Sandeep Nathan

Calcium Antagonists: Effects on Cardio-Renal Risk in Hypertensive Patients

Calcium antagonists comprise 2 main subclasses, dihydropyridines and nondihydropyridines, and have been studied extensively in hypertensive patients. Early meta-analyses suggested that short-acting calcium antagonists were associated with higher mortality rates resulting from cardiovascular events and other etiologies. Recent meta-analyses failed to show any substantive difference between long acting calcium antagonists and other antihypertensive drug classes with regard to cardiovascular outcomes in those with low to moderate cardiovascular risk or kidney disease progression among those with stage 2 or 3 nonproteinuric kidney diseases. The data from calcium antagonist trials are consistent in that they decrease stroke incidence but fail to protect against new-onset heart failure. In people with proteinuric kidney disease, that is >300 mg protein/gram creatinine, use of dihydropyridine calcium antagonists to lower blood pressure without the use of agents that block the renin angiotensin aldosterone system does not provide optimal slowing of nephropathy progression. This relates directly to lack of antiproteinuric effects with this subclass and not seen with nondihydropyridine agents that reduce proteinuria to a greater degree than dihydropyridines. Thus, calcium antagonists are safe and as efficacious as other antihypertensive agents to reduce cardiovascular risk. They should be avoided in people with systolic dysfunction but may be used for blood pressure lowering in people with preserved systolic function. Dihydropyridine calcium antagonists should only be used in conjunction with angiotensin-converting enzyme inhibitors or angiotensin receptor blockers in proteinuric kidney disease because they will not optimally slow kidney function loss in their absence.

Coronary artery disease in young adults

To Thee It Shall Descend With Better Quiet —From Act IV, Scene III, Henry IV, Part II, by William Shakespeare Coronary artery disease (CAD) is a devastating disease precisely because an otherwise healthy person in the prime of life may die or become disabled without warning. When the afflicted

Radial Versus Femoral Access for Percutaneous Coronary Intervention: Implications for Vascular Complications and Bleeding

Since its advent over two decades ago, transradial access for cardiac catheterization and percutaneous intervention has evolved into a versatile and evidence-based approach for containing the risks of access-site bleeding and vascular complications without compromising the technical range or success associated with contemporary percutaneous coronary intervention (PCI). Early studies demonstrated reduced rates of vascular complications and access-site bleeding with radial-access catheterization but at the cost of increased access-site crossover and reduced procedural success. Contemporary data demonstrate that while the rates of major bleeding with femoral-access PCI in standard-risk cohorts have declined significantly over time, the transradial approach still retains significant advantages by way of reductions in vascular complications, length of stay, and enhanced patient comfort and patient preference over the femoral approach, while maintaining procedural success. Major adverse cardiovascular events and bleeding are lowest with the transradial approach when procedures are performed at high-volume radial centers, by experienced radial operators, or in the context of ST-segment elevation myocardial infarction. Choice of procedural anticoagulation appears to differentially impact access-site bleeding in transradial versus transfemoral PCI; however, non-access site bleeding remains a significant contributor to major bleeding in both groups. Despite abundant supporting data, adoption of transradial technique as the default strategy in cardiac catheterization in the United States has lagged behind many other countries. However, recent trends suggest that interest and adoption of the technique in the United States is growing at a brisker pace than previously observed.

Percutaneous Transcatheter Aortic Valve Closure Successfully Treats Left Ventricular Assist Device–Associated Aortic Insufficiency and Improves Cardiac Hemodynamics

OBJECTIVES This study sought to assess the effectiveness of a novel percutaneous method to treat left ventricular assist device (LVAD)-associated severe aortic insufficiency (AI) in a series of patients determined to be poor reoperative candidates. BACKGROUND The increased use of continuous-flow LVAD in advanced heart failure has led to marked changes in the management of patients with this condition. However, secondary AI can become a significant complication. METHODS Five patients with continuous-flow LVAD and severe post-LVAD AI underwent percutaneous transcatheter aortic valve closure from September to October 2011 at a single quaternary care academic medical center. All patients had LVAD implanted as destination therapy. LVAD parameters, hemodynamics, and echocardiographic measurements were obtained before and after aortic valve closure. RESULTS All patients underwent successful closure with the Amplatzer cribriform device (AGA Medical, Plymouth, Minnesota) via a percutaneous transcatheter femoral approach with a significant reduction of AI from severe to trivial. Cardiac hemodynamics improved, and the pulmonary capillary wedge pressure was reduced in all patients. There was no change in mitral or tricuspid regurgitation, LVAD power, or pulsatility index. CONCLUSIONS Percutaneous transcatheter closure of the aortic valve effectively treats LVAD-associated AI and reduces pulmonary capillary wedge pressure. This procedure should be considered to treat LVAD-associated AI in patients who are poor candidates for repeat operation. Further data are needed to assess long-term results.

