PubMed Health⌕ Search

Biomedical subjects

N Reifart

Publications and source records attributed to N Reifart.

At least 19 recordsLinked to original sources
PubMed1995

Multicenter evaluation of the Strecker tantalum stent for acute coronary occlusion after angioplasty.

The Strecker stent is a balloon-expandable, flexible endoprosthesis constructed of knitted tantalum wire and has been implanted successfully in peripheral arteries. This study presents the first multicenter experience with implantation of this radiopaque device in the coronary arteries in 64 patients of 6591 consecutive percutaneous transluminal coronary balloon angioplasty (PTCA) procedures complicated by abrupt closure. In all except 1 patient the stents (n = 72) were correctly placed, and flow could be reestablished immediately. During hospitalization 12 (19%) patients had stent closures; 5 (8%) patients had Q-wave myocardial infarctions; and 13 (20%) patients underwent bypass surgery (4 on an emergency basis). The in-hospital mortality was 9%: 2 patients died after thrombotic stent occlusions; 2 patients had fatal bleeding complications; and 2 patients died after bypass surgery. Major bleeding complications at the puncture site were observed in 8 (12.5%) patients. Angiograms (n = 45) after 17 +/- 5 weeks revealed a stent patency rate of 89%. Thus the Strecker coronary stent proved to be helpful in the management of acute vessel closure during PTCA. However, in this first series a high incidence of early thrombotic occlusions and bleeding complications warrants close anticoagulation monitoring and limits broader indications.

Angioplasty, Balloon, Coronary↗
PubMed1995

[PTCA or alternative techniques? Balloon angioplasty remains dominant].

The use of second generation devices like excimer laser, rotablator, directional atherectomy, and stents is increasing. It is noteworthy that they are used in most cases in combination with "balloon" dilatation. The application of these more expensive techniques requires more experience and skills than mere balloon dilatation. Today, however, only three randomized trials were able to document some advantage of alternative devices in comparison to the traditional lumen enlargement with balloons (BENESTENT, STRESS, ERBAC). The following paper reflects our experience with balloon angioplasty in more than 15,000 patients, as well a critical review of new devices that were used in 19% of our patients in 1993.

Angioplasty, Balloon, Coronary↗
PubMed1994

[The recanalization of chronic coronary artery occlusions: what factors influence success?].

Between January 1986 and June 1990, recanalization with guide-wire and balloon angioplasty (PTCA) was attempted in 509 patients (416 men, 93 women; mean age 57.5 +/- 9 years) with chronic coronary artery occlusions. The data recorded were analysed to determine the factors which influenced the outcome. The intervention was initially successful in 284 patients (55.8%; circumflex branch: 50%; right coronary artery: 52%; venous bypass graft: 50%; anterior interventricular branch: 64%). The success rate was markedly reduced if (1) the occlusion had persisted for more than 6 months (9.5%; P < 0.001); (2) occlusion had occurred at or after a vessel kink (28.5%; P < 0.001); (3) there had been no vessel "stump" (36%; P < 0.01) and (4) the occlusion was longer than 10 mm (40.7%; P < 0.05). The success-rate was higher if (1) intracoronary anastomoses were absent (61.2%); (2) occlusion had occurred in a straight vessel (62.6%); (3) there had been a vessel stump (64%); (4) the occlusion had persisted for less than 4 weeks (68.5%) and (5) the length of occlusion was < or = 10 mm (75.8%).-These data indicate that the success of PTCA after chronic coronary artery occlusion depended on the site of occlusion, its duration and length, absence of orthograde collaterals and the presence of a vessel stump. Knowing the extent of these factors helps in delineating the indications.

Aged↗
PubMed1994

Current status of the Strecker stent.

Knitted flexible tantalum stents proved to be a valuable adjunct to percutaneous transluminal angiplasty (PTA) in the case of insufficient PTA results, and their use was established in the distal aorta, the iliac, the femoro-popliteal, the renal, and the coronary arteries. Recently, long arterial occlusions were defined as new indications for primary stenting; stent indications were further extended to the subclavian, the carotid, and the splanchnic arteries. Due to higher incidence of acute and late complications after stent treatment of small diameter arteries, patients have to be selected thoroughly. Newly designed drug-releasing stents tested in animal experiments promised to be suitable to diminish the incidence of late restenosis due to intinal hyperplasia, thus providing better long-term patency.

Angioplasty, Balloon↗
PubMed1992

24-hour anti-ischaemic action with once daily nifedipine. Experience obtained with a fatty-alcohol matrix tablet in patients with coronary artery disease.

