Impact of Drug-Eluting Stents on Clinical Outcomes in Patients With Diffuse Coronary Lesions

BACKGROUND AND OBJECTIVES: In the era of stents, lesion length remains an important predictor of restenosis. Drug-eluting stents (DESs) have significantly reduced in-stent restenosis (ISR), but results in long lesions are still lacking. Therefore, we investigated the impact of DESs on clinical outcomes in patients with diffuse coronary lesions. SUBJECTS AND METHODS: Between January 2004 and January 2005, 80 patients (94 lesions) with lesions >20 mm in length were treated with one or more DESs and underwent follow-up coronary angiography. The patients were divided into three groups: Group 1 was composed of those with lesions 21 to 35 mm in length, Group 2 was composed of those with lesions 36 to 50 mm in length, and Group 3 was composed of those with lesions > or =51 mm in length. RESULTS: The mean clinical follow-up duration was 9 months. On the 6-month follow-up angiogram, 6.4% of the lesions had binary ISR (5.0% in group 1, 8.7% in group 2, and 9.1% in group 3). The percent diameter stenosis was 6.0+/-18.15% in Group 1, 12.61+/-21.99% in Group 2, and 19.81+/-31.26% in Group 3(p< 0.05). Late lumen loss was 0.17+/-0.50 mm in Group 1, 0.39+/-0.66 mm in Group 2, and 0.59+/-0.93 mm in Group 3 (p<0.05). Lesion length was associated with an increase in percent diameter stenosis and late lumen loss (of 6.9% and 0.21 mm per 15 mm). CONCLUSION: DES implantation is considered safe and effective in the treatment of diffuse lesions. However, lesion length may be associated with an increase in percent diameter stenosis and late lumen loss at 6-month follow-up.

Very Late Stent Thrombosis in Coronary Bare-Metal Stent Implantation: A Case Report

Stent thrombosis is generally a fatal complication after percutaneous coronary intervention. Despite the incidence of stent thrombosis has reduced with improved techniques and drugs, stent thrombosis persists at a rate of 0.5-2% in elective cases, and up to 6% in patients with acute coronary syndromes. It almost always causes acute myocardial infarction or sudden cardiac death. While very late stent thrombosis, occurring beyond 1 year, is not uncommon with the use of drug-eluting stents, it is distinctly unusual with the use of bare-metal stents. We report a case of very late thrombosis of a bare-metal stent occurring 880 days after coronary stent implantation.

A Comparison of Tissue Doppler Echocardiography and B-Type Natriuretic Peptide in Estimating Pulmonary Capillary Wedge Pressure

BACKGROUND: There are several echocardiographic parameters, such as early transmitral velocity/tissue Doppler mitral annular early diastolic velocity(E/Ea) or deceleration time, reported to be reliable indices to estimate pulmonary capillary wedge pressure(PCWP). Recently, B-type natriuretic peptide(BNP) level is also reported to increase in accordance with increased left ventricular filling pressure in systolic or diastolic heart failure. This study was performed to compare E/Ea and BNP for the ability to estimate PCWP. METHODS: Several echocardiographic Doppler parameters including especially E/Ea were obtained from transthoracic Doppler echocardiography. Simultaneously, serum BNP level and PCWP estimated by using Swan-Ganz catheter were obtained, respectively. RESULTS: E/Ea revealed a correlation of r=0.88 (p or =11 was the optimal cutoff to predict PCWP > or =15 mmHg (sensitivity, 94%; specificity, 90%), whereas the optimal BNP cutoff was > or =250 pg/mL (sensitivity, 52%; specificity, 74%). CONCLUSION: Mitral E/Ea has a better correlation with PCWP than BNP. Mitral E/Ea appears more sensitive and specific than BNP for PCWP > or =15 mmHg in cardiac patients.

Angioplasty with Stenting after Arterial Switch Operation in 7-Year-Old Child

We present the case of a 7 year-old child who underwent angioplasty with a stent for anastomosis site stenosis between a left subclavian artery free graft and the left main coronary artery in an arterial switch operation.

Causes of elevated cardiac troponin I in patients with normal coronary angiogram / 대한내과학회지

BACKGROUND: Cardiac troponin I (cTnI) is most recently described and has nearly absolute myocardial tissue specificity, as well as high sensitivity. But an increased value for cTnI that indicates myocardial injury is not always synonym of myocardial infarction or ischemia due to coronary artery disease. METHODS: Retrospective follow-up study for whom underwent coronary angiography for suspected coronary artery disease was done if they had an elevated cTnI value and angiographically normal or minimal disease. RESULTS: 33 patients were qualified. Cut-off value for elevated cTnI was 0.06 ng/mL. Increased cTnI values were attributed to severe congestive heart failure in 7 patients, variant angina in 7 patients, myocarditis in 5 patients, pericarditis in 1 patient, severe myocardial bridge in 1 patient, rhabdomyolysis in 1 patient and cerebral infarction in 1 patient. Tachycardia was precipitating cause in 4 patients (sinus tachycardia, paroxysmal supraventricular tachycardia, paroxysmal atrial fibrillation and sustained ventricular tachycardia for each), two of whom had hemodynamic compromise. 2 of 33 patients had no identifiable cause for a rise in cTnI value. There was no acute myocardial infarction at 42+/-34 weeks follow-up. CONCLUSIONS: Although cTnI is a sensitive and specific marker of myocardial injury, an elevation of cTnI value may have a cause other than myocardial infarction or ischemia and may occur without significant angiographic coronary artery disease.

