[show abstract][hide abstract] ABSTRACT: Restenosis after angioplasty remains a serious complication in clinical cardiology. This study aims to investigate the stealth colloidal systems for local intra-arterial drug delivery. Micelles from polyethylene glycol conjugated with phosphatidylethanolamine and PEGylated liposomes loaded with sirolimus were prepared and characterized with regard to their loading efficiency, particle size distribution, zeta potential, morphology, nuclear magnetic resonance spectroscopy, drug release profile and stability. The antirestenotic effects of the sirolimus-loaded micelles (14nm) and liposomes (90nm) were evaluated and compared in the rat carotid injury model following local intravascular delivery. In comparison to control groups, treatment of balloon injured rats with drug loaded micelles and nanoliposomes significantly reduced vascular stenosis by 42% and 19%, respectively (P<0.05). In addition, the luminal area was significantly enlarged by 39% and 60% following treatment with sirolimus-loaded liposomes and micelles, respectively (P<0.05). Immunohistochemistry revealed that sirolimus-loaded nanocarriers suppressed cell proliferation (Ki67-positive cells) as compared to control groups without affecting the density of smooth muscle actin staining. These results suggest that both colloidal nanocarriers could serve as effective intramural drug delivery systems for the treatment of restenosis; however, phospholipid based micelles provided better antirestenotic effects than PEGylated liposomes.
International journal of pharmaceutics 07/2013; · 2.96 Impact Factor
[show abstract][hide abstract] ABSTRACT: Possible myocardial damage caused by defibrillation threshold (DFT) control and its extent after insertion of implantable cardioverter/defibrillators (ICD) is still a matter for debate. This study aimed to identify the effect of DFT checking during ICD implantation, compared with permanent pacemaker (PPM) implantation, on the magnitude of myocardial damage as assessed by cardiac troponin-T (cTNT) and CK-MB.
A total of 133 candidates for ICD implantation were enrolled in the ICD group (mean age 60.66 +/- 12.25 years; males 111 [83.5%]) as well as 130 candidates in the PPM group (mean age 69.56 +/- 12.86 years; males 64 [49.2%]). DFT was controlled in all of the ICD patients. Serum levels of cTNT and CK-MB were measured at baseline plus 8 and 24 hours following the procedure. The results were adjusted for age, gender, and other confounding factors. The amount of cTNT rise after 8 and 24 hours in the ICD group was significantly higher than in the PPM group (p < 0.001 for both). These differences remained significant after adjustment for confounding factors. The level of CK-MB rise after 8 and 24 hours was also significantly higher in the ICD group, although it lost its significance after adjustment for age, gender and other confounding variables. There was no significant relationship between the amount of energy delivered and enzyme elevation.
Elevation of cTNT and CK-MB after the ICD implantation was significantly higher than that after the PPM implantation and may be attributed to the DFT testing shock and resulting myocardial injury.
[show abstract][hide abstract] ABSTRACT: Diabetes has been shown to be independent predictor of restenosis after percutaneous coronary intervention (PCI). The aim of the present study was to investigate whether a pre- and post-procedural glycaemic control in diabetic patients was related to major advance cardiovascular events (MACE) during follow up.
We evaluated 2884 consecutive patients including 2181 non-diabetic patients and 703 diabetics who underwent coronary stenting. Diabetes mellitus was defined as the fasting blood sugar concentration ≥ 126 mg/dL, or the use of an oral hypoglycemic agent or insulin at the time of admission. Diabetic patients were categorized into two groups based on their mean HbA1c levels for three measurements (at 0, 1, and 6 months following procedure): 291 (41.4%) diabetics with good glycaemic control (HbA1c ≤ 7%) and 412 (58.6%) diabetics with poor glycaemic control (HbA1c > 7%).
The adjusted risk of MACE in diabetic patients with poor glycaemic control (HbA1c > 7%) was 2.1 times of the risk in non-diabetics (adjusted HR = 2.1, 95% CI: 1.10 to 3.95, p = 0.02). However, the risk of MACE in diabetics with good glycaemic control (HbA1c ≤ 7%) was not significantly different from that of non-diabetics (adjusted HR = 1.33, 95% CI: 0.38 to 4.68, p = 0.66).
Our data suggest that there is an association between good glycaemic control to obtain HbA1c levels ≤7% (both pre-procedural glycaemic control and post-procedural) with a better clinical outcome after PCI.