The ability of a fatty-alcohol matrix, slow-release tablet of nifedipine 60 mg to maintain a 24-hour anti-ischaemic action in the fixed dose of 60 mg once daily has been investigated in a randomised, placebo-controlled, double-blind trial. 12 normotensive patients with angiographically proven coronary artery disease (stenosis of at least one major vessel > or = 70%) were studied. The anti-ischaemic response was assessed over a period of 4 days as changes in the exercise-induced ST-segment depression 6 h and 24 h post-dose, and ST-segment changes in 24-h ambulatory ECGs. A measurable anti-ischaemic response was observed in 8 of the 12 patients. Exercise-induced ST-segment depression 6 h after the administration of nifedipine was reduced by 30% compared to placebo, and there was still a measurable anti-ischaemic response 24-h post-dosing. Both responses were independent of changes in exercise blood pressure. In 7 patients with ischaemic episodes in the 24-h ECGs, nifedipine treatment had only a minor effect on the intensity and duration of ischaemia. It is concluded that a significant anti-ischaemic effect lasting 24 h could be demonstrated using effort-induced ST-segment changes in patients with angiographically proven coronary heart disease, who were treated once daily with nifedipine 60 mg as a fatty-alcohol slow release tablet.

Aged↗
PubMed1991

[Long-term results of coronary angioplasty in relation to vessel size].

Repeat angiography was performed after 3-4 months in 927 of 1386 consecutive patients (67%) who had a successful percutaneous coronary angioplasty (PTCA) between 1986 and 1988. The degree of coronary artery stenosis was determined angiographically before PTCA, immediately after and 3-4 months later. Patients were assigned to one of four groups according to balloon diameter at dilatation: Group 1: 1.5-2.0 mm; group 2: 2,5 mm; group 3: 3.0 mm; group 4: 3.4-4.2 mm. Vessel wall proliferation occurred in all four groups after PTCA. In patients with angiographically demonstrated recurrence (first recurrence: 308 patients, second recurrence: 43 patients) another balloon dilatation was undertaken and a repeat angiography 3-4 months later. Long-term success rate (less than 50% stenosis) differed significantly according to the post-PTCA vessel diameter: 48% in group 1, 63% in group 2, 66% in group 3 and 80% in group 4 (analysis of variance: P less than 0.001). PTCA thus produces better long-term results in large than in small vessels.

Adult↗
PubMed1991

Clinical and Doppler echocardiographic follow-up after percutaneous balloon valvuloplasty for aortic valve stenosis.

Percutaneous balloon valvuloplasty has been shown to increase the aortic orifice area and to improve clinical symptoms. However, there are only few data concerning long-term results after balloon valvuloplasty. In this study, 36 patients (11 men, 25 women, mean age 75 +/- 8 years) were followed after balloon valvuloplasty for a period of up to 18 months by means of clinical parameters and repeated Doppler echocardiographic measurements after 1, 3, 6, 12 and 18 months. Invasive measurements revealed a decrease of the systolic peak gradient from 78 +/- 24 to 38 +/- 13 mm Hg (p less than 0.001), and an increase in the aortic orifice area from 0.58 +/- 0.23 to 0.93 +/- 0.2 cm2 (p less than 0.001). The Doppler echocardiographic approach revealed that the maximal instantaneous gradient decreased from 96 +/- 26 to 67 +/- 22 mm Hg (p less than 0.001). The aortic orifice area increased from 0.49 +/- 0.16 to 0.73 +/- 0.21 cm2 (p less than 0.001). Three patients (8%) died in the hospital. After hospital discharge, 16 patients (44%) died and 8 patients (22%) underwent successful aortic valve replacement after a mean follow-up of 8 +/- 6 months. Nine patients (25%) were alive after a follow-up period of 18 months. Seven of these (19%) remained clinically improved. During follow-up, the Doppler echocardiographic results revealed a continuous trend toward the preprocedural severity of the aortic valve stenosis. Progression of restenosis assessed by Doppler echocardiographic measurements was accelerated in the group of patients who subsequently died or underwent repeat balloon valvuloplasty or aortic valve replacement.

Aged↗
PubMed1991

[The results after prosthetic aortic valve replacement. What effect does old age have?].

