Low‐Dose Heparin for Elective Percutaneous Coronary Intervention

Objectives

We evaluated the safety and efficacy of low‐dose heparin (40 IU/kg) for elective percutaneous coronary intervention (PCI).

Background

Current guidelines recommend a 70–100 IU/kg bolus of heparin for elective PCI, but this dose may be associated with increased bleeding risk. Low‐dose heparin may have an advantage in this regard, but has not been well studied.

Methods

From January 2008 to October 2012, 300 patients underwent elective transfemoral PCI and were treated with an initial bolus of 40 IU/kg of heparin at the UCLA Medical Center. Dual antiplatelet therapy with clopidogrel and aspirin was administered prior to or just after diagnostic coronary angiography. The primary end‐point was the composite of cardiac death, myocardial infarction, urgent target vessel revascularization for ischemia, or major bleeding within 30 days after PCI.

Results

The mean activating clotting time was 233 ± 28 seconds. The primary end‐point occurred in 2.3%. The cardiac death rate was 0.3% but was not related to the PCI. The myocardial infarction rate was 1.3%. Urgent target vessel revascularization occurred in 1 patient (0.3%). The major bleeding rate was 0.3%. No stent thrombosis occurred.

Conclusion

Using a lower dose of heparin with dual antiplatelet therapy is safe and is associated with a low bleeding risk after transfemoral PCI while providing suppression of ischemic events. This may also represent a cost savings compared with other antithrombotic strategies. A randomized clinical trial comparing low‐dose heparin with bivalirudin in patients is required to determine the optimal anticoagulation strategy. (J Interven Cardiol 2014;27:58–62)

     

Coronary obstruction following transcatheter aortic valve‐in‐valve implantation for failed surgical bioprostheses

Transcatheter aortic valve implantation (TAVI) for failed surgical bioprostheses, or “valve‐in‐valve” implantation, is a therapeutic option for high‐risk patients. While coronary occlusion during TAVI for native aortic stenosis has been described, in the setting of valve‐in‐valve implantation the bioprsthetic posts may be protective against this complication. We describe the first two cases of coronary occlusion following valve‐in‐valve therapy, both occurring during treatment of degenerated Mitroflow bioprostheses. Aortic root anatomy, coronary ostial position, and the specifics of the bioprosthetic valve type need to be considered in assessing and preventing this rare complication. © 2011 Wiley‐Liss, Inc.     

Meaning of Low‐Density Lipoprotein‐Apheresis for Hypercholesterolemic Patients at High Risk for Recurrence of Coronary Heart Disease

Abstract: The goal of cholesterol‐lowering therapy in hypercholesterolemic patients at high risk for recurrence of coronary heart disease (CHD) is the prevention of acute coronary syndrome by stabilization of coronary atheromatous plaque. We often encounter patients in whom it is difficult to maintain the serum cholesterol level at a desirable level with dietary therapy and drug treatment, despite the development and use of statins. For secondary prevention in patients who are at high risk for the recurrence of CHD and whose cholesterol level cannot be controlled by drugs alone, low‐density lipoprotein (LDL)‐apheresis therapy, which involves removal of LDL through extracorporeal circulation, is now available. Many reports concerning improvement of vascular endothelial function, improvement of myocardial ischemia, regression of coronary atherosclerotic lesions, stabilization of coronary plaque, and reduction in the incidence of cardiac events as a result of LDL‐apheresis treatment have been published in various countries. We believe that LDL‐apheresis should be performed on hypercholesterolemic patients with existing CHD for whom diet and maximum cholesterol‐lowering drug therapies have been ineffective or not tolerated and whose LDL cholesterol level is 160 mg/dL or higher.     

DALI Low‐Density Lipoprotein Apheresis in Homozygous and Heterozygous Familial Hypercholesterolemic Patients Using Low‐Dose Citrate Anticoagulation

Abstract: The purpose of this study was to clarify the efficacy and safety of direct adsorption of lipoprotein low‐density lipoprotein apheresis (DALI LDL apheresis) in patients with severe homozygous and heterozygous familial hypercholesterolemia who showed minor adverse effects during treatment with the usual DALI configuration (AC 1:20) through the use of a new system with low‐dose citrate anticoagulation (AC 1:40) developed in order to minimize citrate‐related adverse effects. Serum total cholesterol and LDL‐cholesterol (LDL‐C) showed a decrease of 57% to 61%, and 62 % to 67%, respectively, in the 2 patients. Serum lipoprotein (a) (Lp[a]) was higher in the homozygous patient (Patient 1: MD) and within the normal range in the heterozygous patient (Patient 2: ES). In the former, Lp(a) was reduced by 52%. Serum high‐density lipoprotein cholesterol (HDL‐C) showed a statistically insignificant acute reduction: 15% to 19%. The observed reduction is mainly related to the well‐known effect of hemodilution. The cardiovascular risk (total cholesterol/HDL‐C) was reduced in both patients (46% to 54%) as expected. Serum triglycerides were reduced by 33% to 49%. The mean blood volume processed per session was 7,600 ml. Fifteen treatments for each patient have successfully been completed without the appearance of any clinically significant subjective and objective symptoms related to treatment with the new system.     

