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Biomedical subjects

Samir R Kapadia

Publications and source records attributed to Samir R Kapadia.

At least 19 recordsLinked to original sources
PubMed2006

Coronary artery calcification and changes in atheroma burden in response to established medical therapies.

OBJECTIVES: This study sought to determine the relationship between coronary calcification and plaque progression in response to established medical therapies. BACKGROUND: Coronary calcification correlates with the extent of atherosclerosis and predicts clinical outcome. METHODS: Atheroma volume was determined in serial intravascular ultrasound pullbacks in matched arterial segments of 776 patients with angiographic coronary artery disease. A calcium grade at baseline was assigned for each image (total 28,876) (0 = no calcium, 1 = calcium with acoustic shadowing <90 degrees and 2 = calcium with shadowing >90 degrees). Patients with a calcium index (average of calcium scores in a pullback) below versus above the median were compared with regard to plaque burden and progression. RESULTS: Patients with a high calcium index were older (59 vs. 54 years, p < 0.001), more likely to be male (80% vs. 68%, p < 0.001), and more likely to have a history of hypertension (71% vs. 64%, p = 0.03). These patients had a greater percentage atheroma volume (PAV) (45% vs. 34%, p < 0.001), total atheroma volume (TAV) (210 vs. 151 mm3, p < 0.001), and percentage of images with maximal plaque thickness >0.5 mm (93% vs. 72%, p < 0.001). The continuous rate of change in PAV (1.1 +/- 0.4% vs. 0.8 +/- 0.4%, p = 0.34) and TAV (1.7 +/- 2.1% vs. -0.1 +/- 2.2%, p = 0.37) was similar in patients with a lower and higher calcium index, respectively. A lower calcium index was associated with a higher rate of patients showing substantial change in atheroma burden (at least 5% change in PAV, 70% vs. 53%, p < 0.001). CONCLUSIONS: Calcific plaques are more resistant to undergoing changes in size in response to systemic interventions targeting atherosclerotic risk factors.

Adult↗
PubMed2006

In vivo analysis of the anatomical relationship of coronary sinus to mitral annulus and left circumflex coronary artery using cardiac multidetector computed tomography: implications for percutaneous coronary sinus mitral annuloplasty.

OBJECTIVES: We sought to determine the in vivo anatomical relationships between mitral annulus (MA) and coronary sinus (CS) as well as CS and left circumflex coronary artery using cardiac computed tomography. BACKGROUND: Percutaneous treatment of mitral regurgitation (MR) by annuloplasty via CS is under development. Success of such treatment depends on the close anatomical proximity of the MA to the CS. The in vivo data regarding this anatomical relationship in humans are scant. We investigated this relationship using contrast multidetector computed tomography. METHODS: We studied 25 normal individuals and 11 patients with severe MR (3 to 4+) due to mitral valve prolapse. Separation between MA and CS was measured in standard planes, in 4-chamber (4C), 2-chamber (2C), and 3-chamber views. Distance from ostium of CS to the intersection with left circumflex (LCX), and anatomical relation of LCX and CS were determined using 3-dimensional mapping (Philips Brilliance, Philips Medical Systems, Amsterdam, the Netherlands). RESULTS: There was significant variance of CS to MA separation at all planes. Separation of CS and MA was increased in lateral location (4C) and decreased in posterior location (2C) in the MR group with increase in MA size. Left circumflex artery crossed between CS and MA in 80% of patients. The LCX crossed CS at a variable distance from the ostium of CS (86.5 +/- 21 mm, range 37 to 123 mm) CONCLUSIONS: There is significant variability in the relation of CS to MA in humans. Coronary sinus to MA distance increases in patients with severe MR and annular dilation, mainly in the posterolateral location. The left circumflex crosses under the CS the majority of times, but with a significant variability in the location where it crosses the CS. These anatomical features should be taken into consideration while selecting percutaneous treatment strategies for mitral valve repair.

Adult↗
PubMed2006

Use of percutaneous transluminal septal myocardial ablation for relief of outflow tract obstruction in cardiac amyloidosis: a novel therapeutic target.

Cardiac amyloidosis typically presents with diastolic heart failure, but asymmetrical septal hypertrophy with outflow tract obstruction has been described. We illustrate the case of a 71-year-old woman with biopsy-proven cardiac amyloidosis and severe medical comorbidities with refractory severe heart failure who had asymmetric septal hypertrophy, systolic anterior motion (SAM) of the mitral valve, and a resting left ventricular outflow tract gradient of 86 mm Hg, increasing to 102 mm Hg on Valsalva maneuver. She underwent percutaneous transluminal septal myocardial ablation (PTSMA) with a dramatic resolution of her SAM and outflow tract obstruction, confirmed by intracavitary pressure wire measurements. PTSMA is technically feasible in this context, and correction of outflow tract obstruction may represent a new therapeutic target in cardiac amyloidosis.

