Craig R. Narins

Relation Between Activated Clotting Time During Angioplasty and Abrupt Closure

BACKGROUND The purpose of this study was to determine whether the degree of heparin anticoagulation during coronary angioplasty, as measured by the activated clotting time, is related to the risk of abrupt vessel closure. METHODS AND RESULTS Sixty-two cases of in- and out-of-laboratory abrupt closure in patients in whom intraprocedure activated clotting times were measured were identified from a population of 1290 consecutive patients who underwent non-emergency coronary angioplasty. This group was compared with a matched control population of 124 patients who did not experience abrupt closure. Relative to the control population, patients who experienced abrupt closure had significantly lower initial (median, 350 seconds [25th to 75th percentile, 309 to 401 seconds] versus 380 seconds [335 to 423 seconds], P = .004) and minimum (345 seconds [287 to 387 seconds] versus 370 seconds [321 to 417 seconds], P = .014) activated clotting times. Higher activated clotting times were not associated with an increased likelihood of major bleeding complications. Within this population, a strong inverse linear relation existed between the activated clotting time and the probability of abrupt closure. CONCLUSIONS This study demonstrates a significant inverse relation between the degree of anticoagulation during angioplasty and the risk of abrupt closure. A minimum target activated clotting time could not be identified; rather, the higher the intensity of anticoagulation, the lower the risk of abrupt closure.

Myocardial Infarction After Carotid Stenting and Endarterectomy Results From the Carotid Revascularization Endarterectomy Versus Stenting Trial

Background— The Carotid Revascularization Endarterectomy Versus Stenting Trial (CREST) found a higher risk of stroke after carotid artery stenting and a higher risk of myocardial infarction (MI) after carotid endarterectomy. Methods and Results— Cardiac biomarkers and ECGs were performed before and 6 to 8 hours after either procedure and if there was clinical evidence of ischemia. In CREST, MI was defined as biomarker elevation plus either chest pain or ECG evidence of ischemia. An additional category of biomarker elevation with neither chest pain nor ECG abnormality was prespecified (biomarker+ only). Crude mortality and risk-adjusted mortality for MI and biomarker+ only were assessed during follow-up. Among 2502 patients, 14 MIs occurred in carotid artery stenting and 28 MIs in carotid endarterectomy (hazard ratio, 0.50; 95% confidence interval, 0.26 to 0.94; P =0.032) with a median biomarker ratio of 40 times the upper limit of normal. An additional 8 carotid artery stenting and 12 carotid endarterectomy patients had biomarker+ only (hazard ratio, 0.66; 95% confidence interval, 0.27 to 1.61; P =0.36), and their median biomarker ratio was 14 times the upper limit of normal. Compared with patients without biomarker elevation, mortality was higher over 4 years for those with MI (hazard ratio, 3.40; 95% confidence interval, 1.67 to 6.92) or biomarker+ only (hazard ratio, 3.57; 95% confidence interval, 1.46 to 8.68). After adjustment for baseline risk factors, both MI and biomarker+ only remained independently associated with increased mortality. Conclusions— In patients randomized to carotid endarterectomy versus carotid artery stenting, both MI and biomarker+ only were more common with carotid endarterectomy. Although the levels of biomarker elevation were modest, both events were independently associated with increased future mortality and remain an important consideration in choosing the mode of carotid revascularization or medical therapy. Clinical Trial Registration— URL: . Unique identifier: [NCT00004732][1]. # Clinical Perspective {#article-title-38} [1]: /lookup/external-ref?link_type=CLINTRIALGOV&access_num=NCT00004732&atom=%2Fcirculationaha%2F123%2F22%2F2571.atomBackground— The Carotid Revascularization Endarterectomy Versus Stenting Trial (CREST) found a higher risk of stroke after carotid artery stenting and a higher risk of myocardial infarction (MI) after carotid endarterectomy. Methods and Results— Cardiac biomarkers and ECGs were performed before and 6 to 8 hours after either procedure and if there was clinical evidence of ischemia. In CREST, MI was defined as biomarker elevation plus either chest pain or ECG evidence of ischemia. An additional category of biomarker elevation with neither chest pain nor ECG abnormality was prespecified (biomarker+ only). Crude mortality and risk-adjusted mortality for MI and biomarker+ only were assessed during follow-up. Among 2502 patients, 14 MIs occurred in carotid artery stenting and 28 MIs in carotid endarterectomy (hazard ratio, 0.50; 95% confidence interval, 0.26 to 0.94; P=0.032) with a median biomarker ratio of 40 times the upper limit of normal. An additional 8 carotid artery stenting and 12 carotid endarterectomy patients had biomarker+ only (hazard ratio, 0.66; 95% confidence interval, 0.27 to 1.61; P=0.36), and their median biomarker ratio was 14 times the upper limit of normal. Compared with patients without biomarker elevation, mortality was higher over 4 years for those with MI (hazard ratio, 3.40; 95% confidence interval, 1.67 to 6.92) or biomarker+ only (hazard ratio, 3.57; 95% confidence interval, 1.46 to 8.68). After adjustment for baseline risk factors, both MI and biomarker+ only remained independently associated with increased mortality. Conclusions— In patients randomized to carotid endarterectomy versus carotid artery stenting, both MI and biomarker+ only were more common with carotid endarterectomy. Although the levels of biomarker elevation were modest, both events were independently associated with increased future mortality and remain an important consideration in choosing the mode of carotid revascularization or medical therapy. Clinical Trial Registration— URL: http://www.ClinicalTrials.gov. Unique identifier: NCT00004732.

