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Biomedical subjects

D S Gambhir

Publications and source records attributed to D S Gambhir.

At least 19 recordsLinked to original sources
PubMed2001

Evaluation of Lp[a] and other independent risk factors for CHD in Asian Indians and their USA counterparts.

Conventional risk factors for coronary heart disease (CHD) do not completely account for the observed increase in premature CHD in people from the Indian subcontinent or for Asian Indians who have immigrated to the USA. The objective of this study was to determine the effect of immigration to the USA on plasma levels of lipoprotein [a] (Lp[a]) and other independent risk factors for CHD in Asian Indians. Three subject groups were studied: group 1, 57 subjects living in India and diagnosed with CHD (CHD patients); group 2, 46 subjects living in India and showing no symptoms of CHD (control subjects); group 3, 206 Asian Indians living in the USA. Fasting blood samples were drawn to determine plasma levels of triglyceride (TG), total cholesterol (TC), low density lipoprotein [LDL cholesterol (LDL-Chol)], high density lipoprotein [HDL cholesterol (HDL-Chol)], apolipoprotein B-100 (apoB-100), and Lp[a]. Apolipoprotein [a] (apo[a]) size polymorphism was determined by immunoblotting. Plasma TG, apoB-100, and Lp[a] concentrations were higher in CHD patients than in control and USA groups. CHD patients had higher levels of TC and LDL-Chol and lower HDL-Chol than control subjects. However, the USA population had higher levels of TC, LDL-Chol, and apoB-100 and lower HDL-Chol than control subjects. Plasma Lp[a] levels were inversely correlated with the relative molecular weight of the more abundant of each subject's two apo[a] isoforms (MAI), and CHD patients showed higher frequencies of lower relative molecular weights among MAI. Our observed changes in lipid profiles suggest that immigrating to the USA may place Asian Indians at increased risk for CHD. This study suggests that elevated plasma Lp[a] confers genetic predisposition to CHD in Asian Indians, and nutritional and environmental factors further increase the risk of CHD. This is the first report implicating MAI size as a predictor for development of premature CHD in Asian Indians. Including plasma Lp[a] concentration and apo[a] phenotype in screening procedures may permit early detection and preventive treatment of CHD in this population.

Adult↗
PubMed1992

Balloon angioplasty of native coarctation of the aorta in adolescents and young adults.

Balloon angioplasty of native coarctation of the aorta was performed in 35 consecutive adolescents and young adults, aged 14 to 37 years (mean 22.6 +/- 7.1). Twenty-eight (80%) patients had isolated discrete coarctation, six (17.1%) had tubular hypoplasia of the aortic isthmus, and one (2.9%) had hypoplasia of the post-coarctation aorta. The peak systolic pressure gradient decreased from 78.5 +/- 23.9 to 15.7 +/- 11.6 mm Hg (p less than 0.001), and the mean coarctation diameter increased from 4.7 +/- 2.4 to 13.1 +/- 2.7 mm (p less than 0.001) immediately after angioplasty. Patients with discrete-type coarctation had significantly less residual gradient than patients with long-segment tubular coarctation (12.3 +/- 10.7 vs 27.2 +/- 6.6 mm Hg, p less than 0.01). On recatheterization and angiography in 26 patients at 12.6 +/- 1.5 months after dilatation, there was no significant change in gradient (15.5 +/- 13.3 mm Hg) and diameter (13.1 +/- 1.8 mm) from the immediate post-angioplasty results. However, two patients had an increase in gradient and three had small aortic aneurysms with no change in appearance on restudy after 2 years. After 3 to 67 months' (mean 32.7 +/- 19.2) follow-up, all patients showed continued clinical improvement. Hypertension was relieved in 37.5% (12/32) and improved in 59.4% (19/32). Our experience suggests that balloon angioplasty of native aortic coarctation in adolescents and young adults is safe and highly effective with sustained improvement on intermediate-term follow-up.

