[Traumatologic risk in ambulatory cardiac rehabilitation groups to leisure time sports groups of healthy athletes]. / Risiko von Sportverletzungen in ambulanten Herzsportgruppen im Vergleich zu Freizeitsportgruppen Gesunder. Sportverletzungen in der ambulanten kardiologischen Rehabilitation.

INTRODUCTION: Rehabilitation in ambulatory heart groups has become well established in comprehensive cardiac care. The prevention of injuries is critical to the safety and efficiency of the program. METHODS: Questionnaires were mailed to the ambulatory heart groups in the state of Hessen, Germany and answered by 1935/13 000 (15 %) patients (65.9 +/- 7.6 years, 1504/1935 (77.7 %) men covering approximately 674,000 patient exercise hours. RESULTS: Seventy-eight of the 106 (73.6 %) injuries reported occurred during games encompassing 28/106 (26.4 %) strains, 24/106 (22.6 %) bruises, 17/106 (16.0 %) sprains, 11/106 (10.4 %) bone fractures, 6/106 (5.7 %) ruptured tendons, 8/106 (7.5 %) ruptured muscles, 3/106 (2.8 %) ruptured ligaments, and 9/106 (8.5 %) miscellaneous. The injury risk was neither related to the cardiovascular diagnosis, the prevalence of diabetes, body mass index, previous sport experience, duration of participation in rehabilitation programs, nor to the participant's age. Patients on anticoagulants or after cardiovascular surgery had no excess risk. Gender was the only independent predictor of injuries. In men the overall incidence of injuries was higher (97/1504 [6.4 %]) than in women (9/431 [2.1 %]), p < 0.0005) while the severity was higher in women (6/9 = 66.7 % vs. 22/97 = 22.7 % p < 0.001). The injuries were treated by elastic bandages or band-aids in 69/106 (65.1 %), by splinting in 4/106 (3.8 %), by local injections in 4/106 (3.8 %), by massages in 3/106 (2.8 %), and by others in 26/106 (24.5 %). Five of the 106 (4.7 %) injuries required hospitalization. CONCLUSION: The traumatologic risk in the rehabilitation of cardiovascular outpatients is associated with a low incidence of injuries.

A polyhydroxybutyrate biodegradable stent: preliminary experience in the rabbit.

PURPOSE: The lifelong persistence of foreign bodies within the arteries may contribute to restenosis. Thus, biodegradable devices might decrease recurrence rates. METHODS: Eleven polyhydroxybutyrate biodegradable stents and 13 tantalum stents were implanted into the iliac arteries of New Zealand white rabbits for up to 30 weeks. After killing the animals, the specimens were harvested, fixed in formalin, processed in paraffin, and stained. RESULTS: Polyhydroxybutyrate instigated intense inflammatory and proliferative reactions with an increase in collagen (2.4- to 8-fold vs native segments), thrombosis and in-stent lumen narrowing (375.5-606.6 mm vs 655.6 +/- 268.8 mm in native segments). The elastic membranes were destroyed in all specimens. The tantalum stents increased the in-stent lumen progressively (769.7 +/- 366.6 mm vs 1309.9 +/- 695.3 mm), penetrated the external elastic membrane, and increased mural collagen content (6- to 8.6-fold vs native segments). Neither restenoses nor thromboses occurred. CONCLUSIONS: In the rabbit iliac artery, polyhydroxybutyrate stents caused intensive inflammatory vascular reactions which ban them from clinical use.

Controlled balloon inflation reduces long-term restenosis after percutaneous transluminal coronary angioplasty.