Data were retrospectively analysed of 149 consecutive patients with aortic valve stenosis (91 males and 58 females; mean age 64 [27-86] years) who had a prosthetic valve implanted between 1986 and 1988. The overall operative mortality rate was 3.4%, the one-year mortality rate was 4.7%. Operative mortality rate for those aged 27-74 years was 1.7% (2 of 120), but 10.3% (3 of 29) for those aged 75 to 86 years (P less than 0.05). None of the patients in clinical grade III (NYHA classification) died within 30 days of the operation. Among those in grade IV the operative mortality rate was 15.8% (3 of 19) for those aged 75-86, but 4.0% (2 of 50) for those aged below 75 years (P less than 0.05). Valve replacement in symptomatic aortic stenosis with a prosthetic valve is today the method of choice. Operative mortality rate is low, even for patients of advanced age, particularly if the operation is done early.

Adult↗
PubMed1991

[Interventional cardiology--can medical and economic requirements be united?].

Interventional cardiology in a private practice might be problematic for the following reasons: 1) High-risk patients might be rejected in order to avoid complications. 2) The indication for PTCA might be extended to "cosmetic cases". 3) Over cautious dilatation (residual stenosis greater than 50%) might save time and expensive balloon-material. 4) A 24-hour service is unprofitable and might therefore not be offered. This, however, is not acceptable according to medical, ethical, or entrepreneurial reasons, and it is not the philosophy of the two private practices which currently perform PTCA in Germany in Hospital settings. From 1986-1990, 6300 PTCA-procedures were performed in our institution: 83% of patients had complicated stenoses (type B/C), 48% had multivessel disease, 36% had unstable angina, 16% EF less than 40%, and 9.8% were older than 70 years. More than 50% came from other hospitals with catheterization facilities. The primary success rate was 92.2% (stenoses) and severe complications were rare: emergency-CABG 0.3%, in hospital mortality 0.3%. The reasons for this extremely low complication rate are: 1) Large experience due to high volume. 2) Continuous quality control. 3) Much of the profit is reinvesed in employees and equipment hardware. Our example illustrates that economical aspects are not necessarily inconsistent with medical aspects. If interventional cardiology will be extended to other private practices, however, it seems crucial to: 1) allow benefit also to non private laboratories (university, general hospital), 2) establish a program of quality control for all institutions.

Angioplasty, Balloon, Coronary↗
PubMed1991

[Acute vascular occlusion caused by percutaneous transluminal coronary angioplasty: early and late results of repeat-PTCA].

UNLABELLED: Acute vascular occlusion after percutaneous transluminal coronary angioplasty (PTCA) often necessitates a prompt aortocoronary bypass-operation (CABG). Alternatively, a re-PTCA can be attempted. In 1500 consecutive patients there was acute symptomatic occlusion due to PTCA 5 min to 16 h after the operation in 47 cases (3.1%). An immediate re-PTCA was attempted in all cases. RESULTS: Reopening was successful in 43 of 47 cases (91%): in 15 patients (30%) within 30 min, in 36 patients (68%) within 60 min and in 42 patients (89%) within 90 min. In eight patients there was early re-occlusion 30 min to 20 h after re-PTCA, necessitating acute CABG in four patients. In 35 patients with re-PTCA the vessel remained open. Re-stenosis occurred within 1 to 10 days in 10 patients, and in additional 12 patients after 2-4 months. In most cases an additional PTCA was successful. COMPLICATIONS: Six patients had an emergency CABG (three with an exchange wire as a stent in the dissected coronary artery). Three patients died (one after CABG); 14 patients experienced myocardial infarction (30%) (in three of these 14 the infarct was large). CONCLUSION: Acute vascular occlusion after PTCA can successfully be treated by re-PTCA in four of five cases. However a rate of re-stenosis of about 60% is to be anticipated. Reperfusion with re-PTCA is fast and in these patients with transmural ischemia there are obviously less complications in comparison to emergency CABG after PTCA. 60% of the patients remain symptom free or markedly improved and without infarction or emergency CABG after 4 months.

Angina Pectoris↗
PubMed1991

Dose-related antiarrhythmic effects of nicainoprol in patients with chronic ventricular arrhythmias--a double-blind, placebo-controlled, cross-over multicentre trial. Nicainoprol Study Group.

