Francis Q. Almeda

Predictors of late cardiac events following treatment with Sr-90 β-irradiation for instent restenosis

BACKGROUND Intracoronary radiation therapy (IRT) with Sr-90 using the Novoste Beta-Cath system has been shown to be an effective therapy for instent restenosis (ISR), but the temporal occurrence of cardiac events and the predictors of late complications require further investigation. METHODS We analyzed the demographics, lesion characteristics and clinical outcomes of 138 consecutive patients with ISR treated with IRT from September 1998 to March 2002. Major adverse cardiac events (MACE) were defined as death, myocardial infarction (MI) or target vessel revascularization (TVR). Characteristics of early (< or =8 months) and late (>8 months) failures were analyzed. RESULTS Thirty-two (23.1%) of 138 patients had MACE on follow-up; 25% (8/32) of failures occurred late after treatment with IRT. A comparison of the clinical and angiographic profile of early and late failures using univariate analysis indicates no correlations to late failure following IRT. Duration to failure after IRT was 14.25+/-3.69 months in the late group compared to 4.63+/-2.86 months in the early group (P<.001). CONCLUSIONS Late MACE after IRT with Sr-90 for ISR occur beyond the traditional period for clinical restenosis in 25% of cases and are difficult to predict. Further study is warranted to identify patients at risk for the development of late complications after IRT.

Pulmonic valvular stenosis in adults: Diagnosis and treatment

Pulmonic valvular stenosis, a relatively common congenital disorder, is being increasingly diagnosed in olderage groups. Young adults may present with dyspnea, lightheadedness, or exertional syncope. Treatment with balloon valvuloplasty is technically feasible and has been associated with durable results. We present a case of a young patient with hemodynamically significant pulmonic valvular stenosis and discuss the pathophysiology, diagnosis, and treatment of this condition.

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.

Alternative therapeutic strategies for patients with severe end-stage coronary artery disease not amenable to conventional revascularization

Although there have been remarkable advances in medical therapy, percutaneous coronary interventions, and coronary artery bypass graft surgery, complete revascularization remains a challenge given the more complex coronary artery disease prevalent in contemporary practice. The lack of donors for cardiac transplantation will fuel the search for effective alternative strategies for dealing with patients with severe ischemic heart disease not amenable to conventional revascularization techniques. Percutaneous laser revascularization clearly diminishes anginal symptoms; however, the blinded trials have provided conflicting results, with one study showing a definite decrease in angina and another suggesting that the placebo effect may play a major role in this modality. Similarly, surgical transmyocardial laser revascularization is limited by the lack of consistent improvement in objective measurements of ischemia and the potential confounding mechanisms of denervation and the placebo effect, and thus should be reserved for only the most highly selected patients. Although enhanced external counterpulsation is associated with an improvement in anginal symptoms and exercise tolerance, this modality is limited by its availability, tolerability, and rigid exclusion criteria. Of the alternative strategies available, therapeutic angiogenesis holds the most promise. However, the long‐term results of ongoing randomized clinical trials require further scrutiny. Novel methods for vascular reconstruction are evolving techniques, but should be viewed currently as mainly experimental methods. The common goals of these new treatment options would be to reduce symptoms, decrease morbidity, and potentially improve mortality by reducing ischemia through favorably impacting myocardial oxygen supply and demand. The optimal management of patients with severe end‐stage coronary artery disease not amenable to conventional revascularization techniques will continue to remain a challenge for the clinician and will be the main focus of basic cardiovascular research and clinical trials in the new millennium. Catheter Cardiovasc Interv 2003;60:57–66.

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.

The Contemporary Management of Acute Myocardial Infarction

The contemporary management of acute myocardial infarction continues to evolve rapidly. The ultimate goal of therapy is timely, complete, and sustained myocardial reperfusion. There is a powerful time-dependent effect on mortality, and thus the balance between the time and likelihood of maximal reperfusion is crucial in deciding whether to use primary percutaneous balloon angioplasty or thrombolysis as the initial reperfusion strategy. Newer thrombolytic agents allow for equivalent coronary reperfusion compared with the standard accelerated alteplase (tPA) regimen with the advantage of easier dosing regimens. Low molecular weight heparin has been shown to be superior to unfractionated heparin and likely will be the standard of care in the near future. The use of glycoprotein IIb/IIIa inhibitors has been shown to decrease the short- and long-term complication rates in patients with acute coronary syndromes treated medically and with percutaneous coronary interventions; however, the choice of the optimal agent and dosing regimen in various clinical settings remains controversial. Combination therapy with low-dose fibrinolytics, glycoprotein IIb/IIIa inhibitors, and low molecular weight heparin, with or without subsequent early planned percutaneous coronary interventions, may provide the optimal strategy for maximal coronary reperfusion, but the results of large, randomized mortality trials currently underway need to be analyzed. Risk stratification will continue to play a major role in determining which patients should receive a specific therapy. The care of the patient with an acute myocardial infarction will continue to be a challenge requiring the proper selection from the vast pharmaceutic and interventional options available.

CORONARY REVASCULARIZATION IN MULTIVESSEL DISEASE Which is better, stents or surgery? Findings to date on important, practical differences between percutaneous coronary intervention and coronary artery bypass grafting.

Coronary artery disease (CAD) remains the major cardiovascular health issue in contemporary clinical practice. Treatment options for multivessel CAD include medical therapy, percutaneous coronary intervention (PCI), and coronary artery bypass grafting (CABG). Here, the authors review the most recent data that compare intracoronary stenting to CABG in multivessel disease. They address therapeutic issues surrounding proper selection of the optimal revascularization strategy and give special consideration to high-risk populations, such as patients with diabetes.

Troponin T in acute coronary syndromes: mechanisms and management issues

We read with great interest the article in JACC by Lindahl et al. [(1)][1]titled “Mechanisms Behind the Prognostic Value of Troponin T in Unstable Coronary Artery Disease: A FRISC II Substudy.” There is limited data on the coronary anatomy of patients with acute coronary syndromes and an

Noncardiac applications of glycoprotein IIb/IIIa inhibitors.

Platelet activation and aggregation have become increasingly recognized as the primary processes involved in the cascade that leads to thrombus formation in atherosclerotic vascular disease. Glycoprotein IIb/IIIa receptor inhibitors (GPI) favorably impact thrombus formation and distal embolization by inhibiting the final common pathway of platelet aggregation. Glycoprotein IIb/IIIa inhibitors have been used effectively in a wide variety of clinical scenarios including unstable angina, non‐ST segment elevation myocardial infarction, ST segment elevation myocardial infarction, and low and high risk percutaneous coronary interventions with and without intracoronary stenting, however there is limited data regarding the use of these potent antiplatelet agents in the setting of extracardiac vascular disease. This article will review the non‐cardiac applications of glycoprotein IIb/IIIa inhibitors in the setting of acute ischemic stroke, carotid and vertebral angioplasty and stenting, acute critical limb ischemia, and percutaneous interventions in peripheral arterial occlusive disease. Catheter Cardiovasc Interv 2004;62:530–538.

Mechanisms behind intracoronary radiation therapy failure

We read with great interest the study by Ajani et al., “The Outcome of Percutaneous Coronary Intervention in Patients With In-Stent Restenosis Who Failed Intracoronary Radiation Therapy” [(1)][1]. Limited data are available on the outcomes of patients with in-stent restenosis (ISR) who undergo