Adolescent↗
PubMed1987

Percutaneous transluminal balloon angioplasty of the aorta in patients with aortitis.

Four patients with aortitis and stenotic lesions of the aorta were successfully treated by percutaneous transluminal balloon angioplasty. The peak systolic gradient across the constrictions decreased from 82.5 +/- 35.7 to 37.5 +/- 18.5 mm Hg immediately after dilatation. Repeat angiography in the first three patients performed 2 months later showed a further decrease in the gradient to 13.8 +/- 9.5 mm Hg. There were no complications during or after the procedure, and all the patients have shown remarkable symptomatic relief during the follow-up.

Adolescent↗
PubMedDate not supplied

Early and long-term results of subclavian angioplasty in aortoarteritis (Takayasu disease): comparison with atherosclerosis.

PURPOSE: To compare the early and long-term outcomes of subclavian artery angioplasty in patients with aortoarteritis and atherosclerosis. METHODS: Sixty-one subclavian artery angioplasties were performed in 55 consecutive patients with aortoarteritis (n = 32) and atherosclerosis (n = 23) between 1986 and 1995. An arch aortogram followed by a selective subclavian artery angiogram was done to profile the site and extent of the lesion, its relation to the vertebral artery, and the distal circulation. Percutaneous transluminal angioplasty (PTA) was performed via the femoral route for 56 stenotic lesions and 5 total occlusions. RESULTS: PTA was successful in 52 (92.8%) stenotic lesions and 3 (60%) total occlusions. Three patients (5.4%) had complications, that could be effectively managed nonsurgically. Compared with atherosclerosis, patients with aortoarteritis were younger (27.4 +/- 9.3 years vs 54.5 +/- 10.5 years; p < 0.001), more often female (75% vs 17.4%; p < 0.001), gangrene was uncommon (0% vs 17.4%; p < 0.05), and diffuse involvement was seen more often (43.8% vs 4.4%; p < 0.001). The luminal diameter stenoses were similar before PTA (88.6 +/- 9.7% vs 89.0 +/- 9.1%; p = NS). Higher balloon inflation pressure was required to dilate the lesions of aortoarteritis (9.9 +/- 4.6 ATM vs 5.5 +/- 1.0 ATM; p < 0.001). This group had more residual stenosis (15.5 +/- 12.4% vs 8.3 +/- 9.4%; p < 0.05) after PTA. There were no neurological sequelae, even in PTA of prevertebral lesions. On 3-120 months (mean 43.3 +/- 28.9 months) follow-up of 40 patients, restenosis was more often observed in patients with aortoarteritis, particularly in those with diffuse arterial narrowing. These lesions could be effectively redilated. Clinical symptoms showed marked improvement after successful angioplasty. CONCLUSION: Subclavian PTA is safe and can be performed as effectively in aortoarteritis as in atherosclerosis, with good long-term results. Long-term follow-up shows that it provides good symptomatic relief.

Adult↗
PubMedDate not supplied

High speed rotational atherectomy for diffuse in-stent restenosis: short- and mid-term follow-up results.

