Sex differences in implantable cardiac defibrillator decision: myth or fact?

Introduction

Previous studies have found sex differences in implantable cardiac defibrillator (ICD) implantation counseling, especially in primary prevention. Possible explanations to this phenomenon have been described: under-representation of women in clinical trials, patient's preferences, lower overall sudden cardiac death risk in women compared to men, higher prevalence of non-ischemic dilated cardiomyopathy (DCM) in women and better response to cardiac resynchronization therapy in this population. Nevertheless, this gap appears to narrow in most recent registries.

Purpose

Our aim is to asses if there is still sex discrimination in ICD counseling by comparing ICD implantation between men and women.

Methods

A single-centre retrospective registry of 160 patients with a reduced left ventricle ejection fraction (LVEF ≤35%) found in a routine transthoracic echocardiogram (TTE) from January 2019 to June 2020. Inclusion and exclusion flow chart is described in Picture 1. Data collected included demographic, clinical and echocardiographic characteristics. Date of heart disease diagnosis, earliest date of LVEF ≤35% diagnosis (with TTE or cardiac magnetic resonance) and date of death when applicable were recorded. Cardiac resynchronization devices with ICD function were also considered for the analysis. In ICD carriers, implantation date and type of prevention for indication were collected. ICD implants and deaths up to December 31, 2020 were included for the analysis.

Results

Basal characteristics are described in Picture 2. The mean age was 67.5 years and 24.4% of the population were women. Ischemic etiology was the most frequent etiology in the overall population and in the male group. In women, DCM was the most common etiology.

Sixty-eight patients carried an ICD. No significant differences between both sexes, neither globally nor according to the implant indication (primary vs. secondary prevention) were observed.

In the subgroup analysis of patients with ICD, there were no significant differences in the number of devices between men and women, neither in ischemic or non-ischemic etiology. In primary prevention, there was a non-significant trend towards earlier implantation of the device in women (1.4 years vs 3.4 years, p=0.008) since the diagnosis of LVEF ≤35%.

In patients without ICD (n=92), the mean age was significantly higher (72.5 years vs. 60.8 years, p<0.0001) and similar in both sexes (women 74.6 years, men 71.8 years, p=0.414).

Conclusions

Despite under representation of women in pur population, we could not find differences in ICD implantation decision based on gender, even considering differences in underlying cardiomyopathy. There was no delay in implantation depending on sex, and even the trend was towards earlier implantation in women.

Funding Acknowledgement

Type of funding sources: None. Inclusion and exclusion flow chartBasal characteristics

Comparative Effects of Dopaminergic Agonists on Cardiovascular, Renal, and Renin-Angiotensin Systems in Hypertensive Patients

The role of dopaminergic receptors on renal function has been extensively studied. Recently dopaminergic receptor has been classified in two subtypes D1 and D2, which seem to have different modulatory function. However, the role of dopaminergic receptors on cardiovascular function and more specifically the potential role of dopaminergic agonists as antihypertensive agents has not yet been clarified. Nine outpatients with mild and moderate hypertension were studied in the Cardiology Service of Vargas Hospital with a D1 agonist, piribedil, at 50-100 mg/day, orally, for 8 weeks, and with a D2 agonist, bromocriptine, at 2.5 - 5 mg/day, orally, for an another 8 weeks by using a placebo comparative crossover design. Piribedil reduced blood pressure with a modest increase in heart rate, plasma renin activity, and of plasma aldosterone, and an important increment of renal function. Bromocriptine reduced blood pressure with a decrease in heart rate and plasma aldosterone without altering renal function. There was no orthostatic hypotension with either agent. The authors conclude that activation of dopaminergic D1 receptor induces a vasodilatory and antihypertensive effect with a reflex increase in sympathetic tone, whereas activation of dopaminergic D2 receptor induces a decrease in sympathetic tone, probably due to a decrease in norepinephrine release at adrenergic endings. The potential effect of these compounds as antihypertensive agents is of great interest because blood pressure reduction can be induced by a new mechanism, i.e. activation of dopaminergic receptors which results in a decrease of the renin angiotensin system or a vasodilatory action.(ABSTRACT TRUNCATED AT 250 WORDS)