In vivo targeting of ERGpotassiumchannels inmice and dogs by a positron-emitting analogue of fluoroclofilium

The antiarrhythmic clofilium is an efficient blocker of hERG1 potassium channels that are strongly expressed in the heart. Therefore, derivatives of clofilium that emit positrons might be useful tools for monitoring hERG1 channels in vivo. Fluoroclofilium (F-clofilium) was synthesized and its channel-blocking properties were determined for hERG1 and hEAG1 channels expressed in HEK 293 cells and in Xenopus oocytes. When applied extracellularly in the whole-cell patch-clamp configuration, F-cloflium exhibited a slower onset of block when compared with clofilium, presumably owing to its lower membrane permeability. When applied in the inside-out configuration at the intracellular membrane side, it blocked hEAG1 channels almost as efficiently as clofilium (IC50 1.37 nM and 0.83 nM, respectively). Similar results were obtained for hERG1, showing Fclofilium is a potent hERG1 and hEAG1 channel blocker once it has reached the intracellularly accessible target site at the channel. Using the 18Flabeled analog we studied the in vivo binding and distribution of F-clofilium in mice and a dog. Greatest activity was found in kidneys and bones. A small but significant enrichment of activity in the dog myocardium known for its expression of cERG1 channels allowed to depict the myocardium of a living dog by PET. Thus, F-clofilium is a useful tool for imaging hERG channels in living organisms.

Changes in the Sympathetic Activity after Percutaneous Mitral Balloon Valvuloplasty in Patients with Rheumatic Mitral Stenosis

BACKGROUND AND OBJECTIVES: As mitral stenosis worsens, the cardiac output can be reduced, with a compensatory increase in the sympathetic nervous activity. An accelerated sympathetic nervous activity is responsible for various pathophysiological changes, including atrial thrombus formation, pulmonary congestion and myocardial ischemia. In this study, the sympathetic nervous activity was evaluated in patients with rheumatic mitral valvular stenosis, both before and after a percutaneous mitral balloon valvuloplasty (PMV). SUBJECTS AND METHODS: A PMV was successfully performed in 19 patients with mitral stenosis. The hemodynamic data were obtained by Swan-Ganz catheterization, and the variability in the heart rate evaluated by time domain measure via 24-hour ECG monitoring. An exercise test was performed according to Chung's exercise protocol, with the plasma norepinephrine level obtained before, during and after exercise. RESULTS: After the PMV, the right ventricle systolic, mean pulmonary arterial, pulmonary capillary wedge and left atrial pressures were significantly decreased. However, there were no significant changes in the right atrial, right ventricle end-diastolic and left ventricle end-diastolic pressures. After the PMV, the plasma norepinephrine level, an indicator of the sympathetic activity, was significantly decreased. On the other hand, the variability in heart rate, indicator of parasympathetic activity, was significantly decreased. CONCLUSION: In patients with mitral valvular stenosis, the sympathetic activity is accelerated, while the parasympathetic activity is decreased. This situation can be immediately reversed after a successful PMV.

Heart Rate Variability in Inappropriate Sinus

BACKGROUND: Inappropriate sinus tachycardia(IST) manifests chronic nonparoxysmal sinus tachycardia in healthy individuals and is characterized by consistently elevated heart rate and exaggerated responses to minimal physical activity. Heart rate variability(HRV) using 24-hour Holter monitoring represents one of the methods of evaluating the harmony of autonomic nervous system activity. So, authors investigate the autonomic nervous system activity by the HRV in patients with IST. METHODS: We compared the pattern of cardiac sympathetic and parasympathetic activity through the time domain analysis of heart rate variability with 24-hour Holter monitoring between 23 patients with IST and 23 healthy control subjects. None of the patients had organic heart disease as determined by routine laboratory examination and echocardiography. And then, time domain measures(mean NN, SDNN, SDANN, SD, rMSSD, pNN50) were analyzed. RESULTS: The mean age of patients and control were 38+/-10 and 37 9 years, respectively(p=S). The mean clinical heart rate of patients and control was 104 5/min and 72+/-5/min, respectively(p<0.05). Among the time domain indices, mean of all normal RR intervals(mean NN), standard deviation of all normal RR intervals(SDNN), standard deviation of mean RR interval(SDANN), mean of standard deviations of all normal RR intervals(SD), root mean square successive differences between adjacent normal RR intervals(rMSSD), and percent of difference between adjacent normal RR intervals(pNN50) in the patient group were significantly shorter compared to control group(p<0.01). CONCLUSION: In IST, cardiac vagal influence on the heart rate is blunted.