Clinical Outcomes Following Percutaneous Coronary Intervention With Drug‐Eluting Stents Versus Bare Metal Stents in Patients on Chronic Hemodialysis

Background

Patients on chronic hemodialysis (HD) are recognized as a high‐risk group for adverse events after percutaneous coronary intervention, and whether drug‐eluting stents (DES) are associated with improved outcomes over bare metal stents (BMS) is still uncertain. The purpose of this study was to assess the efficacy of DES compared with BMS at short‐ and long‐term follow‐up (FU) in an unselected sample of HD patients.

Methods and Results

In the time period 2005–2010, consecutive patients on chronic HD treated with percutaneous coronary intervention (PCI) and stent implantation were retrospectively selected and analyzed. A total of 169 patients were selected, 77 treated exclusively with BMS and 92 exclusively with DES. Baseline clinical characteristics were similar in the 2 groups as well as the number of treated vessels, treated lesions, and the stent per patient ratio. At longest available FU, no difference between the 2 study groups was found in terms of cardiac death (18.2% vs 16.3%, P = 0.83), myocardial infarction (2.5% vs 8.6%, P = 0.09), cerebrovascular accidents (0% vs 1.1%, P = 0.98), and target vessel revascularization (TVR) (9.1% vs 16.3%, P = 0.17). Major adverse cardiac and cerebrovascular events‐free survival at 1,500 days in the BMS and DES groups was 57.6% and 50.9% (P = 0.11), respectively.

Conclusions

PCI in patients on chronic HD treatment is associated with a high incidence of adverse events at FU, mainly represented by death. In our study, the use of DES was not associated with a reduction of target lesion revascularization (TLR) and TVR.

     

Patterns of Atrioventricular Conduction During Postexercise Recovery in Patients with Atrial Fibrillation and Wolff-Parkinson-White Syndrome

The effects of the postexercise recovery phase on the functional anterograde conduction properties of the accessory pathway (AP) were evaluated. Twenty-nine patients with Wolff-Parkinson-White (WPW) syndrome were submitted to supine maximal bicycle exercise testing. In seven patients (group I), in whom sustained atrial fibrillation (AF) could be induced by transesophageal pacing (TP), mean ventricular rate (MVR), the shortest R-R interval (SRR) between preexcited beats, and the observed percentage of preexcited beats were evaluated at rest, after each step of exercise and 2 minutes after the end of exercise. In 22 patients (group II), in whom sustained AF could not be induced, decremental TP was performed to evaluate the shortest atrial cycle length (SCL) with 1:1 conduction over AP at rest, after each step of exercise, and 2 minutes after the end of exercise. In four patients in group I, the protocol was repealed with atropine injected during the last minute of exercise. In 12 patients (three from group I and nine from group II), catecholamine plasma levels were measured at rest, at peak exercise, and during recovery. MVR was 144 ± 20 beats/min at rest, 186 ± 21 beats/min at peak exercise (P < 0.001 vs rest), and 179 ± 21 beats/min during recovery (P < 0,001 vs rest; P < 0.05 vs peak exercise). SRR was 289 ± 73 msec at rest, 223 ± 25 msec at peak exercise (P < 0.05 vs rest), and 227 ± 29 msec during recovery. Preexcited beat percentage was 95.4 ± 12 at rest, 35.2 ± 24.2 at peak exercise (P < 0.001 vs rest), and 85.1 ± 22.5 during recovery fP < 0.01 vs peak exercise and n.s. vs rest). In patients in whom atropine was injected MVR was 139 ± 17 beafs/min at rest, 184 ± 19 beats/min at peak exercise (P < 0.05 vs rest), and 172 ± 16 beats/min during recovery (P < 0.05 vs peak exercise, P < 0.05 vs rest); SRR was 320 ± 71 msec at rest, 225 ± 25 msec at peak exercise, and 232 ± 3 inset; during recovery; preexcited beat percentage was 99 ± 1 at rest, 26 ± 18 at peak exercise (P < 0.01 vs rest), and 28 ± 20 during recovery (NS vs peak exercise, P < 0.01 vsrest). In group II. mean sinus rate was 84 ± 12 beats/min at rest, 151 ± 15 beats/min at peak exercise, and 117 ± 21 beats/min 2 minutes after the end of exercise; mean SCL was 328 ± 75 msec at rest, 273 ± 76 msec at peak exercise (P < 0.0001 vs rest), and 280 ± 79 msec during recovery (P < 0.0001 vs rest and NS vs peak exercise). Mean epinephrineand norepinephrine plasma levels (12 patients from groups I and II) were; 4 7.9 ± 76.6 and 355.5 ± 185.1 pg/mL at rest; 193.0 ± 88.0 and 823.9 ± 390.3 pg/mL at peak exercise (P < 0.0001 vsrest); 148.5 ± 94.5 and 672.7 ± 272.3 during recovery (P < 0.001 vs rest; P < 0.01 vs peak exercise). Thus, during early recovery versus peak exercise: SCL and SRR are still lower and confirm the persistence of increased AP conductivity; in patients with atrial fibrillation preexcited beat percentage is markedly enhanced while the duration of preexcited complexes is increased and MVR is still high. The poslexercise recovery phase in patients with WPWand atrial fibrillation determines a higher ventricular response rate with major preexcitation than does rest and peak exercise. The fact that atropine prevents increases in preexcited beats percentage demonstrates that the underlying electrophysiological basis is a discordance of autonomic effects on the conduction properties of the two afrioventricular pathways.     