[show abstract][hide abstract] ABSTRACT: Background: The use of cardiac surgical database is necessary for evaluating and improving the quality of care. The aim of this report was to provide useful information for surgeons in Iran and other countries for their daily practice. Methods: We analyzed data from 14288 consecutive patients in four different types of procedures, namely isolated coro-nary artery bypass grafting (CABG), combined CABG and valve (CABG-V), only valve (V), and other adult cardiac surgical operations from 2002 to 2006. Results: The activity load increased from 1765 in 2002 to 3309 surgical operations in 2006 with almost 87.2% of activity being isolated CABG. The mortality rate for CABG was 1%, which decreased from 1.7% to 0.9% over the five years. The mortality rates for CABG-V and V were 5.8% and 4.8% in the last year of the study, respectively. Over the 5 yr period, the proportion of urgent operations increased substantially from 4% to 24.5% (P< 0.0001), causing a reduction in elective op-erations. The mean length of hospital stay for the entire population was 8.38±5.74 d, which remained almost steady during the study period. Conclusion: This database can serve as a valuable resource of preoperative measurers and surgical outcomes for surgeons and researchers with a view to improving overall surgical performance.
[show abstract][hide abstract] ABSTRACT: Recent studies have suggested that statins reduce the incidence of atrial fibrillation (AF) after cardiac operations. Statin therapy at intensive doses, however, has yet to be thoroughly investigated.
We retrospectively studied 1,839 consecutive patients (1,177 men [73.2%]) who underwent isolated coronary artery bypass grafting and had no history of previous AF, pacemaker implantation, or antiarrhythmic medication. Data recorded included the atorvastatin dose during hospitalization, demographic, echocardiographic, and angiographic data, medical history, drug treatment, and procedural characteristics. Continuous telemonitoring during the first 72 postoperative hours assessed for AF, which was defined as episodes lasting more than 5 minutes. The dose-related effect of atorvastatin on postoperative AF was investigated by logistic analysis in 1,607 patients: 75 (4.7%) did not receive atorvastatin vs 1,047 (65.1%) and 485 (30.2%) who received 40 mg/d or 80 mg/d, respectively, for at least 3 days before the operation.
The study population was a mean age of 60.6 ± 9.5 years. Multivariate logistic regression demonstrated that a lack of atorvastatin pretreatment along with older age, enlarged left atrium, and male sex, and not taking β-blockers, tended to be associated with an increased risk of postoperative AF. There was no significant difference between the effect of a higher (80 mg/d) and a lower dose (40 mg/d) in reducing postoperative AF.
Atorvastatin pretreatment significantly reduced the occurrence of AF after bypass grafting; nonetheless, the difference between the beneficial effects of intensive and routine atorvastatin treatments on postoperative AF was not significant.
The Annals of thoracic surgery 03/2012; 94(1):8-14. · 3.74 Impact Factor
[show abstract][hide abstract] ABSTRACT: Background: Differences in the quantity and distribution of coronary veins between patients with ischemic and non-ischemic cardiomyopathy might affect the potential for the left ventricular (LV) lead targeting in patients undergoing cardiac resynchronization therapy (CRT). In the current study, we assessed and compared the suitability of the coronary venous system for the LV lead placement in ischemic and dilated cardiomyopathy.
Methods: This single-centre study, performed at our hospital, retrospectively studied 173 patients with the New York Heart Association class III or IV who underwent CRT. The study population was comprised of 74 patients with an ischemic underlying etiology and 99 patients with a non-ischemic etiology. The distribution of the veins as well as the final lead positions was recorded.
Results: There was no significant difference between the two groups in terms of the position of the available suitable vein with the exception of the posterior position, where the ischemic group had slightly more suitable veins than did the dilated group. There was also no significant difference with respect to the final vein, through which the LV lead was inserted. Comparative analysis showed that the patients with previous coronary artery bypass grafting surgery (CABG) had significantly fewer suitable veins in the posterolateral position than did the non-CABG group. There was, however, no significant difference between the two subgroups regarding the final vein position in which the leads were inserted.
Conclusion: The final coronary vein position suitable and selected for the LV lead insertion was not different between the cases with cardiomyopathy with different etiologies, and nor was it different between the ischemic cases with and without a history of CABG. Patients with a history of procedures around the coronary vessel may have an intact or recovered venous system and may, therefore, benefit from transvenous LV lead placement for CRT.