A Call for Provisional Stenting The Balloon Is Back

During the past 20 years, the equipment used to perform percutaneous coronary revascularization has undergone a dramatic transformation from simple balloon dilatation catheters to sophisticated mechanical devices and endoprostheses. The impetus for this evolution in technology was initially a byproduct of suboptimal immediate and long-term results obtained with standard balloon angioplasty. New techniques, including directional and rotational atherectomy, have resulted in improved procedural success rates, especially for more complex lesion subtypes, although their ability to curtail restenosis remains controversial.1 2 Intracoronary stents have had a dramatic impact on reduction of the incidence of acute complications after failed balloon angioplasty and represent the only currently available strategy shown to limit both clinical and angiographic restenosis.3 4 5 6 7 8 9 10 11 12 Based on these advantages, stent implantation is used in approximately half of all percutaneous interventions in the United States. However, despite their proven benefits, coronary stents continue to be accompanied by several theoretical and practical limitations: they are costly, typically associated with a more marked degree of neointimal formation than balloon angioplasty, and difficult to use with some lesion subsets such as bifurcation stenoses, and they have engendered the new and difficult-to-treat entity of in-stent restenosis. Although the major focus in the field of interventional cardiology over the past decade has been on the development of new devices and adjunctive pharmacological therapies, the short- and long-term success rates after standard balloon angioplasty have improved significantly. Part of the improvement is likely a manifestation of enhanced operator experience and better equipment, but the results of balloon angioplasty have also benefited greatly from the availability of coronary stents for both “bailout” (for actual or threatened abrupt closure) or “backup” (for suboptimal balloon results) indications, potentially allowing a strategy of more aggressive balloon dilatation than could be safely …

Clinical Implications of Silent Versus Symptomatic Exercise-Induced Myocardial Ischemia in Patients With Stable Coronary Disease☆

OBJECTIVES This study was undertaken to better understand the functional and prognostic significance of silent relative to symptomatic ischemia. BACKGROUND Previous studies have reached conflicting conclusions as to whether painless ischemia identified during noninvasive cardiac testing is related to a lesser extent of myocardial ischemia or a different prognosis than ischemia accompanied by angina, or both. METHODS Nine hundred thirty-six clinically stable patients 1 to 6 months after an acute coronary event, either myocardial infarction or unstable angina, underwent ambulatory monitoring, exercise treadmill testing and stress thallium-201 scintigraphy. They were then followed up prospectively for a mean of 23 months for recurrent cardiac events (cardiac death, nonfatal myocardial infarction or unstable angina). RESULTS Compared with patients with symptomatic ischemia during testing (n = 125), those with silent ischemia (n = 378) demonstrated less severe and extensive reversible defects on stress thallium scintigraphy (p = 0.0008), less functional impairment during treadmill testing manifested by longer exercise duration (640 +/- 173 vs. 529 +/- 190 s, p = 0.002) and longer time to ST segment depression (530 +/- 215 vs. 419 +/- 205 s, p = 0.0001) and less frequent ST segment depression during ambulatory monitoring (9% vs. 19%, p = 0.005). Patients with symptomatic ischemia had a significantly (p = 0.004) increased number of subsequent recurrent cardiac events (28.8%) versus those with silent (18.0%) or no (17.3%) ischemia. Adverse outcomes were especially concentrated in the subgroup with symptomatic ischemia and poor exercise tolerance. The difference in cardiac event rates between patients with silent versus symptomatic ischemia persisted after adjustment for baseline clinical characteristics by Cox regression analysis. CONCLUSIONS Patients with painless ischemia during exercise testing 1 to 6 months after recovery from a coronary event have less jeopardized ischemic myocardium and fewer recurrent cardiac events than patients with symptomatic ischemia.