Elevated Serum Cardiac Troponin in Non‐acute Coronary Syndrome

Cardiac troponins (CTn) are the most sensitive and specific biochemical markers of myocardial injury and risk stratification. The assay for troponin T (cTnI) is standardized, and results obtained from different institutions are comparable. This is not the case with troponin I (cTnT), and clinicians should be aware that each institution must analyze and standardize its own results. Elevated cTn levels indicate cardiac injury, but do not define the mechanical injury. The differentiation of cTn elevation caused by coronary events from those not related to an acute coronary syndrome (ACS) is tiresome, at times vexing, and often costly. Elevation of cTn in non‐ACS is a marker of increased cardiac and all‐cause morbidity and mortality. The cause of these elevations may involve serious medical conditions that require meticulous diagnostic evaluation and aggressive therapy. At present, there are no guidelines to treat patients with elevated troponin levels and no coronary disease. The current strategy of treatment of patients with elevated troponin and non‐ACS involves treating the underlying causes. Copyright © 2009 Wiley Periodicals, Inc.     

P‐Wave Signal‐Averaged Electrocardiogram Predicts Atrial Fibrillation After Coronary Artery Bypass Grafting

Background: AF is one of the most common complications after CABG. The aim of the study was to identify the risk factors for postoperative AF. Methods: Between June and December 2000, 129 consecutive patients (72 men, 47 women; mean age 67 ± 6 years) underwent preoperative signal‐averaged electrocardiogram (SAECG) with assessment of filtered P‐wave duration (fPWD) and of the root mean square voltage of the last 10 and 20 ms of atrial depolarization (RMSV10 and RMSV20, respectively) before CABG. Results: Fifty‐six (43%) patients developed one episode of AF lasting > 30 seconds at a mean distance of 2.6 ± 1.8 days after surgery (group A), while 73 patients remained in sinus rhythm (group B). No differences between the two groups were found in terms of age, sex, P‐wave duration on the standard ECG, left atrial dimensions, and operative characteristics. In contrast, group A patients showed a significantly longer fPWD (138 ± 10 vs 111 ± 9 ms; P < 0.001) and smaller RMSV10 and RMSV20 (2.8 ± 1.0 vs 4.3 ± 1.1 μV, P < 0.001; 4.2 ± 2.1 vs 6.2 ± 2.0 μV, P < 0.001). Multivariate analysis indicated only fPWD as an independent predictor of AF (P = 0.009). With a cut‐off value of 135 ms for fPWD, the occurrence of AF could be predicted with a sensitivity of 84%, a specificity of 73%, a negative predictive value of 85%, and a positive predictive value of 70%. Conclusion: Preoperative SAECG is a simple exam that correctly identifies patients at higher risk of AF after CABG. A more widespread use of this technique can be suggested. A.N.E. 2002;7(3):198–203     

Prognostic Value of Continuous ST‐Segment Monitoring in Patients with Non‐ST‐Segment Elevation Acute Coronary Syndromes

Background: Patients with non‐ST‐segment elevation acute coronary syndromes constitute a heterogeneous group concerning prognosis. The 12‐lead ECG at rest is recommended for early risk stratification but is unable to reflect the dynamic nature of myocardial ischemia and coronary thrombosis. This study investigated whether continuous ST‐segment monitoring provides early prognostic information in such patients. Methods: We prospectively studied 183 patients admitted due to chest pain at rest suggestive of an acute coronary syndrome. ST‐segment monitoring was performed continuously for 24 hours from admission. Cardiac‐specific troponin I levels were determined on admission and every 6 hours for the first 24 hours. The endpoint was defined as death or nonfatal myocardial infarction, whichever occurred first by 30 days follow‐up. Results: ST episodes, defined as transient ST deviations of at least 0.1 mV, were detected in 50 patients 27.3%) and associated with worse 30‐day outcome: 22.0% endpoint rate compared to 6.8% for patients without ST episodes (P = 0.003). In a multivariate analysis, the presence of ST episodes hazard ratio, 3.07; 95% Cl, 1.26 to 7.46; P = 0.014) and peak troponin I levels > 0.2 μg/L (hazard ratio, 2.65; 95% Cl, 1.01 to 6.95; P = 0.048) were independent predictors of prognosis. The combination of ST‐segment monitoring and peak troponin I identified patients at low (2.5%, n = 79), intermediate (14.5%, n = 76), and high (25.0%, n = 28) risk for the 30‐day endpoint. Conclusions: In patients with non‐ST‐segment elevation acute coronary syndromes, continuous ST‐segment monitoring provides on‐line early prognostic information, in addition to troponin I levels. A.N.E. 2002;7(1):29–39