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Samin K Sharma

Publications and source records attributed to Samin K Sharma.

33 records · Page 2Linked to original sources
PubMed2004

Current status of rotational atherectomy.

Despite the increasing use of percutaneous transluminal coronary angioplasty and intracoronary stent placement for the treatment of obstructive coronary artery disease, a large subset of coronary lesions cannot be adequately treated with balloon angioplasty and/or intracoronary stenting alone. Such lesions are often heavily calcified or fibrotic and undilatable with the present balloon technology and attempts to treat them with balloon angioplasty or intracoronary stent placement often lead to vessel dissection or incomplete stent deployment with resultant adverse outcomes. Rotational atherectomy remains a useful niche device for the percutaneous treatment of such complex lesions, usually as an adjunct to subsequent balloon angioplasty and/or intracoronary stent placement. In contrast to balloon angioplasty or stent placement that widen the coronary lumen by displacing atherosclerotic plaque, rotational atherectomy removes plaque by ablating the atherosclerotic material, which is dispersed into the distal coronary circulation. Other lesion subtypes amenable to treatment with this modality include ostial and branch-ostial lesions, chronic total occlusions, and in-stent restenosis. This review discusses the technique and principles of rotational atherectomy, the various treatment strategies for its use (including adjunctive pharmacotherapy), the lesion-specific applications for this device, and the complications unique to this modality. Recommendations are also made for its use in the current interventional era.

Angioplasty, Balloon, Coronary↗
PubMed2004

Randomized trial of Rotational Atherectomy Versus Balloon Angioplasty for Diffuse In-stent Restenosis (ROSTER).

BACKGROUND: Various autopsy and intravascular ultrasound (IVUS) studies have shown neointimal proliferation as the main mechanism of in-stent restenosis (ISR) responsible for >95% of luminal narrowing while stent struts are not compressed. ISR of diffuse type has a high incidence of recurrence (up to 70%) after balloon angioplasty (PTCA). Tissue ablation with percutaneous rotational coronary atherectomy (PRCA) may be more efficacious compared to tissue compression or extrusion after PTCA for the interventional treatment of diffuse ISR. METHODS: The Rotational Atherectomy Versus Balloon Angioplasty for Diffuse In-Stent Restenosis (ROSTER) trial is a single-center, randomized trial comparing PRCA to PTCA (both with IVUS guidance) in the treatment of diffuse ISR in 200 patients. In the PRCA group (n = 100), rotablation was performed using a burr-to-artery ratio >0.7 followed by adjunctive balloon dilatation at low pressure (4-6 atm). In the PTCA group (n = 100), high-pressure (>12 atm) balloon dilatation was performed using an optimal size balloon. The study's primary end point was target lesion revascularization (TLR) at 9 months and secondary end points included clinical events at 1 year and angiographic restenosis in a substudy of the last 75 patients enrolled. RESULTS: Baseline clinical and angiographic variables were comparable between the 2 groups with similar procedural and angiographic success, but a higher rate of repeat stenting occurred in the PTCA group (31% vs 10%; P <.001). Although the angiographic acute luminal gain was similar between the 2 groups, IVUS analysis revealed lower residual intimal hyperplasia area after PRCA versus PTCA (2.1 +/- 0.9 mm2 vs. 3.3 +/- 1.8 mm2; P =.005). At a mean follow-up of 12 +/- 2 months, there were 2 deaths, 3 myocardial infarctions, and 3 coronary artery bypass graft procedures in each group. TLR incidence was 32% in the PRCA group and 45% in the PTCA group (P =.042), with a similar trend noted in the angiographic substudy. CONCLUSION: The ROSTER trial for diffuse ISR revealed both PRCA and PTCA to be safe and effective, but PRCA resulted in less residual intimal hyperplasia, lower repeat stent use, and decreased TLR.

Aged↗
PubMed2003

A comparative study of rotational atherectomy in acute and stable coronary syndromes in the modern era.