Problem of Angioplasty in Diabetics

Coronary artery bypass graft surgery improves survival for certain subsets of patients with coronary artery disease and has been accepted as the revascularization “gold standard” since the 1970s. PTCA, introduced by Gruentzig in 1977, was initially envisioned as a potentially serial treatment for patients with focal coronary artery disease to prevent the development of complex disease severe enough to require CABG. By the mid-1980s, however, expertise and technology had improved to the point that PTCA could, apparently with reasonable success and safety, be brought to bear on anatomic situations previously considered to be solely the realm of the cardiovascular surgeon. To ascertain whether PTCA for patients with moderately advanced disease was truly an appropriate alternative to CABG, several RCTs were undertaken. At the time, it appeared that both revascularization alternatives were sufficiently mature that the long-term results would be relevant when they became available 5 to 10 years later. In aggregate, 4310 patients with multivessel disease thought to be suitable for either form of revascularization (thereby excluding many patients with far advanced disease) were enrolled in six RCTs between 1986 and 1991. The overall trial results were remarkably concordant. CABG was associated with a slight but not statistically significant survival advantage, less angina, and far fewer later revascularizations. PTCA led to a slight but insignificant reduction in myocardial infarction over the ensuing 2 to 5 years.1 2 3 4 5 6 Critics of RCTs often contest the generalizability of the treatment outcomes reported. They question whether it might be an oversimplification to apply the overall results of a trial both to all of its component patients and also to all similar but nonrandomized patients. In fact, given the general homogeneity engendered by the focus of most clinical trials, it is unusual for some patients to benefit and others to …

The relationship between periprocedural myocardial infarction and subsequent target vessel revascularization following percutaneous coronary revascularization: Insights from the EPIC trial☆

OBJECTIVES We sought to determine whether periprocedural myocardial infarction complicating percutaneous coronary revascularization is associated with subsequent clinical restenosis, as judged by the need for target vessel revascularization. BACKGROUND Although myocardial enzyme elevation following angioplasty is associated with increased late mortality, its effect on subsequent clinical restenosis, as assessed by the need for late target vessel revascularization (TVR), is unknown. METHODS Serial myocardial enzyme determinations were performed on 2,099 patients who underwent angioplasty or atherectomy in the Evaluation of IIb/IIIa platelet receptor antagonist 7E3 in Preventing Ischemic Complications (EPIC) trial. Thirty-day survivors were prospectively followed for three years for adverse clinical events including death and need for TVR. RESULTS Within the study population, periprocedural creatine kinase (CK) elevation was a predictor of late mortality. Among patients with elevated CK, however, a paradoxical decrease in the need for late TVR was present. This relationship became progressively more profound as the magnitude of CK release increased. Late TVR occurred in 29.8% of patients with no CK elevation, 24.8% with CK elevation to >3 times normal, and 16.9% with >10 times elevation (hazard ratio 0.51, 95% CI 0.29, 0.91). CONCLUSIONS In the EPIC study, patients with periprocedural MI were less likely to develop clinical restenosis as measured by the need for TVR. Mechanistically, although it is unlikely that CK elevation prevents vascular renarrowing per se, myocardial necrosis impairs the clinical manifestation of restenosis, thereby reducing the need for ischemia-driven TVR. This novel finding 1) highlights the potential discordance between angiographic and clinical measures of restenosis, and 2) has implications for clinical trials, as therapies that reduce periprocedural MI may be associated with a perceived excess of restenosis when measured by the need for TVR.

Drug-eluting stent implantation for treatment of recurrent renal artery in-stent restenosis

Percutaneous renal artery stenting has become the treatment of choice for renal artery stenosis. In‐stent restenosis (ISR) still remains a persistent problem. Drug eluting stents have significantly reduced the incidence of ISR in coronary arteries. We report a case in which recurrent renal ISR was successfully treated with paclitaxel‐eluting stent implantation, using intravascular ultrasound guidance, with maintained stent patency at 6 months.

