Search PubMed⌕ Search

Biomedical subjects

Sridhar Kamath

Publications and source records attributed to Sridhar Kamath.

11 recordsLinked to original sources
PubMed2005

Hyperdense pericardial effusion in dermatomyositis and contrast induced nephropathy.

Pericardial involvement in dermatomyositis is rare and usually asymptomatic. In many instances, a diagnosis of pericardial involvement is not found until autopsy. Renal failure associated with connective tissue disorders can result in or potentially exaggerate pericardial inflammation. We report an unusual case of high-density pericardial effusion in a patient with dermatomyositis consequent upon contrast nephropathy as demonstrated by computed tomography. High-density pericardial effusion can be a result of an insidious cause such as pericardial inflammation rather than the more usual causes such as coronary or cardiac perforation.

Acute Kidney Injury↗
PubMed2004

Platelet indexes in relation to target organ damage in high-risk hypertensive patients: a substudy of the Anglo-Scandinavian Cardiac Outcomes Trial (ASCOT).

OBJECTIVES: We sought to investigate the relationship between target organ damage (TOD) in hypertension and a prothrombotic/hypercoagulable state, using a new technique of "platelet lysis" to quantify the amount of P-selectin per platelet (pP-sel), and to correlate it with other platelet markers (e.g., mass, volume and granularity, soluble P-selectin [sP-sel], and beta-thromboglobulin [beta-TG]). BACKGROUND: The increased risk of TOD in hypertension may be related to a prothrombotic/hypercoagulable state, with abnormalities in platelets, such as increased expression of P-selectin. METHODS: We studied 199 patients (mean age 68 years, 75% men) with hypertension. Of these, 125 had TOD (e.g., stroke, previous myocardial infarction, angina, left ventricular hypertrophy). Values obtained were compared with those from 59 healthy normotensive control subjects (mean age 68 years, 58% men). RESULTS: Hypertensive patients had a higher mean platelet volume, mass, pP-sel, sP-sel, and beta-TG and lower platelet granularity (all p < 0.01), but a similar platelet count, as compared with controls. Within the hypertensive group, those with evidence of TOD had significantly larger platelets with greater mass but had lower granularity, sP-sel, and pP-sel levels than those without TOD, possibly reflecting increased aspirin use. On multivariate analysis, aspirin use was a determinant of pP-sel (p = 0.03) and sP-sel (p = 0.01), but the use of other drugs or other co-morbidity (e.g., diabetes, smoking) did not influence either P-selectin value. CONCLUSIONS: Patients with hypertension have evidence of changes in platelet physiology, as reflected by a higher level of pP-sel. Patients with TOD also had larger platelets, with greater mass, and the use of aspirin lowered pP-sel and sP-sel levels. These changes may have implications for the pathophysiology of cardiovascular and cerebrovascular disease in hypertension.

Aged↗
PubMed2002

A prospective randomized trial of aspirin-clopidogrel combination therapy and dose-adjusted warfarin on indices of thrombogenesis and platelet activation in atrial fibrillation.

OBJECTIVES: This study was designed to investigate whether or not combination aspirin-clopidogrel therapy would reduce markers of thrombogenesis and platelet activation in atrial fibrillation (AF), in a manner similar to warfarin. BACKGROUND: Dose-adjusted warfarin is beneficial as thromboprophylaxis in AF, but potentially serious side effects and regular monitoring leave room for alternative therapies. METHODS; We randomized 70 patients with nonvalvular AF who were not on any antithrombotic therapy to either dose-adjusted warfarin (international normalized ratio 2 to 3) (Group I) or combination therapy with aspirin 75 mg and clopidogrel 75 mg (Group II). Plasma indices of thrombogenesis (fibrin D-dimer, prothrombin fragment 1+2) and platelet activation (beta-thromboglobulin [TG] and soluble P-selectin) were quantified, along with platelet aggregation responses to standard agonists, at baseline (pretreatment) and at six weeks posttreatment. RESULTS; Pretreatment levels of fibrin D-dimer (p = 0.001), beta-TG (p = 0.01) and soluble P-selectin (p = 0.03) were raised in patients with AF, whereas plasma prothrombin fragment 1+2 levels and platelet aggregation were not significantly different compared with controls. Dose-adjusted warfarin reduced plasma levels of fibrin D-dimer, prothrombin fragment 1+2 and beta-thromboglobulin levels at six weeks (all p < 0.001), enhanced plasma levels of soluble P-selectin (p < 0.001) and had no significant effect on platelet aggregation. Aspirin-clopidogrel combination therapy made no difference to the plasma markers of thrombogenesis or platelet activation (all p = NS), but the platelet aggregation responses to adenosine diphosphate (p < 0.001) and epinephrine (p = 0.02) were decreased. CONCLUSIONS: Aspirin-clopidogrel combination therapy failed to reduce plasma indices of thrombogenesis and platelet activation in AF, although some aspects of ex vivo platelet aggregation were altered. Anticoagulation with warfarin may be superior to combination aspirin-clopidogrel therapy as thromboprophylaxis in AF.

