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Background & objectives: Vaccination and natural infection can both augment the immune responses against severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), but how omicron infection has affected the vaccine-induced and hybrid immunity is not well studied in Indian population. The present study was aimed to assess the durability and change in responses of humoral immunity with age, prior natural infection, vaccine type and duration with a minimum gap of six months post-two doses with either ChAdOx1 nCov-19 or BBV152 prior- and post-emergence of the omicron variant. Methods: A total of 1300 participants were included in this observational study between November 2021 and May 2022. Participants had completed at least six months after vaccination (2 doses) with either ChAdOx1 nCoV-19 or an inactivated whole virus vaccine BBV152. They were grouped according to their age (? or ?60 yr) and prior exposure of SARS-CoV-2 infection. Five hundred and sixteen of these participants were followed up after emergence of the Omicron variant. The main outcome was durability and augmentation of the humoral immune response as determined by anti-receptor-binding domain (RBD) immunoglobulin G (IgG) concentrations, anti-nucleocapsid antibodies and anti-omicron RBD antibodies. Live virus neutralization assay was conducted for neutralizing antibodies against four variants – ancestral, delta and omicron and omicron sublineage BA.5. Results: Before the omicron surge, serum anti-RBD IgG antibodies were detected in 87 per cent participants after a median gap of eight months from the second vaccine dose, with a median titre of 114 [interquartile range (IQR) 32, 302] BAU/ml. The levels increased to 594 (252, 1230) BAU/ml post- omicron surge (P<0.001) with 97 per cent participants having detectable antibodies, although only 40 had symptomatic infection during the omicron surge irrespective of vaccine type and previous history of infection. Those with prior natural infection and vaccination had higher anti-RBD IgG titre at baseline, which increased further [352 (IQR 131, 869) to 816 (IQR 383, 2001) BAU/ml] (P<0.001). The antibody levels remained elevated after a mean time gap of 10 months, although there was a decline of 41 per cent. The geometric mean titre was 452.54, 172.80, 83.1 and 76.99 against the ancestral, delta, omicron and omicron BA.5 variants in the live virus neutralization assay. Interpretation & conclusions: Anti-RBD IgG antibodies were detected in 85 per cent of participants after a median gap of eight months following the second vaccine dose. Omicron infection probably resulted in a substantial proportion of asymptomatic infection in the first four months in our study population and boosted the vaccine-induced humoral immune response, which declined but still remained durable over 10 months
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Normal pregnancy is associated with intense alterations in the maternal cardiovascular system. The aim of the present study was, to assess the influence of normal pregnancy on maternal central aortic pressures, arterial stiffness, and arterial wave reflection using non-invasive PC based cardiovascular risk analysis system (PeriscopeTM). The current study was conducted on 137 women with, normotensive, healthy, singleton pregnancies at first trimester (n=42), second trimester (n=48), third trimester (n=47) of pregnancy and 35 age matched non-pregnant controls. There was no significant correlation between the estimated means for age and systolic and diastolic blood pressure. There was progressive and significant increase in BMI as pregnancy progresses (p=0.0001). Heart rate rose significantly from Pre-pregnant to second and second to third trimesters (P<0.003). There were no significant changes observed in central aortic diastolic pressure (AoDiaBP) as pregnancy progressed (p=0.235) however Post Hoc comparisons showed a significant increase in central aortic systolic blood pressure (AoSysBP) and central aortic pulse pressure (AoPP) during first trimester when compared with non pregnant control group (p=0.039 and 0.048 respectively). There was significant increase in central aortic augmentation pressure (AoAugP) in first trimester compared to non pregnant control group (p=0.024). All the parameters of central aortic pressures were increased in the first trimester but decreased in the second trimester and again increased in the third trimester of pregnancy. There was a significant drop in Brachial-Ankle Pulse wave Velocity (baPWV) during first trimester of pregnancy compared to non-pregnant control group (p=0.0001) after that there is a progressive increase in baPWV in second and third trimester of pregnancy. In the third trimester baPWV is increased to more than non-pregnant control group but it was non significant (p=0.562) however it was significantly higher than first trimester (p=0.0001). Carotid-femoral Pulse wave velocity (cfPWV) also followed the same sequence as BaPWV but the drop in cfPWV during first trimester was not significant (P=0.135). All of the variables of hemodynamic and arterial compliance differed between participants with various trimester of pregnancy and non-pregnant control group. A significant up and down changes in Augmentation index (Aix) was observed from control to first, second and third trimester of pregnancy (3.14 to 6.74 to 2.63 to 10.51 respectively, P<0.0001). To summarize our report show that normal pregnancy is associated with a significant cardiovascular adaptation indicated by alteration in central aortic blood pressure, augmentation index and pulse wave velocity.