Drin pesticides removal from aqueous solutions using acid-treated date stones

This work describes the potential applicability of chemically and thermally treated date stones for removing drin pesticides (aldrin, dieldrin and endrin) from aqueous solutions. The effect of several parameters, such as sorbent particle size, adsorbent dose, shaking speed, shaking time, concentration of pesticide solution and temperature, was evaluated by batch experiments. Pesticide determination was carried out using stir bar sorptive extraction and gas chromatography coupled with mass spectroscopy. Maximum removal efficiency (93%) was reached using 0.1 g of acid-treated date stones (ATDS) (63-100 microm) and 100 mL of aldrin (0.5 mg L(-1)). The removal efficiency of drin pesticides decreased in the order of aldrin, dieldrin and endrin, and decreased as the temperature rose. Adsorption data were processed according to various kinetic models. Lagergren and Morris-Weber equations were applied to fit the kinetic results. The second order model was the most suitable on the whole, and intra-particle diffusion was found to be the rate-controlling the adsorption process. According to adsorption kinetic data, 3.5h were considered as the equilibrium time for determining adsorption isotherms. Adsorption data were analyzed by the Langmuir, Freundlich and Dubinin-Radushkevich adsorption approaches. Experimental results showed that the Freundlich isotherm model best described the adsorption process. In addition, thermodynamic parameters such as DeltaH, DeltaS and DeltaG were calculated. Negative values of DeltaH and DeltaG indicate the exothermic and spontaneous nature of pesticide adsorption on ATDS.

Removal of prioritary pesticides contamining r'mel ground water by using organic waste residues

This study evaluated pesticide contamination of R'mel ground water located in northwest Morocco. The study area is densely populated and thriving, with intensive agriculture. Various techniques, including stir bar sorptive extraction (SBSE) and gas chromatography with mass spectroscopy detection (GC-MS), were used for the quantitative determination of 13 pesticides including alachlor, aldrin, atrazine, chlorpyrifos, chlorfenvinphos, dieldrin, alpha-endosulfan, endrin, hexachlorobenzene, beta-HCH, gamma-HCH (lindane), simazine and trifluralin. The survey results showed that contamination by pesticide residues is widespread in the area. With the exception of atrazine, the average concentrations were all below the regulatory limits established by the European Union. The potential of ten natural organic substances to eliminate pesticides included in the European Water Framework Directive was evaluated. The absorbents with the highest removal efficiency were date and olives stones and, to a Lesser degree, Raphanus raphanistrum and Cistus ladaniferus. The adsorption tests gave very satisfying results and pointed to the possible application of these supports as ecoLogical remediation techniques to prevent pesticide pollution of aquatic ecosystems.

Comprehensive ab initio thermodynamic treatment of impurities in ordered alloys: application to boron in B2 Fe-Al

A rigorous description of impurities in nearly stoichiometric ordered systems, relying on independent-point-defect thermodynamics and density-functional-theory ab initio calculations, is presented and applied to the study of the equilibrium point defect structure of Fe-Al-B alloys in the B2 composition domain (x(Al) approximately 50 at. %, x(B) approximately 0), including the influences of (i) magnetism and (ii) the local density approximation (LDA) or generalized gradient approximation (GGA) exchange-correlation functionals. Whatever the alloy composition, B substitutes for Al, except in the nonmagnetic GGA scheme predicting a switch towards interstitial occupancy for sufficient Al contents.

Haemodynamic effects of enalapril, a new converting enzyme inhibitor, in hypertensive patients

The haemodynamic effects of enalapril (EN), a new, long-acting, nonsulphhydryl converting enzyme inhibitor, were evaluated by non-invasive methods in 10 adult patients with mild to moderate essential hypertension (EH). Patients were randomly assigned, double blind to 2 treatment groups (EN 20 mg o.d. or 10 mg b.d.) for 4 weeks, and were crossed over to the other dosage regimen after a 2-week washout period. Measurements included mean arterial pressure (MAP), heart rate (HR), cardiac output (CO), limb blood flow (LBF), plasma aldosterone (ALD), plasma renin activity (PRA) and systolic time intervals (STI). Both regimens (b.d. and o.d.) significantly reduced MAP (15.3% and 16.3%, respectively), total peripheral resistance (20.3% and 21.8%, respectively), limb vascular resistance (24.1% and 24.9%) and ALD (33.5% and 36.9%) and increased CO (7.8% and 8.7%), LBF (10.9% and 11.6%) and PRA (10.4% and 9.5%). No significant change was observed in HR or STI. EN 20 mg o.d. or 10 mg b.d. reduced arterial pressure to a similar extent through a fall in total peripheral resistance. An increase in CO was also observed.