Aged↗
PubMed2002

Platelet P-selectin levels in relation to plasma soluble P-selectin and beta-thromboglobulin levels in atrial fibrillation.

BACKGROUND AND PURPOSE: The increased risk of stroke and thromboembolism in atrial fibrillation (AF) may be related to a prothrombotic or hypercoagulable state, with abnormalities of hemostasis and platelet activation. To investigate the role of platelets in AF and the influence of antithrombotic therapy, we developed and then applied a new assay to detect the absolute amount of P-selectin per platelet (pP-selectin) based on cell lysis. Thus, pP-selectin in AF patients was compared with that of healthy controls and also with plasma soluble P-selectin (sP-selectin) and beta-thromboglobulin as established indices of platelet activation. METHODSMDSAH: We studied 122 patients (mean [SD] age, 71 [9] years; 65 men) with chronic AF of >6 weeks' duration: 34 were not on antithrombotic therapy, 30 were taking aspirin (75 to 300 mg/d), and 58 were fully anticoagulated with warfarin. pP-selectin was compared with sP-selectin and plasma beta-thromboglobulin levels (enzyme-linked immunosorbent assay). Results were compared with those of 23 healthy controls (mean [SD] age, 74 [9] years; 7 men) in sinus rhythm. RESULTS: pP-selectin was significantly lower in AF patients on no antithrombotic therapy (P=0.03) than in healthy controls, but sP-selectin and beta-thromboglobulin levels were not significantly different and did not differ in patients taking aspirin or warfarin. However, pP-selectin was lower in patients with AF on aspirin than in those on warfarin (P<0.05). pP-selectin/sP-selectin correlated significantly in healthy controls (r=0.47, P=0.03) but inversely (r=-0.43, P=0.03) in AF patients on no antithrombotic therapy. CONCLUSIONS: Lower levels of pP-selectin may represent a depletion of pP-selectin after platelet activation in AF. Aspirin further decreases pP-selectin levels compared with warfarin. On the basis of the principle of platelet lysis, we demonstrate that it is possible to determine the amount of P-selectin per platelet, which may be regulated in the megakaryocyte through a cyclooxygenase-dependent pathway.

Aged↗
PubMed2002

Ethnic differences in patient perceptions of atrial fibrillation and anticoagulation therapy: the West Birmingham Atrial Fibrillation Project.

BACKGROUND AND PURPOSE: We hypothesized that different ethnic groups would have different levels of knowledge and perceptions of atrial fibrillation (AF) and of their antithrombotic therapy. To investigate this further, we conducted a cross-sectional survey of patients with documented chronic AF who were attending the anticoagulation clinic in our city center teaching hospital, serving a multiethnic population. METHODS: We surveyed 119 patients (77 male; mean age 69+/-9 years [mean+/-SD]); of these, 39 were Indo-Asian (33%), 27 Afro-Caribbean (23%), and 53 white (44%). RESULTS: Only 63% of patients in the overall study cohort were aware of their cardiac condition, with Indo-Asians and Afro-Caribbeans significantly less aware of AF compared with the white patients (P<0.001). When questioned about the perception of the severity of the underlying condition, the majority (61%) felt that AF was "not serious." A large proportion were unaware that AF predisposed to thrombosis and stroke; among the ethnic groups, Indo-Asians appeared to be the least aware of the stroke and thromboembolic associations of AF. Only 52% in the whole cohort were aware of the reason(s) for commencing their warfarin, whereas the remainder began warfarin therapy simply because their "doctor told them to." Most patients in the whole cohort were aware of warfarin being used to prevent blood clots (65%) or stroke (66%), but Indo-Asians and Afro-Caribbeans were less so. Only 45% of the study cohort believed that there was some risk associated with warfarin therapy in the form of either "bleeding" or "poisoning." Only a minority of Indo-Asians and Afro-Caribbeans with AF felt that their doctor had given them enough information about their warfarin therapy, and many from these ethnic groups felt that they were careless about taking their warfarin. CONCLUSIONS: In conclusion, many patients with AF possess very limited knowledge of AF as well as its consequences and therapy. In particular, our study has highlighted significant differences between different ethnic groups in terms of their knowledge of the risks, actions, and benefits of warfarin as well as of AF itself.

Aged↗
PubMedDate not supplied

Pseudoaneurysm of the internal mammary artery as an unusual cause of post-sternotomy hemorrhage: the role of multislice computed tomography in the diagnosis and treatment planning.

Pseudoaneurysm of the internal mammary artery (IMA) following median sternotomy is extremely rare. To date, the reported cases are only in single figures. The majority of these pseudoaneurysms were suspected from the clinical presentation, echocardiography or computed tomography (CT) but were only confirmed on contrast angiography. This case report demonstrates the current ability to carry out detailed vascular imaging on a 16-slice CT scanner. This accurate delineation of the pseudoaneurysm allowed targeted therapeutic embolization to be performed without unnecessary angiographic imaging.

Aneurysm, False↗