Between January 1997 to May 1998, 37 consecutive patients underwent high speed rotational atherectomy with adjunctive balloon angioplasty for the management of first-time diffuse variety of in-stent restenosis in the native coronary arteries. Their age ranged from 38 to 71 years (mean 54.3 +/- 9.7 years). All the patients underwent initial stent implantation at moderate to high pressure. Patients were either symptomatic or demonstrated significant ischaemia by non-invasive testing. The median time from the index procedure to in-stent restenosis was 20 weeks (range 9-40 weeks). Majority (78.1%) of lesions were in the territory of left anterior descending coronary artery. The mean lesion length was 24.3 +/- 8.3 mm (range 12-42 mm). Five lesions each (12.2%) were total occlusion and ostial in location. High speed rotational atherectomy was performed using stepped burr technique in majority (90.2%) with the largest burr corresponding to approximately 70 percent of the reference vessel diameter. The initial burr size ranged from 1.5-2.0 mm, final burr was 1.75-2.25 mm and the average number of burrs used per target vessel was 2.2 +/- 0.3 (range 1-3). Adjunctive balloon angioplasty was performed in all (100%) cases using a semi-compliant oversized balloon (balloon-to-artery ratio 1.1:1) inflated at a pressure of 6.5 +/- 2.1 atmospheres (range 4-10). The procedure was successful in all cases without any major complications (death, Q-MI, CABG or repeat PTCA). Over a median follow-up of 10 months, 27 (73%) patients were asymptomatic. Recurrence of clinical events occurred in 10 (27%) patients at median interval of 16 weeks after rotational atherectomy. Angina was controlled on drug therapy in six (16.2%) and target vessel revascularisation was required in three (8.1%) cases. By the Kaplan-Meier estimate, an event-free survival (absence of death, Q-MI, recurrence of angina, target vessel revascularisation) was 97.3, 94.6, 75.7 and 72.6 percent at 1, 3, 6 and 12 months, respectively. Thus, rotational atherectomy using a stepped burr approach for adequate debulking, followed by adjunctive balloon angioplasty is safe with excellent in-hospital results for the treatment of diffuse in-stent restenosis. Although recurrence of symptoms develops in approximately one-fourth of patients on follow-up, it is much less than reported with balloon angioplasty in this subgroup of patients.

Adult↗
PubMedDate not supplied

Long-term follow-up results after plain balloon coronary angioplasty.

Between September 1987 and June 1992, 571 patients of coronary artery disease underwent percutaneous transluminal coronary angioplasty in our institute. Their ages ranged from 31-82 years (mean 51 +/- 9) and majority (88.3%) were males. At baseline, 318 (55.7%) patients had chronic stable angina, 184 (32.2%) unstable angina, and 57 (10%) underwent PTCA for recurrence of angina in the post-infarction period. Single vessel angioplasty was performed in 406 (71.1%), two-vessel angioplasty in 121 (21.2%) and three or more vessels were dilated in 44 (7.7%). The procedure was successful in 524 (91.8%) patients. Follow-up was available in 438 (83.6%) patients, and ranged from 78 to 135 months (mean 89 +/- 29) with all the patients completing at least 60 months of follow-up. Using Kaplan-Meier statistical analysis, event-free survival (freedom from repeat percutaneous transluminal coronary angioplasty, myocardial infarction, coronary artery bypass surgery, or death) was 72.5 percent at three, 68.0 percent at five, 61.8 percent at seven and 55.6 percent at 10 years of follow-up. Freedom from major adverse cardiac events (myocardial infarction, coronary artery bypass surgery or death) was 88.3, 85.8, 82.0 and 75.4 percent at 3, 5, 7 and 10 years, respectively. Overall survival was 97.4 and 95.2 percent, respectively at 5 and 10 years. Subgroup analysis for all major events was done between males and females, diabetics and non-diabetics, previous history or absence of myocardial infarction, stable versus unstable angina and single versus multivessel disease. Event-free survival rates were compared between the groups using log rank test. On follow-up, the need for surgical revascularisation was more in males compared to females although statistically insignificant, and in patients with unstable angina compared to stable angina (p < 0.02). Similarly, freedom from major adverse cardiac events was significantly better in females compared to males (p < 0.05) and in stable versus unstable angina (p < 0.01). Event-free survival (repeat percutaneous transluminal coronary angioplasty, myocardial infarction, coronary artery bypass surgery, death) was also significantly better in patients with stable angina (p < 0.02). The other outcomes were comparable in all the subgroups. In conclusion, plain balloon angioplasty provides excellent long-term results in patients with coronary artery disease in terms of reduction in major adverse cardiovascular events and need for subsequent revascularisation.

Adult↗