Effects of prazosin and alphamethyldopa on blood lipids and lipoproteins in hypertensive patients

The effects of prazosin and alphamethyldopa on blood lipids and lipoproteins were assessed in 20 patients with mild or moderate arterial hypertension. Parameters measured included serum cholesterol (CHO), triglycerides (TG), high density lipoprotein-cholesterol (HDL-CHO), insulin (I), glucose (G), and non-esterified fatty acids (NEFA). Prazosin -4 mg/day for 6 weeks in hydrochlorothiazide-treated patients lowered blood pressure by 18.6/17.2 (systolic/diastolic pressure) mmHg. There was a significant decrease in CHO (-5.8%), in I (-16.5%), and in NEFA (-3.0%), and a significant increase in HDL-CHO (+15.5%). Alphamethyldopa 250-750 mg/day for 6 weeks in hydrochlorothiazide-treated patients lowered blood pressure by 18.8/14.6 (systolic/diastolic pressure) mmHg, accompanied by a non-significant decrease in CHO and TG, and significant increases in HDL-CHO (+10.3%), G (+8.5%) and NEFA (+6.4%). Thus, prazosin appears to have a more beneficial effect on blood lipids and lipoproteins than alphamethyldopa.

Systemic and cardiac haemodynamic interactions between guanfacine and hydrallazine in hypertensive patients

The effect of guanfacine and hydrallazine on cardiovascular haemodynamics and on sympathetic nervous activity has been studied in 16 patients with essential hypertension. Two groups of patients were investigated: in Group A guanfacine brought the blood pressure back to normal (diastolic blood pressure less than or equal to 90 mmHg), and in Group B diastolic blood pressure was greater than 90 mmHg and required the addition of hydrallazine. Guanfacine significantly decreased heart rate, plasma renin activity and urinary excretion of noradrenaline, without altering cardiac contractility. In Group B, guanfacine 2 to 6 mg/day produced a significant decrease in blood pressure from 178.7/112.4 to 164.4/102.9 mmHg and in heart rate from 77.1 to 62.7 beats/min after 4 weeks of treatment. Guanfacine did not significantly alter preejection period, cardiac output or total peripheral resistance. Hydrallazine 50 to 300 mg/day caused a further reduction in blood pressure from 164.4/102.9 to 150.7/90.2 mmHg and an increase in heart rate from 62.7 to 72.1 beats/min. Limb blood flow was increased from 4.55 to 5.93 ml/100 g/min and limb vascular resistance was decreased from 39.55 to 23.6 mmHg 100 g X min/ml. Hydrallazine also caused a slight increase in plasma renin activity and urinary excretion of noradrenaline. It is concluded that guanfacine is a useful agent to block a hydrallazine-induced increase in sympathetic nervous activity.

Cardiovascular hemodynamic interactions between clonidine and minoxidil in hypertensive patients

The systemic, cardiovascular hemodynamic and biochemical interactions between clonidine and minoxidil were studied in ten patients with refractory and/or accelerated hypertension. Clonidine in oral doses of 150 to 900 micrograms/day decreased mean blood pressure (MAP) 18.6 mm Hg (p less than 0.01), average heart rate (HR) 16.4 bpm (p less than 0.01), limb blood flow 1.63 ml/100 g min (p less than 0.05), plasma renin activity (PRA) 1.13 ng/ml/hr (p less than 0.025), and urinary noradrenaline excretion rate 16.45 micrograms/24hr (p less than 0.05). Clonidine increased the preejection period index (PEPI) 12.4 msec ( p less than 0.001), but did not alter cardiac index (CI), total peripheral resistance index (TPRI), limb vascular resistance nor dopamine beta-hydroxylase activity. When minoxidil in oral doses of 5 to 22.5 mg was added, a further decrease in MAP of 24.2 mm Hg (p less than 0.01) was observed; PEPI decreased 20.6 msec (p less than 0.01), limb blood flow decreased 13.2 mm Hg/min 100 g/ml (p less than 0.05), and total peripheral resistance index decreased 13.3 mm Hg/min m2/L (p less than 0.05). Minoxidil increased average heart rate 8.2 bpm (p less than 0.05), PRA 1.68 ng/ml/hr (p less than 0.05) and urinary noradrenaline excretion rate 5.0 micrograms/24 hr (p less than 0.01). Limb blood flow, cardiac index and dopamine beta hydroxylase activity were not significantly altered by minoxidil. Neither clonidine nor minoxidil affected cardiovascular responses to treadmill exercise. We concluded that clonidine is a useful alternative agent to block a minoxidil-induced increase in sympathetic nervous activity.

