvate at a ratio equal to 10 was the most pronounced one; in Ca(2+)-free perfusion the increase in oxygen uptake caused by lactate plus pyruvate infusion tended to be higher for all lactate to pyruvate ratios; the most pronounced difference was observed for lactate/pyruvate ratio equal to 1. c) In the presence of Ca2+ the effects of glucagon on gluconeogenesis showed a positive correlation with the lactate to pyruvate ratios; for a ratio equal to 0.01 no stimulation occurred, but in the 0.1 to 100 range stimulation increased progressively, producing a clear parabolic dependence between the effects of glucagon and the lactate to pyruvate ratio. d) In the absence of Ca2+ the relationship between the changes caused by glucagon in gluconeogenesis and the lactate to pyruvate ratio was substantially changed; the dependence curve was no longer parabolic but sigmoidal in shape with a plateau beginning at a lactate/pyruvate ratio equal to 1; there was inhibition at the lactate to pyruvate ratios of 0.01 and 0.1 and a constant stimulation starting with a ratio equal to 1; for the lactate to pyruvate ratios of 10 and 100, stimulation caused by glucagon was much smaller than that found when Ca2+ was present. e) The effects of glucagon on oxygen uptake in the presence of Ca2+ showed a parabolic relationship with the lactate to pyruvate ratios which was closely similar to that found in the case of gluconeogenesis; the only difference was that inhibition rather than stimulation of oxygen uptake was observed for a lactate to pyruvate ratio equal to 0.01; progressive stimulation was observed in the 0.1 to 100 range. f) In the absence of Ca2+ the effects of glucagon on oxygen uptake were different; the dependence curve was sigmoidal at the onset, with a well-defined maximum at a lactate to pyruvate ratio equal to 1; this maximum was followed by a steady decline at higher ratios; at the ratios of 0.01 and 0.1 inhibition took place; oxygen uptake stimulation caused by glucagon was generally lower in the absence of Ca2+ except when the lactate to pyruvate ratio was equal to 1. The results of the present study demonstrate that stimulation of gluconeogenesis by glucagon depends on Ca2+. However, Ca2+ is only effective in helping gluconeogenesis stimulation by glucagon at highly negative redox potentials of the cytosolic NAD(+)-NADH system. The triple interdependence of glucagon-Ca(2+)-NAD(+)-NADH redox potential reveals highly complex interrelations that can only be partially understood at the present stage of knowledge.

Prognostic value of pathological patterns of lymph node positivity in squamous cell carcinoma of the vulva stage III and IVA FIGO

Lymph node positivity in invasive squamous cell vulvar cancer implies a severe decrease in survival rates. Pathological lymph node positivity covers a wide range of metastatization patterns. In the present investigation the nodal positivity of 53 patients affected by Stage III and IVA invasive vulvar squamous cell carcinoma has been carefully evaluated and correlated with survival. Number, size of the metastasis inside the node, intracapsular or extracapsular site of the metastasis, and immune response of the positive nodes were considered. Cancer-related survival has been obtained for the whole study group (53 cases), for the patients with monolateral node positivity (36 cases), and for the patients showing only one positive node (19 cases). The diameter and the site of the metastasis were significantly correlated with survival in all three groups studied. Patients showing an intracapsular positivity or a size of metastasis less than 5 mm had a 5-year cancer-related survival of almost 90%, while patients showing a metastasis larger than 15 mm or an extracapsular site had a 20% survival. The results demonstrate that patients affected by invasive squamous cell vulvar cancer with positive nodes can be divided into two groups with a significantly different survival according to the histopathological pattern of lymph node invasion.