Percutaneous rotational coronary atherectomy (PRCA) is commonly used in the percutaneous treatment of diffuse, calcified coronary lesions in stable coronary syndromes (SCSs) and facilitates successful delivery and deployment of balloons and stents. Early experience with PRCA cautioned its use in acute coronary syndromes (ACSs). However, the evolution of the PRCA technique and improved antiplatelet pharmacotherapy has broadened its use in ACSs also. A total of 1,112 consecutive patients with an ACS (n=269) or SCS (n=843) who underwent PRCA of 1,483 lesions were examined retrospectively to evaluate the angiographic and short-term clinical outcomes. Troponin-I was elevated in 33.3% of the ACS group and in 0.6% of the SCS group at baseline (p<0.001). Angiographic complications occurred more frequently in the ACS group (18.6% vs 13.1%, p=0.02). There was no difference in major complications between the groups (ACS 1.1% vs SCS 0.8%; p=0.44). The incidence of any periprocedural creatinine kinase-MB elevation was 17.1% versus 18.9% (p=NS) and 30-day major adverse cardiac events (death, disabling stroke, creatine kinase-MB >3 times the upper limit of normal, urgent revascularization) was 5.9% versus 4.6% (p=NS) when comparing the ACS and SCS groups, respectively. With current techniques and antiplatelet therapy, PRCA can be safely performed in ACSs when lesion morphology dictates, with outcomes comparable to that achieved in SCSs. Although angiographic complications occurred more frequently in the ACS group, this did not result in a significantly higher incidence of postprocedural myonecrosis or 30-day major adverse cardiac events.

Acute Disease↗
PubMed2003

Prediction of outcome after percutaneous coronary intervention for the acute coronary syndrome.

BACKGROUND: The seven-component Thrombolysis In Myocardial Infarction (TIMI) score has been used to risk stratify, and to guide the medical management of, patients with unstable angina or non-ST-elevation myocardial infarction. We assessed the usefulness of the risk score in predicting in-hospital and 30-day outcomes in such patients who were undergoing percutaneous coronary intervention. METHODS: Using the TIMI score, 2501 patients with unstable angina or non-ST-elevation myocardial infarction were divided into low-risk (zero to two risk factors; n = 974), intermediate-risk (three to four risk factors; n = 1339), and high-risk (five to seven risk factors; n = 188) groups, and outcomes were compared. RESULTS: Angiographic/clinical success and the rate of minor procedural events were similar among the three groups. A higher TIMI risk score was associated with more cardiac comorbid conditions and more complicated angiographic lesions: longer lesions (P = 0.0009), more thrombotic lesions (P = 0.03), more multivessel disease (P <0.0001), and more American College of Cardiology/American Heart Association type B2/C lesions (P = 0.05). Although the risk score did not predict interventional technical success or intraprocedural complications, a high score was associated with prolonged hospital stay, higher postprocedural peak troponin levels, and 30-day major adverse cardiac events. Stepwise logistic regression showed that in conjunction with lesion length and patient sex, a high score was an independent predictor of 30-day major adverse cardiac events (odds ratio = 2.3; 95% confidence interval: 1.1 to 4.1; C statistic = 0.62). CONCLUSION: Although a higher TIMI risk score in patients with unstable angina or non-ST-elevation myocardial infarction who were undergoing percutaneous coronary intervention correlated with adverse clinical outcome, the score alone cannot be used to guide diagnostic or therapeutic strategies.

Acute Disease↗
PubMed2003

The activated clotting time can be used to monitor the low molecular weight heparin dalteparin after intravenous administration.

OBJECTIVES: This study was designed to compare the dose response of dalteparin versus unfractionated heparin (UFH) on the activated clotting time (ACT), and to determine whether the ACT can be used to monitor intravenous (IV) dalteparin during percutaneous coronary intervention (PCI). BACKGROUND: The use of low molecular weight heparin (LMWH) during PCI has been limited by the presumed inability to monitor its anticoagulant effect using bedside assays. METHODS: This study was performed in three phases. In vitro, ACTs were measured on volunteer (n = 10) blood samples spiked with increasing concentrations of dalteparin or UFH. To extend these observations in vivo, ACTs were then measured in patients (n = 15) who were sequentially treated with IV dalteparin and then UFH. Finally, a larger monitoring study was undertaken involving patients (n = 110) who received dalteparin 60 or 80 international U (IU)/kg alone or followed by abciximab. We measured ACT (Hemochron), activated partial thromboplastin time (aPTT), plasma anti-Xa and anti-IIa levels, tissue factor pathway inhibitor (TFPI) concentration, and plasma dalteparin concentration. RESULTS: Dalteparin induced a significant rise in the ACT with a smaller degree of variance as compared to UFH. Five min after administration of IV dalteparin 80 IU/kg the ACT increased from 125 s (122 s, 129 s) to 184 s (176 s, 191 s) (p < 0.001). The aPTT, anti-Xa and anti-IIa activities, and TFPI concentration also demonstrated significant increases following IV dalteparin. CONCLUSIONS: The ACT and aPTT are sensitive to IV dalteparin at clinically relevant doses. These data suggest that the ACT may be useful in monitoring the anticoagulant effect of intravenously administered dalteparin during PCI.