Inferior Vena Cava Thrombosis.

Thrombosis of the inferior vena cava (IVC) is an under-recognized entity that is associated with significant short- and long-term morbidity and mortality. In absence of a congenital anomaly, the most common cause of IVC thrombosis is the presence of an unretrieved IVC filter. Due to the substantial increase in the number of IVC filters placed in the United States and the very low filter retrieval rates, clinicians are faced with a very large population of patients at risk for developing IVC thrombosis. Nevertheless, there is a paucity of data and societal guidelines with regards to the diagnosis and management of IVC thrombosis. This paper aims to enhance the awareness of this uncommon, but morbid, condition by providing a concise, yet comprehensive, review of the etiology, diagnostic approaches, and treatment strategies in patients with IVC thrombosis.

Time dependence of life-threatening ventricular tachyarrhythmias after coronary revascularization in MADIT-CRT

BACKGROUND Coronary revascularization (CR) may confer electrical stability in patients with ischemic cardiomyopathy. However, data regarding the effect of CR on the development of ventricular tachyarrhythmias in this population are limited. OBJECTIVE The purpose of this study was to evaluate the association between CR and arrhythmic risk in postmyocardial infarction (post-MI) patients with left ventricular dysfunction. METHODS The risk for life-threatening ventricular tachyarrhythmias (defined as a first appropriate defibrillator therapy for ventricular tachycardia [VT]/ventricular fibrillation [VF] or death) was compared between post-MI patients with and those without prior CR (n = 612 and 147, respectively) enrolled in the Multicenter Automatic Defibrillator Implantation Trial-Cardiac Resynchronization Therapy (MADIT-CRT). RESULTS The 3-year cumulative rate of VT/VF or death was significantly higher among patients without prior CR (42%) than in patients who underwent prior CR (32%, P = .02). Multivariate analysis demonstrated that patients without prior CR had 48% increased risk (P = .01) for VT/VF or death. Risk reduction associated with CR was related to elapsed time from CR, assessed both as a categorical variable (tertiles for time from CR: ≥7 years, hazard ratio [HR] = 1.93, P = .001; 1.5-7 years, HR = 1.70, P = .01 vs <1.5 years) and as a continuous measure (4%, P = .002, increased risk for VT/VF or death per 1-year increment of elapsed time from CR). The effect of CR on arrhythmic risk was similar in patients treated with a defibrillator alone or when combined with cardiac resynchronization therapy. CONCLUSION Post-MI patients with left ventricular dysfunction who undergo CR experience a time-dependent reduction in the risk for subsequent life-threatening ventricular tachyarrhythmias.

Randomized controlled trial of topical hemostasis pad use for achieving vascular hemostasis following percutaneous coronary intervention.

Objectives: We conducted a randomized trial to determine the efficacy of two topical hemostasis pads in promoting vascular hemostasis following PCI, and to assess the appropriate level of anticoagulation for sheath removal. Background: Pads coated with procoagulant materials are widely marketed and used to augment vascular hemostasis following PCI, yet clinical effectiveness and safety data are lacking. Methods: 184 patients who underwent PCI using the femoral approach were randomized to one of four methods of sheath removal: (1) at ACT < 250 using the Chito‐Seal™ pad; (2) at ACT < 250 using the Clo‐Sur PAD™; (3) at ACT < 250 using manual compression alone; (4) at ACT < 170 using manual compression alone. Results: Time to hemostasis was significantly shorter in the hemostasis pad groups compared to the conventional compression groups (16.2 ± 4.9, 16.0 ± 5.3, 19.3 ± 7.8, and 18.3 ± 5.7 min, respectively, P = 0.027), however overall bed rest times following intervention were not reduced by use of either hemostasis pad. The incidence of major or minor bleeding complications did not differ among groups. Irrespective of hemostasis pad use, removal of sheaths at higher ACT levels allowed shorter time to ambulation following PCI without an increase in bleeding events. Conclusions: The hemostasis pads tested shortened time to hemostasis compared to standard manual compression, although the absolute reduction in time to hemostasis was relatively small and did not translate into a reduction in overall bed rest time. Independent of hemostasis pad use, removal of arterial sheaths at higher than conventional activated clotting times was safe and resulted in significant reductions in time to ambulation.