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Obesity is associated with increased cardiovascular morbidity and mortality. A direct effect of isolated obesity on cardiac function is not well established. The study was designed to determine the direct effect of various grades of isolated obesity on Echocardiographic indices of systolic and diastolic left ventricular function. Forty five overweight & obese and 30 normal weight, serving personnel without any other pathological condition were studied. Group I (n=23) consisted of subjects with normal weight and body mass index (BMI 18.5-22.9 kg/m2), Group II (n=28) of overweight subjects (BMI 23-24.9 kg/m2) and Group III (n=24) of obese subjects (BMI ≥25 kg/m2). Echocardiographic indices of systolic and diastolic function were obtained and dysfunction was assumed when at least two values differed by ≥2 SD from the normal weight group. Ejection fraction was increased (p=0.001) in group II and III however fractional shortening was increased significantly in group III (<0.001). Left ventricular dimensions (EDD & ESD) were increased (P<0.001, 0.002) but relative wall thickness was unchanged in group II & III. Systolic dysfunction was not observed in any of the obese patients. The deceleration time was increased (P<0.01) in overweight and obese subjects compared to normal group individuals. No difference was found between obesity subgroups. Subclinical diastolic dysfunction in the form of reduced E/A ratio and increased deceleration time was more prevalent among obese subjects. BMI correlated significantly with indices of left ventricular systolic and diastolic function. Subclinical left ventricular diastolic dysfunction was noted in all grades of obesity which correlates with BMI.
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Prevalence, determinants, and prognostic value of left ventricular function in subjects with asymptomatic essential hypertension are still incompletely known. The goal of this study was to investigate the effects of asymptomatic untreated essential hypertension on left ventricular structure and function. The left ventricular functions were assessed among 127 hypertensive and 80 healthy subjects. American society of echocardiography (ASE) convention was applied to measure the stroke volume, percentage ejection fraction, percentage fractional fiber shortening, cardiac output and cardiac index. The stroke volume, cardiac output and cardiac index were normal but significantly high among hypertensive compared to normotensive subjects (P<0.05). The percentage ejection fraction and fractional fiber shortening were significantly reduced among hypertensives compared to normotensives (P<0.05). The significant impairment of percentage fractional fiber shortening is due to alteration in dimension of left ventricular wall thickness, left ventricular cavity and left ventricular geometry. This carries prognostic implication and requires further documentations, investigations and researches. Percentage ejection fraction and fractional fiber shortening is considered a hallmark of normal left ventricular function. The left ventricular contractile state was negatively correlated to left ventricular after load parameters. So the main objective of management of hypertensive subjects should be, to reduce the after load to improve the left ventricular contractile state.
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Cardiac arrhythmias as cause of sudden cardiac death remains an important public health problem. The availability of effective treatment in terms of the implantable defibrillator makes it critical to identify individuals at risk. An essential step in this process is the use of noninvasive techniques to screen patients and identify those at risk. The detection of ventricular late potential using the SAECG as a non-invasive technique is being explored for this purpose. The objective of the study was to stratify the future cardiovascular events including life threatening cardiac arrhythmias, in different cardiac diseases through positive and negative predictive values of SAECG and comparing with EF% another mechanical determinant. The study was conducted on 152 subjects selected from the OPD and admitted case of the New Civil Hospital and Govt. Medical College, Surat; between 25 to 75 years of age group, from August 2001 to June 2004. 80 healthy subjects free from any major acute/chronic illness were selected as a control using our own normative values for SAECG. The statistical analysis was performed using SPSS package. The results obtained were analyzed for significance by using Chi square and Independent ‘t’ test. When we compared the cardiac arrhythmic events on 6 month follow-up study, based on SAECG and EF% separately we found that negative predictive value of SAECG was more (99.1%) than negative predictive value of EF% (93.6%). However positive predictive values for cardiac arrhythmic events of SAECG were less (28.9%) compare to EF% (42.9%).When both the parameters SAECG and EF% are considered together the negative as well as positive predictive values of these tests were quite high (100% and 50% respectively). In this study conducted on 152 patients we found that SAECG and EF% together were an accurate predictor of the cardiac arrhythmic events in terms of positive and negative predictive value while SAECG or EF% alone were not. However SAECG has got a more negative predictive value compare to EF%. In this study SAECG compared favorably or even better than EF% for risk stratification. SAECG and EF% together (and not separately) may be considered as a better investigational tool to stratify future cardiovascular arrhythmic events.