Aged↗
PubMed2005

Slow-flow phenomenon during carotid artery intervention with embolic protection devices: predictors and clinical outcome.

OBJECTIVES: The purpose of this research was to define the predictors of the "slow-reflow" phenomenon during carotid artery intervention with filter-type embolic protection devices (EPDs) and to determine its prognostic significance. BACKGROUND: During carotid artery intervention using filter-type EPDs, we have observed cases in which there is angiographic evidence of a significant reduction in antegrade flow in the internal carotid artery proximal to the filter device, termed "slow-flow." The predictors of this phenomenon and its prognostic significance are unknown. METHODS: Using a single-center prospective carotid intervention registry, patients with slow-flow were compared to patients with normal flow during carotid intervention with respect to clinical, procedural, and lesion characteristics, and the 30-day incidence of death and stroke. RESULTS: A total of 414 patients underwent 453 carotid artery interventions using EPDs. Slow-flow occurred in 42 patients (10.1%) undergoing 42 carotid interventions (9.3%), and most commonly occurred after post-stent balloon dilatation (71.4%). Multivariate logistic regression analysis identified the following predictors of slow-flow: recent history (<6 months) of stroke or transient ischemic attack (odds ratio [OR] 2.8, 95% confidence interval [CI] 1.4 to 5.6, p = 0.004), increased stent diameter (OR 1.4, 95% CI 1.02 to 1.94, p = 0.044), and increased patient age (OR 1.05, 95% CI 1.01 to 1.09, p = 0.025). Among patients with slow-flow, the 30-day incidence of stroke or death was 9.5% compared to 2.9% in patients with normal flow (chi-square = 4.73, p = 0.03). This difference was driven by the disparity in the 30-day incidence of stroke (9.5% vs. 1.7%). CONCLUSIONS: Slow-flow during carotid intervention with EPDs is a frequent event that is associated with an excess risk of periprocedural stroke. The association of the phenomenon with clinically symptomatic carotid lesions and use of larger stent diameters suggests that embolization of vulnerable plaque elements may play a pathogenic role.

Aged↗
PubMed2005

Intravascular ultrasound evidence of angiographically silent progression in coronary atherosclerosis predicts long-term morbidity and mortality after cardiac transplantation.

OBJECTIVES: The aim of this study was to determine whether angiographically silent early coronary intimal thickening could predict long-term morbidity and mortality. BACKGROUND: Although intravascular ultrasound (IVUS) is widely used to detect early transplant coronary disease, its prognostic significance has not been well defined. METHODS: The study cohort consisted of 143 patients who underwent early multivessel (2.1 +/- 0.7 arteries/patient) IVUS examination 1.0 +/- 0.5 month and 12.0 +/- 1.0 month after transplantation. The change in intimal thickness was evaluated using paired analysis of 1,069 matched sites. Rapidly progressive vasculopathy was defined as the change in intimal thickness >/=0.5 mm. Patients were followed for a primary end point of all-cause mortality and a secondary composite end point of mortality and nonfatal myocardial infarction (MI). Angiographic disease, defined as any >/=50% diameter stenosis, was assessed in 126 patients. RESULTS: Intravascular ultrasound at one year demonstrated rapid progression in 54 (37%) of 143 patients and new lesions in 67 (47%) of 143 of patients. At a mean clinical follow-up of 5.9 years, more patients with rapidly progressive vasculopathy died, as compared with those without (26% vs. 11%, p = 0.03). Death and MI also occurred more frequently among those with rapid progression than in those without it (51% vs. 16%, p < 0.0001). There was no significant difference in outcome in patients with and without donor-transmitted lesions. Angiographic disease was found in 11 (22%) of 50 patients with and in 2 (2.1%) of 76 patients without (p = 0.003) rapidly progressive vasculopathy. The IVUS-defined rapid progression correlated highly with future development of angiographic disease (p = 0.0005). CONCLUSIONS: Rapidly progressive vasculopathy by IVUS, defined as an increase of >/=0.5 mm in intimal thickness within the first year after transplantation, is a powerful predictor of all-cause mortality, MI, and angiographic abnormalities. Accordingly, such patients may be candidates for more aggressive anti-atherosclerotic and/or immunosuppressive therapy.

Adult↗
PubMed2005

Effect of chronic total coronary occlusion on treatment strategy.

In a registry analysis of 8,004 consecutive patients presenting for diagnostic catheterization at a single institution from 1990 to 2000, chronic total occlusion (CTO) was found in 52% of patients with significant (> or = 70% diameter stenosis) coronary artery disease. Peripheral vascular disease was the strongest clinical predictor of the presence of a CTO. In a multivariate analysis, CTO was the strongest predictor against the selection of percutaneous coronary intervention (PCI) as a treatment strategy, indicating that efforts to improve the success rate of PCI in CTO may have a significant impact on management of coronary disease.