N-Cyclohexyl-N′ -isopropylcarbodiimide: a hybrid that combines the structural features of DCC and DIC

N-Cyclohexyl-N′ -isopropylcarbodiimide was prepared and used for peptide couplings by various procedures. Reaction between Z-Val and Gly-OEt was used for yield studies and determination of the extent of the side reaction in solution. The value of this reagent for solid peptide synthesis was demonstrated by the synthesis of sequences comprising the 65–74 residues of acyl carrier protein. The efficiency of activation was determined by competition experiments. From all these studies the conclusion can be drawn that N-cyclohexyl-N′-isopropylcarbodiimide is comparable to or even better than the commonly used DCC for mediation of peptide bond formation in solid phase synthesis. By virtue of the solubility of N-cyclohexyl-N′-isopropylurea in dichloromethane, the carbodiimide seems to be a good candidate for practical execution of peptide bond formation by the standard carbodiimide procedure.     

Embolic Accident Following Heparin Therapy for a Left Ventricular Clot Diagnosed by TEE:

There are few data available on the incidence of embolic events inpatients with systemic anticoagulation. We describe a 40-year-old woman in congestive heart failure who was shown by transesophageal echocardiography to have an apical thrombus in the left ventricle without concomitant aneurysm. The patient was started on heparin immediately after the diagnosis was established. Twelve hours later she developed an embolic cerebrovascular accident. We believe that heparin dislodged the thrombus as occurs occasionally with thrombolytic agents used in the treatment of acute myocardial infarction.
transesophageal echocardiography, paradoxical embolization with heparin treatment, left ventricular thrombus     

Is breast feeding the solution to the infant nutrition problem in underdeveloped countries?

One hundred and thirty-three children from birth to 1 year of age were studied to investigate the value of breast milk as a solution to the infant nutrition problem. Fifteen per cent of the children were being fed exclusively breast milk, 44 (44.4%) were fed breast milk plus cow's milk and 40.6% were fed only cow's milk. Thirty-three per cent of the breast fed children, 44.4% of those on mixed feeding and 47% of those on cow's milk alone, were malnourished.     

The Ideal Thrombolytic Agent: GISSI-2 and ISIS-3

Streptokinase (SK) and tissue plasminogen activator (alteplase [tPA]) are by far the most intensively studied thrombolytic agents, but only recently a direct head-to-head comparison (GISSI-2 Trial, in which 12,490 patients have been randomized) has become available to the scientific community. This trial, with its international extension (the International tPA/SK Mortality Trial) recruited more than 20,000 patients, showed that the two drugs tested (SK and tPA) were substantially comparable as far as the clinical events were considered. ISIS-3, the largest randomized clinical trial ever performed, compares SK, tPA, and APSAC in a factorial design. Its results will be available before spring, 1991. It is likely that these two studies, if the results will be consistent, will give a definitive answer about comparison among thrombolytic drugs. As a consequence of that achievement, the interest of the scientific community will possibly be directed towards the long-term prevention of the infarct complications, namely ventricular remodeling and infarct expansion or life-threatening arrhythmias.