Journal of Tehran University Heart Center. 01/2012; 7(1).
[show abstract][hide abstract] ABSTRACT: Differences in the quantity and distribution of coronary veins between patients with ischemic and nonischemic cardiomyopathy might affect the potential for the left ventricular (LV) lead targeting in patients undergoing cardiac resynchronization therapy (CRT). In the current study, we assessed and compared the suitability of the coronary venous system for the LV lead placement in ischemic and dilated cardiomyopathy.
This single-centre study, performed at our hospital, retrospectively studied 173 patients with the New York Heart Association class III or IV who underwent CRT. The study population was comprised of 74 patients with an ischemic underlying etiology and 99 patients with a non-ischemic etiology. The distribution of the veins as well as the final lead positions was recorded.
There was no significant difference between the two groups in terms of the position of the available suitable vein with the exception of the posterior position, where the ischemic group had slightly more suitable veins than did the dilated group (48.4% versus 32.1%, p value = 0.049). There was also no significant difference with respect to the final vein, through which the LV lead was inserted. Comparative analysis showed that the patients with previous coronary artery bypass grafting surgery (CABG) had significantly fewer suitable veins in the posterolateral position than did the non-CABG group (16.3% versus 38.7%, p value = 0.029). There was, however, no significant difference between the two subgroups regarding the final vein position in which the leads were inserted.
The final coronary vein position suitable and selected for the LV lead insertion was not different between the cases with cardiomyopathy with different etiologies, and nor was it different between the ischemic cases with and without a history of CABG. Patients with a history of procedures around the coronary vessel may have an intact or recovered venous system and may, therefore, benefit from transvenous LV lead placement for CRT.
Journal of Tehran University Heart Center 01/2012; 7(1):10-4.
[show abstract][hide abstract] ABSTRACT: Cardiac autonomic neuropathy (CAN) is a critical complication of type 2 diabetes mellitus (T2DM). Heart rate variability (HRV) is a noninvasive tool to assess cardiac autonomic function. We aimed to evaluate whether CAN is associated with increased risk of atherosclerosis in T2DM. A total of 57 diabetic and 54 nondiabetic subjects, free of coronary heart disease, were recruited. Carotid intima media thickness (CIMT), coronary calcium score (CAC), and brachial Flow Mediated Dilation (FMD) were measured. Heart rate variability and vagal components of autonomic function were determined. Significant reduction of normalized HF power (P < 0.05) and total power (P < 0.01) was observed in T2DM. CIMT and CAC scores were significantly higher while FMD was significantly lower in diabetics (P < 0.01 for all). Median HbA(1c) levels were significantly higher in diabetics. CIMT was inversely and independently associated with total power both in diabetics and controls (P < 0.01 for both groups). There was also an inverse association between total power and median HbA(1c). Autonomic dysfunction, especially parasympathetic neuropathy, was present since early-stage T2DM. This was related to subclinical atherosclerosis. Early detection of cardiac autonomic neuropathy can help us detect the development of atherosclerosis earlier in T2DM to prevent unfavorable outcomes.
[show abstract][hide abstract] ABSTRACT: This study was directed towards the preparation and optimization of PEGylated (PEG, poly(ethylene glycol)) estradiol benzoate (ESB)-loaded liposomes to be used for the treatment of restenosis by local vascular delivery. Various liposomal formulations were prepared by thin film hydration method followed by sonication. Response surface methodology was applied to study the influence of three different independent variables, on the response of entrapment efficiency (%EE). Liposomes were characterized in terms of size, zeta potential, %EE and release profile. Incorporation of ESB was higher in egg phosphatidylcholine (EPC) liposomes, whereas the drug was displaced from liposomes, as the cholesterol (Chol) content of liposome increased. The optimum formulation composed of EPC/dioleyloxy trimethylammonium propane/distearoylphosphatidylethanolamine-PEG2000 with a molar proportion of 8.5:1:0.5 had the highest EE. In vivo studies in the balloon-injured rat carotid arteries revealed the potential of ESB-loaded liposomes as efficient local and controlled drug delivery systems to reduce restenosis.