Angioplasty, Balloon, Coronary↗
PubMed2005

Evaluation of left ventricular outflow tract area after septal reduction in obstructive hypertrophic cardiomyopathy: a real-time 3-dimensional echocardiographic study.

BACKGROUND: The comparative impact of percutaneous alcohol septal reduction (ASR) and surgical myectomy on the left ventricular outflow tract (LVOT) area in patients with obstructive hypertrophic cardiomyopathy (HC) is not well defined. Real-time 3-dimensional echocardiography (RT3DE) provides accurate information about the LVOT geometry and shape. We aimed to analyze the change in LVOT area after septal reduction interventions in patients with obstructive HC using RT3DE. METHODS: Thirty-one HC patients (mean age 53 +/- 17 years) undergoing ASR (n = 14) or myectomy (n = 17) were studied at baseline and during follow-up with RT3DE. LVOT area was measured after observing the LVOT in the 3D space as the smallest area during midsystole. LVOT pressure gradients were determined by conventional continuous wave Doppler. RESULTS: Overall, LVOT area increased from 0.86 +/- 0.20 to 2.50 +/- 0.88 cm2 (P < .01), and the resting LVOT pressure gradient decreased from 64 +/- 41 to 16 +/- 10 mm Hg (P < .01) after a median follow-up of 3 months after intervention (range 1-24 months). A similar significant decrease in LVOT pressure gradients was seen in myectomy and ASR groups (from 62 +/- 39 to 12 +/- 5 mm Hg and from 67 +/- 43 to 21 +/- 14 mm Hg, respectively, P < .01 in between each group, and P = NS between both groups). However, the increase in LVOT area was greater in myectomy than in ASR group (from 0.81 +/- 0.22 to 2.90 +/- 0.64 cm2 and 0.93 +/- to 0.16 to 2.02 +/- 0.92 cm2, respectively, P < .01 between both groups). CONCLUSION: RT3DE demonstrated an effective increase in LVOT area after both ASR and myectomy. This technique may be useful for assessing the results of septal reduction in patients with obstructive HC.

Adolescent↗
PubMed2005

Patent foramen ovale closure: historical perspective.

The work of the pioneers in PFO closure finally may evolve into a front-line therapy for secondary prevention of stroke in selected patients who have PFO and embolic events. Current implants, although new to most of interventional cardiology and neurology, are the result of years of steady, progressive work. It seems that PFOclosure is here to stay and will become a key element in a collaborative approach between cardiology and neurology in the treatment of embolic stroke. The advances in device technology may make PFO closure sufficiently safe, effective,and durable that it may become one of the most frequent catheter laboratory procedures to be performed.

Heart Septal Defects, Atrial↗
PubMed2005

Advances in percutaneous valvular intervention.

We are entering a new era in the percutaneous treatment of valvular heart disease. Novel techniques and devices have given rise to the possible treatment of a range of valvular heart diseases that previously necessitated surgical therapies, including aortic stenosis, pulmonary regurgitation and mitral regurgitation. Despite the enormous potential of these percutaneous therapies, enthusiasm needs to be balanced by an understanding of the challenges that need to be overcome before such therapies can be widely embraced. This review provides a critical assessment of the status of the major developments in percutaneous valvular intervention to date, and provides the authors' perspective on the current role and future potential of these techniques.

Angioplasty, Balloon, Coronary↗
PubMed2004

Feasibility of simultaneous bilateral carotid artery stenting.

Due to the progressive aging of the population, severe bilateral carotid stenosis has become a more frequent condition. On occasion, simultaneous revascularization may be appropriate. There is increased evidence that for these high-risk patients, a percutaneous revascularization may be the best approach. However, there are concerns that simultaneous bilateral carotid stenting may be associated with cerebral hyperperfusion, excessive bradycardia, and hypotension. We report a series of 10 consecutive patients who underwent simultaneous bilateral carotid stenting. All of these patients were not deemed to be surgical candidates due to high-risk comorbidities. All but one of the lesions were successfully stented. There were no procedural deaths, myocardial infarctions, or strokes. Thus, among carefully selected patients, simultaneous bilateral carotid artery stenting is a promising, technically feasible option.

Adrenergic alpha-Agonists↗
PubMed2004

Hemodynamic effects of the angiotensin-converting enzyme inhibitor, ramipril, in patients with mild to moderate aortic stenosis and preserved left ventricular function.