PURPOSE: The trauma induced by balloon angioplasty has an impact on the outcome of coronary interventions, such as stent procedures. However, balloon inflation for PTCA is not yet standardized even though procedural and long-term outcomes might be affected. METHODS: During routine PTCA, a total of 454 patients [mean age, 60.9 +/- 9.0 years; 162 (35.7%) with 1-vessel disease; 159 (35%) with 2-vessel disease; 133 (29.3%) with 3-vessel disease] were allotted to computer-assisted dilatation (CAPS) with a pressure slope of 0.2 bar/s (CAPS 0.2; n = 149 patients), 1.0 bar/s (CAPS 1.0; n = 154 patients) or to standard inflation with a hand-driven pump (n = 151 patients). Angiographic follow-up rates after 4.1 +/- 3.2 months were 88.1% for the hand-driven pump, 94% for CAPS 0.2 and 87.7% for CAPS 1.0. RESULTS: Flow reducing (1.3-2.0%) and non-flow reducing (12.6-14.9%) dissections were equally distributed among all groups as were major adverse cardiac events (2.6-4.0%). The stent rate was 1.3% with the hand-driven pump, 0.7% with CAPS 0.2 and 1.3% with CAPS 1.0. Angiographic restenosis rate was 48.9% with the hand-driven pump, 44.3% with CAPS 0.2 and 32.6% with CAPS 1.0. (hand-driven pump versus CAPS 1.0, p < 0.007; CAPS 0.2 versus CAPS 1.0, p < 0.049). CONCLUSIONS: The pressure slope during balloon inflation in PTCA has a significant impact on restenosis. The impact on stent procedures has yet to be determined.

[First results in an animal model on stents sheathed with a polytetrafluoroethylene membrane]. / Erste tierexperimentelle Ergebnisse eines von einer Polytetrafluoroethylenmembran umhüllten Koronarstents.

OBJECTIVES: Mechanisms of restenosis after coronary stent implantation include marked intimal proliferation as well as vascular tissue protrusion through the meshes. Thus, stent sheathed with membranes may be an alternative to improve the long-term outcome. METHODS: Seventeen cylindric serpentine shaped 316L stainless steel stents (nominal diameter 3.0 mm, length 15 mm) lined and covered by a polytetrafluoroethylene (PTFE) membrane and 10 unsheathed devices were implanted into the iliac arteries of 14 New Zealand White Rabbits for an observation period of 1 - 10, 11 - 20, and 21 - 30 weeks. After sacrificing the animals, specimens were harvested, fixed in formalin, processed in paraffin, serially sliced into 5 microm thick preparations, and stained (hematoxylin & eosin, elastica von Gieson). RESULTS: The polytetrafluoroethylene membrane stents increased the vascular lumen significantly (p < 0.04) to 1185.3 - 1620.4 microm compared with the native segments (655.6 +/- 268.8 microm). In the stainless steel stents the lumen decreased from 1873.1 microm to 719.1 microm. None of the devices penetrated the internal elastic membrane. There was no inflammatory vascular reaction. Compared to the native segments, the amount of elastic fibres was slightly less (native: 8.9 %, PTFE: 2.3 - 3.5 %, without PTFE: 1.9 - 5.5 %) whereas the collagen fibres increased marginally (native: 5.1 %, PTFE: 6 - 6.9 %, without PTFE: 6.4 - 8.4 %). CONCLUSIONS: In the rabbit iliac artery, stents sheathed with a microporous polytetrafluoroethylene membrane showed good tissue compatibility with no restenosis. These results warrant clinical trials.

Erythrocyte deformability in Waldenström's macroglobulinemia.

The deformability of erythrocytes in Waldenström's Macroglobulinemia (WM) patients are analysed by shear stress diffractometer in vitro. Erythrocytes obtained from blood samples of WM patients are subjected to well defined shear forces, varying from 0.3 to 60 Pa, and their corresponding elongation indexes generated by diffraction pattern of a laser beam are recorded. For comparison, equal number of samples from normal adult volunteers is also studied. The results show a shear dependent decrease in deformability index in WM patient samples. The decrease in deformability index of WM patients is significant at high shear forces (>12 Pa) when compared to those of normal samples whereas it is not significant at low shear forces. As the deformability of erythrocytes together with elevated plasma viscosity and enhanced erythrocyte aggregation may cause potential flow stagnation at microvasculature, these studies are clinically relevant.