One hundred and three patients with a history of ventricular arrhythmia were screened by baseline 24-h Holter monitoring for a minimal mean number of 30 premature ventricular beats (PVB) per hour. One hundred and one patients were subsequently enrolled in a double-blind, cross-over trial, including four 4-day periods with administration of placebo (PL) or nicainoprol (N.) in doses of 200, 400, 600 mg three times daily in randomized order. Antiarrhythmic efficacy could be evaluated in 61 patients who met all requirements of the protocol, including a complete sequence of valid Holter recordings (greater than 18 h each). Total PVBs were significantly reduced by the 400-mg dose (65%) and the 600-mg dose (71%) as compared to baseline. Two hundred mg N. and PL led to a non-significant reduction of PVBs by 41% and 24%, respectively. An individual response, assumed where there was simultaneous reduction of total PVBs greater than 75%, of ventricular pairs greater than 90% and elimination of ventricular runs, was found in 6 (10%), 10 (16%), 21 (34%), and 22 (36%) patients with PL, 200 mg N., 400 mg N. and 600 mg N., respectively. Four hundred and 600 mg N, significantly prolonged the PR interval (0.17 s and 0.18 s; median values) as compared with baseline (0.16 s), while the QRS duration was significantly increased only by the 600-mg dose (from 0.10 to 0.11 s). Heart rate, mean blood pressure, QT and JTc intervals were not significantly influenced by any dose of N.(ABSTRACT TRUNCATED AT 250 WORDS)

Aged↗
PubMed1990

[Long-term success of coronary angioplasty after repeated treatment].

To ascertain the long-term results after second and third angioplasties for coronary stenosis the coronary angiograms from 1504 consecutive patients with coronary heart disease (1211 men, 293 women, mean age 57 [27-82] years) were retrospectively surveyed. A good initial response (at least 20% reduction in stenosis) was achieved in 295 out of 306 second angioplasties (95.5%), and in all 36 third angioplasties. Viewed overall, these results are significantly better (P less than 0.005) than those achieved at the initial angioplasty (1386 out of 1504 patients; 92.2%). The reduction in the severity of the stenosis achieved at the second angioplasty (from 86 to 24%) and at the third angioplasty (from 86 to 26%) was the same as at the first angioplasty (from 88 to 28%). Serious complications after the first angioplasty were infrequent (death in 0.2%, emergency bypass in 0.4%, myocardial infarction in 0.5%), and no complications were noted after second and third angioplasties. A good long-term outcome (at least 20% reduction in stenosis at 3-4 months) was slightly more frequent after the second and third angioplasties (103 out of 170 [60.6%] and 14 out of 17 patients, respectively) than after the first intervention (532 out of 926 patients; 57.5%). In keeping with these results, the degree of stenosis found at follow-up angiography was significantly lower (first intervention 54.8%, second intervention 50.3%, third intervention 36.9%). There were only 57 patients (3.8%) who ultimately required operative treatment. These figures indicate that the probability of a good long-term outcome from coronary angioplasty increases each time the stretching operation is repeated. Only a very small proportion of patients will require bypass surgery.

Adult↗
PubMed1990

[Treatment of coronary heart disease in the aged. When balloon dilatation, when surgery?].

Data from 3029 consecutive patients (2474 men, 555 women, mean age 59 [20-88] years) in whom coronary heart disease had been diagnosed by coronary angiography were studied with the object of identifying those patients in the older age group who are suitable for treatment by balloon angioplasty. There were 884 patients with a mean age of 70 (65-88) years, and 2145 patients with a mean age of 54 (20-64) years. Single vessel disease was less common in older patients (30% vs 44%; P less than 0.001), double vessel disease was equally common in both groups (28% vs 30%) and triple vessel disease was commoner in the elderly group (42% vs 26%; P less than 0.001). For elderly patients with single vessel disease conservative treatment was chosen in 50%, angioplasty in 49% and operative treatment in only 1%. Of elderly patients with involvement of two arteries, 44% were treated conservatively, 40% by angioplasty and 16% surgically. Of elderly patients with triple artery disease, 23% were treated conservatively, 8% by angioplasty and 69% operatively. This pattern was similar to that among younger patients. The success rate and the incidence of complications after percutaneous transluminal coronary angioplasty were similar in both age groups. In elderly patients with disease of only one or two coronary arteries the prospects of success and the risks are comparable to those in younger patients, but patients with triple artery disease often need bypass surgery.

Adult↗
PubMed1990

[Echocardiographic functional parameters of the left ventricle as a prognostic indicator in coronary heart disease].

The value of two-dimensional cross-sectional echocardiography for the estimation of the left ventricular function had been investigated in 241 consecutive patients with suspected coronary artery disease (CAD). The day before left heart catheterization the left ventricular volumes (EDV, ESV) as well as the global left ventricular ejection fraction (EF) were calculated from the RAO-equivalent in the 2D-echo and in addition the classification of the EF was visually performed from different cross-sections. The coronary angiography showed in 208/241 patients hemodynamically effective stenoses (lumen restriction greater than 50%). For 192/208 patients there were diagnostically usable 2D-echograms as well as clinical data over an observation period of 3 years and 7 months. The 2D-echo correspond quite well to the levocardiography for the calculation of the EDV with r = 0.75, with r = 0.85 for the ESV, and with r = 0.80 for the EF. The mere visual evaluation of the EF out of the 2D-echo agreed well in 84% of the cases to the quantitative determination. During the observation period 18/192 patients died; 17/18 of these patients of cardial causes. Out of the patients with normal EF in the 2D-echo only 3.5% died, with slightly reduced EF 10% died. With highly reduced EF mortality was with 40% significantly increased (p less than 0.001). Thus in patients with CAD unfavourable long-time prognosis may be quickly recognized by their markedly reduced left ventricular function in the 2D-echocardiogram, which shows favourable correspondence to invasive data.