Aged↗
PubMed2003

Postprocedure chest pain after coronary stenting: implications on clinical restenosis.

OBJECTIVES: The goal of this study was to analyze the incidence and predictors of postprocedure chest pain (PPCP) after percutaneous coronary intervention (PCI) and its correlation with clinical restenosis. BACKGROUND: Chest pain after PCI occurs frequently even in the absence of procedural events and is considered to be due to vasospasm or coronary artery stretch. The short- and long-term significance of PPCP after otherwise successful stenting is not clear. METHODS: We analyzed 1,362 patients undergoing coronary stenting for PPCP, procedural and in-hospital events, 30-day major adverse cardiac events, and target vessel revascularization (TVR) at 6 to 9 months. RESULTS: There were 488 patients with PPCP and, of these, 312 patients were excluded due to procedural events. The remaining 176 patients with PPCP were compared with 874 patients without PPCP. Creatine kinase-MB isoenzyme elevation occurred in 25.6% of the PPCP group versus 9.6% of the no PPCP group (p < 0.001). Despite similar reference vessel diameter, the PPCP group had larger postprocedure minimum lumen diameter, higher stent-to-vessel ratio, and higher inflation pressure versus the no PPCP group (p < 0.01). At 30 days, the emergency room visits and repeat catheterization (16% vs. 2.7%; p < 0.001) were higher in the PPCP group versus the no PPCP group, but repeat intervention was similar. At 6- to 9-month follow-up, the TVR was significantly higher in the PPCP group compared with the no PPCP group (29.5% vs. 16.6%; p < 0.01). CONCLUSIONS: Our analysis suggests micromyonecrosis and vessel stretch as causes of PPCP. Postprocedure chest pain is associated with similar short-term outcome as no PPCP, but has higher restenosis, perhaps mediated by deep vessel wall injury. Therefore, PPCP may identify patients at high risk for restenosis.

Aged↗
PubMed2003

Comparison of rotational atherectomy with conventional balloon angioplasty in the prevention of restenosis of small coronary arteries: results of the Dilatation vs Ablation Revascularization Trial Targeting Restenosis (DART).

BACKGROUND: The optimum treatment of obstructive coronary disease in small (<3.0 mm diameter) arteries remains unknown. Rotational atherectomy is an approved treatment that might reduce the vascular injury during percutaneous coronary intervention compared with angioplasty. We report on a multicenter, randomized, blinded end point trial comparing rotational atherectomy with balloon angioplasty in the prevention of restenosis of obstructed small coronary arteries. METHODS: A total of 446 patients with myocardial ischemia associated with an angiographic stenosis in a native coronary artery 2 to 3 mm in diameter and < or =20 mm in length without severe calcification were randomly assigned to receive rotational atherectomy (n = 227) or balloon angioplasty (n = 219). The primary end point was target vessel failure at 12 months (defined as the composite of death, Q-wave myocardial infarction, and clinically driven repeat revascularization of the target vessel). RESULTS: The mean reference vessel diameter was 2.46 +/- 0.40 mm, the mean lesion length was 9.97 +/- 5.59 mm, and the prevalence of diabetes mellitus was 32%. Acute procedural success (91.6% for rotational atherectomy, 94.1% for balloon angioplasty, P =.36) and target vessel failure at 12 months were not significantly different (30.5% vs 31.2%, P =.98). At 8 months, there were no significant differences in minimum lumen diameter (1.28 +/- 0.63 mm vs 1.19 +/- 0.54 mm, P =.26), percent diameter stenosis (28% +/- 12% vs 29% +/- 15%, P =.59), binary restenosis rate (50.5% vs 50.5%, P = 1.0), or late loss index (0.57 vs 0.62, P =.7). No Q-wave myocardial infarctions occurred in either arm of the study, and non-Q-wave myocardial infarctions (defined as creatine kinase level >2 times normal with an elevated creatine kinase-myocardial band isoenzyme level) occurred in 2.2% and 1.4% of the patients in the rotational atherectomy and balloon angioplasty groups, respectively (P =.72). CONCLUSION: Rotational atherectomy was found to be safe in the treatment of obstructed small arteries, but lower rates of target vessel failure were not achieved compared with balloon angioplasty. Because the acute gain and loss index ratios of the 2 treatments were similar, there was no evident beneficial antirestenosis mechanism seen for rotational atherectomy.