BACKGROUND: Angiotensin-converting enzyme (ACE) inhibitor use is presumed to be contraindicated in patients with aortic stenosis (AS). We determined the hemodynamic effects of ACE inhibitors in patients with mild to moderate aortic stenosis (AS) and preserved left ventricular function. METHODS: Thirteen elderly patients (mean [SD] age = 65 [17] years), with mild to moderate AS (aortic jet velocity 2.5-4.0 m/s), normal left ventricular and renal function, and no clinical coronary artery disease, were enrolled in a single-center, open-label trial comparing the hemodynamic effects at baseline and following titration of ramipril to a maximum dose of 7.5 mg twice daily. Patients were identified from echocardiography laboratory logs. Despite a presumed contraindication to ACE inhibitor use in AS patients, 30% (71 of 235) of patients otherwise meeting inclusion or exclusion criteria were excluded owing to current ACE inhibitor use. Patients were monitored with weekly clinic visits, biweekly laboratory tests, and monthly echocardiograms. RESULTS: There were no significant changes from baseline to week 8 in echocardiographic parameters, including mean (SD) aortic jet velocity [2.9 (0.4) vs 2.9 (0.4) m/s], calculated aortic transvalvular gradient [18 (6) vs 18 (6) mm Hg], or cardiac output [5.5 (1.2) vs 6.0 (2.1) L/min], or significant changes in blood pressure or heart rate. Early discontinuations were for asymptomatic low blood pressure (one patient) or a reversible creatinine increase of 0.3 mg/dL (one patient). CONCLUSIONS: Short-term treatment with up to 7.5 mg twice daily of ramipril was well tolerated in patients with mild to moderate AS and preserved left ventricular function. A surprisingly high proportion of patients with documented AS were already receiving ACE inhibitors.

Adult↗
PubMed2003

Coronary plaque morphology and frequency of ulceration distant from culprit lesions in patients with unstable and stable presentation.

OBJECTIVE: Intravascular ultrasound studies describe ruptured coronary plaques at sites remote from the culprit lesion in patients with acute myocardial infarction (MI), suggesting multifocal plaque vulnerability. However, the role of intravascular ultrasound in the diagnosis of lesion vulnerability before rupture is unclear. METHODS AND RESULTS: We compared morphology and frequency of ulceration of additional plaques proximal to the culprit lesion in 105 patients treated with emergent stenting during an evolving, acute MI in the CADILLAC study and 92 patients with stable/subacute presentation who underwent elective stenting. Additional plaques proximal to the culprit lesion were found in 52 (50%) and 54 (59%) patients in the acute MI and stable/subacute group, respectively. The prevalence of ulceration was significantly higher in the acute MI than in the stable/subacute group (19% versus 4%; P=0.014). However, there was no significant difference in other morphological lesion characteristics. CONCLUSIONS: Additional plaques are frequently found adjacent to the culprit lesions in patients undergoing percutaneous coronary intervention independent of clinical presentation. The increased prevalence of plaque ulceration but otherwise similar morphology of additional lesions in patients with acute MI versus stable/subacute presentation demonstrates the limitations of imaging in the assessment of plaque vulnerability.

Angina Pectoris↗
PubMed2003

Repeated intravascular ultrasound imaging in cardiac transplant recipients does not accelerate transplant coronary artery disease.

OBJECTIVES: This study was designed to examine the impact of repeated intravascular ultrasound (IVUS) examinations on transplant coronary artery disease (CAD). BACKGROUND: Serial IVUS is the most accurate method for early detection and surveillance of transplant CAD. However, the long-term safety of serial IVUS exams is not well described. Accordingly, we examined the impact of repeated IVUS examinations on transplant CAD. METHODS: We examined 226 transplant recipients who underwent one or more IVUS examinations and coronary angiography at least one year after the last IVUS exam. The coronary angiograms were analyzed using quantitative coronary angiography. Vessel diameters, frequency, and severity of stenoses in IVUS-imaged and nonimaged coronary arteries were compared. In a subgroup analysis of 31 patients, angiographic lumen diameters were measured at baseline (within eight weeks of transplantation) and during follow-up (after two, three, or four IVUS studies). RESULTS: In the 226 patients, 548 coronary arteries were previously imaged by IVUS and 130 arteries were not imaged by IVUS. On subsequent angiograms, stenoses were observed in 16.2% (21/130) of nonimaged arteries and 19.5% (107/548) of imaged arteries (p = 0.38). The arterial diameters of nonimaged and imaged arteries were not significantly different (p = 0.07), regardless of the number of IVUS exams and duration of follow-up. Subgroup analysis revealed a significant decrease in vessel lumen diameter over time in nonimaged as well as imaged arteries. The magnitude of the diameter decrease was not significantly different between the two groups. CONCLUSIONS: Repeated IVUS examinations following heart transplantation do not result in angiographically evident acceleration of transplant CAD. Therefore, serial IVUS imaging is a safe method for the detection and surveillance of transplant CAD.

Coronary Angiography↗