Systemic and cardiac hemodynamic interactions between clonidine and minoxidil

We examined the hemodynamic interaction between clonidine, a centrally acting antiadrenergic drug, and minoxidil, a potent antihypertensive vasodilator in 10 inpatients with refractory or accelerated hypertension or both. Clonidine in oral doses of 150 to 900 micrograms/day decreased average mean blood pressure 18.6 mm Hg (p less than 0.01), average heart rate 16.4 bpm (p less than 0.01), limb blood flow 1.63 ml/100 gm . min (p less than 0.05), and plasma renin activity 1.13 ng/ml . hr (p less than 0.025). It also increased the pre-ejection period index 12.4 msec (p less than 0.001), but did not alter the cardiac or total peripheral resistance indices. The addition of minoxidil in oral doses of 5 to 22.5 mg/day further decreased average mean blood pressure 24.2 mm Hg (p less than 0.01), preejection period index 20.6 msec (p less than 0.01), limb vascular resistance 13.2 mm Hg/min . 100 gm/ml (p less than 0.05), and total peripheral resistance 13.3 mm Hg/min . m2/l (p less than 0.01), pre-ejection period index 20.6 msec (p less than 0.01), limb vascular resistance 13.2 mm Hg/min . 100 gm/ml (p less than 0.05), and total peripheral resistance 13.3 mm Hg/min . m2/l concluded that clonidine can be used as an alternative to beta-adrenergic blockers to counteract the increased sympathetic nervous activity minoxidil induces.

Effect of minoxidil on sympathetic nervous activity in clonidine-treated hypertensive patients

The effects of clonidine and minoxidil on sympathetic nervous activity has been studied in 10 patients with accelerated or resistant hypertension. Clonidine 150 to 900 micrograms/day caused a significant decrease in blood pressure of 18.6 mm Hg, of heart rate 16.4 beats/min, of plasma renin activity 1.13ng/ml h, and of urinary noradrenaline excretion 11.55 micrograms/day, and a significant lengthening of the pre-injection period of 12.4 ms. Minoxidil 5 to 22.5 micrograms/day caused a further significant decrease in blood pressure of 24.2 mm Hg, and significant increases in heart rate 8.2 beats/min, plasma renin activity 1.68 ng/ml h and of urinary noradrenaline excretion 5.0 micrograms/day, and a significant shortening of the pre-ejection period of 20.6 ms. Neither clonidine nor minoxidil altered plasma dopamine beta-hydroxylase activity or the cardiovascular responses to treadmill exercise. It is concluded that clonidine is a useful alternative agent to block a minoxidil-induced increase in sympathetic nervous activity.

Antihypertensive effect of atenolol alone or combined with chlorthalidone in patients with essential hypertension

1 The effect of atenolol, a cardioselective β-adrenoceptor acting drug, was studied alone or combined with chlorthalidone on blood pressure, heart rate, systolic time intervals, limb blood flow and limb vascular resistance. Plasma renin activity and plasma atenolol levels were also measured in the study.

2 Supine blood pressure was reduced in group A (11 patients) from 169.4 ± 5.06/111.2 ± 2.63 mmHg to 136.9 ± 2.55/90.9 ± 1.19 mmHg (P < 0.001) during the administration of atenolol alone. Concomitantly supine heart rate was decreased from 83.9 ± 4.10 beats/min to 59.7 ± 1.67 beats/min (P < 0.01) — 4th week. After the administration of atenolol over 8 weeks, supine blood pressure was 138.6 ± 1.21/94.4 ± 2.12 mmHg and supine heart rate was 59.5 ± 2.05 beats/min.