TCT-379 Percutaneous Transcatheter Aortic Valve Closure Successfully Treats Left Ventricular Assist Device-Associated Aortic Insufficiency and Improves Cardiac Hemodynamics

The increased use of continuous-flow LVADs in advanced heart failure has led to marked changes in the management of patients with this condition. However, secondary AI can become a significant complication. Our objective was to assess the effectiveness of a novel percutaneous method to treat left

The Future of Renal Denervation in Resistant Hypertension

Resistant hypertension, defined as inadequate blood pressure control despite three or more antihypertensive medications at maximally tolerated doses, is strongly linked to increased cardiovascular morbidity and mortality. Increased renal afferent and efferent sympathetic activity carried by nerves which arborize the adventitia of the renal arteries, appears to be central to the pathobiology of resistant hypertension. Historical experience indicates that surgical denervation and/or sympathectomy often dramatically reduced blood pressure in patients with malignant hypertension. Catheter-based radio-frequency renal denervation was developed in the past decade as a percutaneous adaptation of surgical denervation. Percutaneous renal denervation using a variety of systems has demonstrated to date, in non-randomized and unblinded studies, dramatic reductions in office-based blood pressure, but more modest impact on ambulatory blood pressure. The only single, appropriately powered, blinded, sham-controlled study of renal denervation conducted to date, however, failed to meet its primary endpoint, casting doubt on the value of the therapy. Ancillary benefits of renal denervation have been described in such conditions as diabetes mellitus, heart failure, and sleep apnea but require further study. While renal denervation is already widely available outside of the USA for commercial use, its utility in resistant hypertension must be vetted by further rigorous investigation before its use can be routinely recommended.

Association of medical noncompliance and long-term adverse outcomes, after myocardial infarction in a minority and uninsured population

The association of noncompliance with evidence-based medical therapies after myocardial infarction (MI) on long-term outcomes is not well recognized in minority and uninsured populations. Consecutive MI patients at a large urban hospital were followed for compliance with evidence-based medications (aspirin, clopidogrel, statins, beta blockers, and angiotensin converting enzyme inhibitors [ACEIs]/angiotensin receptor blockers [ARBs]). Noncompliance was defined as proportion of days covered < or =80%. The outcome was combined mortality and MI. Kaplan-Meier analyses were used to explore the impact of noncompliance > or =4 medications. Of the 509 patients (86% minorities, 77% uninsured, and 54% diabetics), 132 (25.9%) presented with ST segment elevation with myocardial infarction (STEMI) and 377 (74.1%) with a non-ST segment elevation with myocardial infarction (NSTEMI), revascularization was performed in 297 (58.4%) patients, 72 (14.2%) patients died, 22 (4.3%) patients had an MI, and 91 (17.9%) patients had either event at a median follow-up of 2 (0.5-2.9) years. Noncompliance > or = 4 medications was significantly associated with adverse survival compared with compliant patients (29.7% vs 78.9%). After adjusting for traditional risk factors, The Global Registry of Acute Coronary Events risk score for predicting death during 6 months post-discharge, revascularization, left ventricular (LV) function, coronary artery disease (CAD) severity, and punctual clinic visits, noncompliance with > or = 4 evidence-based medications was an independent factor associated with death or MI (hazard ratio [HR], 2.83; 95% confidence interval [CI]=1.60-5.01) in this minority and uninsured population.