Angioplasty, Balloon, Coronary↗
PubMed2002

Refractory angina pectoris: mechanism and therapeutic options.

As the survival of patients with primary coronary events continues to increase, the number of patients presenting with coronary artery disease unsuitable to further revascularization techniques and symptoms refractory to medical therapy also continues to rise. The aims of this review were to define the population of patients with refractory angina pectoris and to present the therapeutic options currently available for this condition. Refractory angina pectoris is defined, and traditional medical therapies are discussed. Then, current therapeutic options for patients with refractory angina are extensively reviewed. A multitude of therapeutic options exist for patients with refractory angina pectoris. Small, uncontrolled studies have shown a potential benefit for additional antiplatelet and antithrombotic therapy. In randomized trials, neurostimulation has been shown to be effective in reducing angina symptoms. Enhanced external counterpulsation is a viable treatment option for select patients with refractory angina. In many randomized trials, laser revascularization has been shown to diminish angina symptoms, although no placebo-controlled studies exist to date. Gene therapy is a promising area of research in this field. Percutaneous in situ coronary venous arterialization is in its infancy, but may be able to treat many patients if proved successful. No data support the role of chelation therapy in this population. Heart transplantation remains a final option for these patients. Further research of the techniques mentioned in this review is warranted. The importance of randomized, double-blinded, placebo-controlled trials cannot be overemphasized, as the placebo effect of these therapies is probably marked.

Angina Pectoris↗
PubMed2002

A protocol for prevention of radiographic contrast nephropathy during percutaneous coronary intervention: effect of selective dopamine receptor agonist fenoldopam.

Radiographic contrast nephropathy (RCN), acute worsening of renal function due to contrast agents, can occur in 15%-40% of patients with baseline renal dysfunction undergoing percutaneous coronary intervention (PCI) and is associated with increased morbidity and in-hospital mortality. The purpose of this study was to evaluate whether the selective dopamine-1 (DA-1) receptor agonist fenoldopam would be beneficial in patients with chronic renal insufficiency (CRI) undergoing PCI and also to design a protocol for prevention of RCN. We analyzed 150 consecutive patients with CRI [baseline serum creatinine (BSCr) +/- 1.5% mg] who underwent PCI and received fenoldopam during and after the procedure, in addition to saline hydration. RCN, defined as > 25% increase of BSCr 48-72 hr after PCI, occurred in 4.7% (n = 7) of 150 PCI patients receiving fenoldopam and 3.5% in diabetics (n = 85) vs. 6.1% in nondiabetics (n = 65; P = NS). No patients required dialysis. The observed 4.7% incidence of RCN with fenoldopam was significantly lower than 18.8% incidence in the historical control group (P < 0.001). Our data suggest that fenoldopam is a useful adjunct in the prevention of RCN during PCI, especially in diabetics.

Aged↗
PubMed2002

Normal coronary arteries and isolated, regional, left ventricular dysfunction in myotonic dystrophy: a case report.

Development of cardiomyopathy in myotonic dystrophy is rare. Regional ventricular abnormality in the presence of normal coronary vessels has not been reported in this condition. We describe a case of isolated, regional, left ventricular dysfunction with corresponding defects on nuclear perfusion imaging in a patient with classical myotonic dystrophy and normal coronary arteries.

Adult↗
PubMedDate not supplied

Contrast-associated nephropathy.

Contrast-associated nephropathy (CaN) has become a major cause of iatrogenic acute renal failure, especially with the increasing use of radiographic contrast media in both diagnostic and interventional procedures. CaN is the third most common cause of iatrogenic acute renal failure, and is associated with increased morbidity and in-hospital mortality. CaN typically presents as an acute rise in serum creatinine levels, usually within 48 hours after exposure to contrast media. Renal medullary ischemia secondary to contrast-induced vasoconstriction is now believed to be the most likely cause of CaN, although direct renal tubular cytotoxicity does appear to play a role. The occurrence of CaN is directly related to the number of coexisting clinical risk factors. Among the many risk factors, preexisting renal impairment, the presence of diabetes mellitus and the volume of the contrast agent administered are the most important. The most effective means of reducing the incidence of CaN is through prevention, by first identifying the risk factors and then attempting to correct for them before the administration of contrast material. Although the earliest and most well-tested preventive measure, namely intravenous hydration, continues to be the most effective way to prevent CaN, recent studies have provided many new preventive modalities. The growing use of these new agents, such as acetylcysteine, endothelin blockers, and most recently fenoldopam, has increased the options available for the prevention of CaN.

Acetylcysteine↗