3 Supine blood pressure was reduced in group B (27 patients) from 183.6 ± 4.58/118.7 ± 2.01 mmHg (mean ± s.e. mean of systolic and diastolic blood pressure) to 171.3 ± 4.08/108.9 ± 2.26 mmHg (P < 0.01) during the administration of atenolol alone. Concomitantly supine heart rate was decreased from 84.0 ± 1.89 to 68.7 ± 1.94 (P < 0.001) beats/min. When atenolol was combined with chlorthalidone, supine blood pressure was reduced from 171.3 ± 4.08/108.9 ± 2.26 mmHg to 143.5 ± 3.68/94.8 ± 2.63 mmHg (P < 0.001). Heart rate did not alter significantly with the addition of chlorthalidone.

4 After the administration of atenolol alone in 12 patients of group B, there was a decrease of mean blood pressure from 131.8 ± 2.88 (mean ± s.e. mean) mmHg to 119.0 ± 4.05 mmHg (P < 0.001); of heart rate from 76.4 ± 3.58 beats/min to 57.0 ± 2.55 beats/min (P < 0.001); of calf blood flow from 9.23 ± 1.39 ml 100 g^-1 min^-1 to 5.05 ± 0.89 ml 100 g^-1 min^-1 (P < 0.001); and an increase of calf vascular resistance from 16.54 ± 1.90 (mmHg min^-1 100 g^-1)/ml to 28.53 ± 3.40 (mmHg min^-1 100 g^-1)/ml (P < 0.005). Atenolol did not alter significantly pre-ejection period index (P < 0.1). In atenolol-treated patients upon addition of chlorthalidone, there was a further decrease of mean blood pressure from 119.0 ± 4.05 mmHg to 105.9 ± 4.12 mmHg (P < 0.001). There were no further significant alterations of heart rate, pre-ejection period index, calf blood flow, and calf vascular resistance (P> 0.01).

5 Atenolol decreased plasma renin activity from 4.69 ± 0.87 to 2.85 ± 0.68 ng ml^-1 h^-1 (P < 0.05), and chlorthalidone increased it from 2.85 ± 0.68 to 3.81 ± 0.98 ng ml^-1 h^-1 (P < 0.05). Plasma renin activity on atenolol plus chlorthalidone was not significantly different from that on placebo (P> 0.1).

6 There was a 7.8 fold-interindividual variability in the relationship between plasma atenolol concentrations and the atenolol dose upon administration of a single oral dose of 100 mg.

Mechanism of the haemodynamic interaction between atenolol, a cardioselective beta-adrenoreceptor-blocking agent, and chlorthalidone in hypertensive patients

1. The effect of the cardioselective β-adrenoreceptor antagonist atenolol on blood pressure, heart rate, systolic time interval, limb blood flow and limb vascular resistance was studied, both when the drug was used by itself, and also when combined with chlorthalidone. Plasma renin activity and plasma atenolol concentration were also measured.

2. After the administration of atenolol alone, there was a decrease in mean blood pressure from 131·8 ± sem 2·88 mmHg to 119·0 ± 4·05 mmHg (P &lt; 0·001), in heart rate from 76·4 ± 3·58 beats/min to 57·0 ± 2·55 beats/min (P &lt; 0·001), in calf blood flow from 9·23 ± 1·39 ml min−1100 g−1 to 5·05 ± 0·89 ml min−1 100 g−1 (P &lt; 0·001), and an increase in calf vascular resistance from 16·54 ± 1·90 (mmHg min−1100 g−1)/ml to 28·53 ± 3·40 (mmHg min−1 100 g−1)/ml) (P &lt; 0·005). Atenolol did not alter the pre-ejection period index significantly (P &gt; 0·1). In atenolol-treated patients, upon addition of chlorthalidone there was a further decrease in mean blood pressure from 119·0 ± 4·05 mmHg to 105·9 ± 4·12 mmHg (P &lt; 0·001). There was no further significant alteration in heart rate, pre-ejection period index, calf blood flow or calf vascular resistance.

3. Atenolol decreased plasma renin activity from 4·69 ± 0·87 to 2·85 ± 0·68 ng h−1 ml−1 (P &lt; 0·05), and the addition of chlorthalidone increased it from 2·85 ± 0·68 to 3·81 ± 0·98 ng h−1 ml−1 (P &lt; 0·05).

4. There was a 7·8 fold-interindividual variability in the relationship between plasma atenolol concentration and the dose of atenolol after a single oral dose of 100 mg of the drug.