Rapid adoption of drug-eluting stents: Clinical practices and outcomes from the early drug-eluting stent era

OBJECTIVES We sought to evaluate the early drug-eluting stent (DES) era, characterized by widespread device use. BACKGROUND Contemporary clinical practice incorporating more selective DES use can only be assessed by understanding the early DES era. METHODS All patients receiving DES during the first 3 waves of the Evaluation of Drug Eluting Stents and Ischemic Events (EVENT) Registry (2004-2006) were evaluated. The primary end point was a composite of death, myocardial infarction (MI), and urgent revascularization at discharge and death, MI, or target lesion revascularization (TLR) at 1 year. The composite end point at each time point was compared across waves. Multivariable logistic regression was used for in-hospital outcomes and multivariable Cox regression was used for 1-year end points. RESULTS Ninety-two percent of EVENT patients received at least one DES. One third of patients were treated for Acute Coronary Syndromes (ACS) (33.8%), and later waves included lower lesion complexity. Across waves there was more frequent clopidogrel loading, a decrease in heparin and an increase in bivalirudin use (all P < .01). The primary composite end point of in-hospital death, MI or urgent revascularization occurred in 7.2% of patients, and did not differ across waves. Despite remarkably high levels of routine DES usage, the composite end point of death, MI, or TLR at 1 year averaged 13.5% and did not differ across waves. After adjustment, no statistically significant effect of wave on composite bleeding (P = .068) as well as in-hospital TLR (P = .053) was noted. At 1 year, wave was associated with a lower likelihood of TLR in the adjusted model (HR 0.81, P = .03). CONCLUSIONS The high-adoption DES era was associated with favorable outcomes, decreasing bleeding rates and changes in antithrombotic approach.

Clinical outcomes of patients treated with the cutting balloon and Sr-90 β-irradiation for instent restenosis

BACKGROUND The cutting balloon (CB) is an emerging therapy for the treatment of instent restenosis (ISR), but its impact on the clinical outcomes of patients treated with intracoronary radiation therapy (IRT) with Sr-90 compared with conventional PTCA and IRT is not clearly defined. METHODS We compared the baseline demographics, angiographic characteristics and clinical outcomes of 102 consecutive patients with ISR treated either with CB+IRT (n=45) or with conventional PTCA+IRT (n=57). The combined endpoint was the occurrence of major adverse cardiac events (MACE), which was defined as a composite of death, myocardial infarction (MI) or target vessel revascularization (TVR) at 6 months. RESULTS The CB+IRT group had a shorter mean lesion length (14.3+/-6.5 vs. 21.1+/-15.7, P=.009), and greater utilization of glycoprotein IIb/IIIa inhibitors during the procedure (48.9% vs. 26.3%, P=.02) compared to the PTCA+IRT group. There were no significant differences in the baseline demographics, angiographic and procedural results, or subsequent MACE at 6 months between the two groups. CONCLUSION The strategy of CB+IRT using Sr-90 for ISR is associated with similar procedural and clinical outcomes compared to conventional PTCA+IRT. Further study is warranted to determine which patient subgroups would derive the most benefit from this approach.

Frequency of abrupt vessel closure and side branch occlusion after percutaneous coronary intervention in a 6.5-year period (1994 to 2000) at a single medical center

The aims of this study were to analyze the contemporary trends in the changing incidence of abrupt vessel closure (AVC) after percutaneous coronary intervention (PCI), to determine the impact of intracoronary stenting and glycoprotein IIb/IIIa inhibitors (GPIs) on complication rates and etiologies, and to determine the incidence of side branch occlusion (SBO) as the etiology of AVC in the stent era, complications occurring during 3,300 consecutive PCIs performed from April 1994 to December 2000 at a single referral institution. In this consecutive patient cohort of PCI cases collected over a 6.5-year period, AVC occurred in 103 of 3,300 cases (3.12%). Linear regression analysis over this time frame documented a steadily decreasing incidence of AVC from 5.9% in 1994 to 1.1% in 2000 (-0.76%/per year, 95% confidence interval -0.99 to 0.52, p <0.05). Analysis using Pearsons correlation showed that the decreasing incidence of AVC was inversely correlated with the increasing percentage of intracoronary stents placed over this time period (r = -0.94, p <0.001). Additionally, GPI use increased from 0% in 1995 to 36.0% in 2000 (p = 0.009). The absolute incidence of SBO of a major branch vessel remained relatively stable over this 6.5-year period. However, SBO appeared to be increasing as the etiology of AVC, and accounted for 9.0% of AVC in 1995 compared with 28.0% of AVC in 2000. This increasing trend of the percentage of SBO as the etiology of AVC appeared to correlate with the increased use of stents (r = 0.85, p = 0.015). Thus, the incidence of AVC steadily decreased over the 6.5-year time period, and was associated with the increased use of stents and GPIs; conversely, SBO accounted for an increasing percentage of AVC over this time period.