Journal of Microencapsulation 11/2011; 29(1):83-94. · 1.57 Impact Factor
[show abstract][hide abstract] ABSTRACT: BACKGROUND: In order to benefit from a coronary artery bypass graft (CABG) surgery, patients must adhere to medical recommendations and health advices. Despite the importance of adherence in CABG patients, adherence rates are disappointingly low. Despite the low adherence rates, very few articles regarding adherence-enhancing intervention among heart patients have been published. PURPOSE: The goal of this study was to assess the effects of the Information-Motivation-Behavioral Skills (IMB) model-based intervention on the IMB model constructs among patients undergoing CABG and to evaluate the relationship of information, motivation, and behavioral skills with adherence. METHOD: A total of 152 CABG patients were randomly assigned to either an intervention group or to a standard care control group. Participants completed pretest measures and were reassessed 1 month later. RESULTS: Findings showed mixed support for the effectiveness of the intervention. There was a significant effect of IMB intervention on information and motivation of patients, but no significant effect on behavioral skills. Furthermore, the results revealed that intervention constructs (information, motivation, and behavioral skills) were significantly related to patients' adherence. CONCLUSIONS: Findings provided initial evidence for the effectiveness of IMB-based interventions on the IMB constructs and supported the importance of these constructs to improve adherence; however, there are additional factors that need to be identified in order to improve behavioral skills more effectively.
International Journal of Behavioral Medicine 09/2011; · 2.63 Impact Factor
[show abstract][hide abstract] ABSTRACT: The main objective of this study was to formulate an effective controlled-release liposomal drug delivery system for sirolimus (SIR), a potent antiproliferative and anti-inflammatory drug, to be used for the treatment of restenosis following local vascular delivery. Liposomes were prepared using remote film loading method and characterized with regard to entrapment efficiency (EE), size distribution and zeta potential. The effects of key formulation and proceeding variables on both EE and drug release were studied using a fractional factorial design. By means of this entrapment technique, 98% SIR incorporation was achieved. Nanoliposomes were found to have average size of 110 nm and zeta potential of -9 mV. Developed formulations were found to have prolonged drug release for up to 3 weeks in vitro; this was best fitted by the Higuchi model. Other scopes of this work were to determine the applicability of sirolimus-loaded nanoliposomes (SIR-L) as drug carriers for the treatment of restenosis and to evaluate the effect of the presence of rigid lipids on the in vivo efficacy of the liposomal carrier of SIR. In vivo studies in balloon injured rat carotid arteries revealed the potential of SIR-loaded liposomes as efficient local and controlled drug delivery systems to reduce restenosis.
International journal of pharmaceutics 04/2011; 414(1-2):16-27. · 2.96 Impact Factor
[show abstract][hide abstract] ABSTRACT: Pathophysiological mechanisms and pathways linking cardiovascular mortality and morbidity with air pollution were recently hypothesized. The present study evaluated association between air pollution and changes in heart rate variability as a marker of cardiac autonomic function in healthy individuals, and also determined the frequency of cardiac arrhythmias and QT interval changes on polluted compared to unpolluted days.
Continuous Holter electrocardiography (ECG) monitoring was conducted on 21 young healthy individuals in the two episodes of clean air and elevated air pollution in Tehran. All subjects underwent a medical history review, a physical examination and echocardiography in order to rule out structural heart diseases. Measured pollutants and parameters included NO(2), CO(2), O(3), SO(2), and PM10, which all showed significantly higher concentrations on polluted days. Holter parameters were measured for 24-h time segments and compared.
Maximum heart rate was significantly lower in polluted air conditions in comparison with clean air conditions (115.1 ± 32.2 vs. 128.9 ± 17.7), and the square root of the mean of squared differences between adjacent NN intervals (r-MSSD) was higher in polluted air compared to clean air (99.0 ± 58.2 vs. 58.5 ± 26.4). Also, the occurrence of nonsustained supraventricular tachycardia was reported in 42.9% of participants in air pollution episodes, whereas this arrhythmia was not seen in clear air conditions (p = 0.001).
Changes in air pollution indices may lead to the occurrence of nonsustained supraventricular tachycardia, a slight reduction in maximum heart rate, and an increase in r-MSSD in healthy individuals. Air quality monitoring in cities associated with a high exposure to air pollutants is recommended in order to prevent such events.
Environmental Health and Preventive Medicine 07/2010; 15(4):217-21.
[show abstract][hide abstract] ABSTRACT: This study tested the efficacy of the Information-Motivation-Behavioral (IMB) skills model-based intervention to promote adherence among patients undergoing Coronary Artery Bypass Grafting (CABG) surgery, and evaluated the relationship of psychological variables with adherence. A total of 152 CABG patients were randomly assigned to either an intervention group or to a standard care control group. Participants completed pretest measures and were reassessed one and three months later. Findings revealed that the intervention group was significantly more adherent, which showed support for the effectiveness of the IMB-based intervention. Furthermore, psychological factors played an important role in patient adherence.
Journal of Health Psychology 05/2010; 15(6):828-37. · 1.22 Impact Factor
[show abstract][hide abstract] ABSTRACT: Scorpion envenomation is a life-threatening condition, especially in children
and elderly individuals affected by respiratory and cardiovascular diseases. In this study,
the toxic effects of median lethal dose (LD50) injections of Mesobuthus eupeus (Me)
venom on the heart and lungs of anesthetized rabbits were investigated. Six rabbits were
selected and alterations in their electrocardiogram, heart rate, respiration and blood
pressure before and after venom injection were recorded. Cardiac troponin T (cTnT),
creatinine kinase muscle-brain fraction (CK-MB) and lactate dehydrogenase (LDH) were
measured at 0, 1 and 3 hours after envenomation and pathology studies were carried out
postmortem. All the animals showed signs and symptoms of envenomation within 40
minutes and died 3 to 3.5 hours after venom injection. Pathology studies revealed
alveolar edema in 100% of the rabbits and myocardial infarction in 16%. The main
histopathological changes were myocytolysis, coagulation necrosis, focal hemorrhage,
thrombus formation both in myocardium and on endocardial surfaces as well as
inflammatory infiltrates in the heart and hemorrhage, vascular thrombus and interstitial
inflammation in the lungs. ECG monitoring of rabbits showed ST elevation, ST
depression and inverted T and Q waves. In addition, although cTnT levels increased in
16% of the animals and serum LDH was also augmented, none of these changes was
statistically significant. The enzyme CK-MB also did not show any change after Me
venom injection. In conclusion, the results of this study showed that Me venom killed
animals in less than 3.5 hours through severe pulmonary damage and it appears that the
deaths could not be attributed to cardiovascular lesions. Therefore, Me venom effects on
the lungs are so important that they appear to be independent of heart damage.
Journal of Venomous Animals and Toxins including Tropical Diseases 02/2010; 16(1):46-59. · 0.55 Impact Factor
[show abstract][hide abstract] ABSTRACT: This study is aimed to evaluate the impact of air pollution on the in-hospital mortality of ischemic heart disease patients in Tehran as a polluted metropolis. A cross sectional study conducted in Tehran heart center. We compared two separate exposure levels of air pollutants in patients expired in hospital (n = 23) versus patients discharged alive (n = 1219). The first was air pollutants daily mean concentration at the date of admission and the second was air pollutants daily mean concentration at the date of admission and the three following days. Patients' demographic, clinical and paraclinical data were gathered from the hospital databank between 23 September and 21 December 2005. Meteorological data were obtained from Tehran air quality control company. In-hospital mortality rate was 1.9% for men and 1.8% for women. The expired patients were older than survived patients. The mean concentration of carbon monoxide, dust, nitrous oxide, other nitrogen compounds and sulfur dioxide were significantly higher and mean temperature was significantly lower at admission date of expired patients. In expired patients, mean concentrations of nitrous oxide, nitrogen dioxide, other nitrogen compounds, sulfur dioxide, dust and non-methane hydrocarbons were significantly higher at admission date and three following days compared to survived patients. There was significant direct relationship between air pollution level and in-hospital mortality of ischemic heart disease patients.
[show abstract][hide abstract] ABSTRACT: The use of diagnostic and therapeutic methods for assessing pulmonary vein due to its status as a main source of ectopic beats for the initiation of atrial dysrrythmias is strongly recommended. We report the case of a 13-year-old girl who was admitted to our hospital with the electrocardiogram manifestation of an ectopic atrial tachycardia. The focus of arrhythmia was inside the right upper pulmonary vein. The patient underwent successful ablation with a conventional electrophysiology catheter via the retrograde aortic approach. We showed that when the origin of atrial tachycardia is in the right upper pulmonary vein, it is possible to advance the catheter into this vein via the retrograde aortic approach and find the focus of arrhythmia. This case demonstrates that right upper pulmonary vein mapping is feasible through the retrograde aortic approach and it is also possible to ablate the arrhythmia using the same catheter and approach.
The journal of Tehran Heart Center. 01/2010; 5(3):146-9.