Adult↗
PubMed1990

Surgical correction of a severely obstructed pulmonary artery bifurcation in Takayasu's arteritis.

A young male patient (NYHA III) presented with a severe pulmonary artery bifurcation stenosis of unknown origin. He underwent successful radical resection and endarterectomy of abundant endoluminal and perivascular inflammatory tissue. Surgery was performed with extracorporeal circulation (ECC) without transection of the aorta and the pulmonary artery bifurcation was enlarged with a patch. Right ventricular to peripheral pulmonary artery pressure gradient fell from 80 mmHg preoperatively to 25 mmHg 18 months postoperatively. The patient is fully rehabilitated and working (NYHA I). Histological examination confirmed Takayasu's arteritis as the underlying disease and medium-term follow-up angiography showed an almost normal pulmonary artery bifurcation. We conclude that the radical surgical approach is a valuable palliation in this disease.

Adult↗
PubMed1990

Experimental balloon valvuloplasty of fibrotic and calcific mitral valves.

This study evaluated the mechanism of valvular area expansion during single- and double-balloon valvuloplasty in fibrotic and calcific mitral valves. Special interest was focused on the morphological features of the valves treated. Mitral valves that appeared unsuitable for commissurotomy were excised in toto at the time of mitral valve replacement in 15 patients. The excised valves were mounted in a fluid-filled chamber with a window for photographic evaluation. The chamber was perfused continuously to ensure maximal valvular opening. The valve was photographed, and the orifice area was measured before and after balloon expansion. In addition, the specimens were examined macroscopically and radiographically with regard to calcium content and degree and localization of fibrosis. These data were correlated with splitting of commissures and with rupture of leaflets. Nine valves were fibrotic, and six were calcific. Dilatation was performed first with a single-balloon catheter (diameter, 2 cm) and then with a double-balloon catheter (diameter, 2 and 1.5 cm). After dilatation with one balloon, the average mitral valve area increased from 0.79 to 1.09 cm2, and with two balloons, average area increased to 1.59 cm2. The single-balloon technique caused commissural splitting in nine valves, stretching in three, partial leaflet rupture in one, and no change in two. After the double-balloon technique, commissural splitting occurred in 12 valves and three leaflets were ruptured where severe fibrosis and calcification were mainly located within the commissures. As a rule, after dilatation with the single-balloon technique, the remaining stenosis was still severe, and after dilatation with the double-balloon technique, the remaining stenosis was moderate.(ABSTRACT TRUNCATED AT 250 WORDS)

Calcinosis↗
PubMed1990

Retardation of development and progression of coronary atherosclerosis: a new indication for calcium antagonists?

Development of atherosclerotic lesions in animals, preferrably induced by a high-cholesterol diet, can be successfully suppressed by calcium channel blockers such as verapamil, nifedipine, nicardipine and diltiazem. The issue of a beneficial effect of calcium channel blockers on human coronary atherosclerosis is however not yet settled. At present, three prospective randomized clinical trials with calcium channel blockers (Nifedipine, Verapamil, Nicardipine) are being conducted (INTACT, FIPS, Study of the Montreal Heart Institute). Target variable for assessment of progression in these studies is the severity of coronary atherosclerosis evaluated by angiography both at entry into the study and after 2-3 years of treatment. A total of 445 patients after coronary bypass surgery (CABG) were entered in FIPS (Frankfurt Isoptin Progression Study) and randomly allocated to either verapamil 120 mg t.i.d. or placebo. The extent of coronary atherosclerosis is assessed by repeat angiography both 1 year and 3 years after randomization. Three vessel regions are evaluated separately. 1. Native vessels without bypass grafts and segments distal to the peripheral graft anastomosis ("core region") 2. Segments bridged by bypass grafts and 3. Bypass grafts. The 1-year follow-up was completed by 162 patients (Group A = 80 patients; Group B = 82 patients). There was a homogeneous distribution in the two groups for all clinical variables, graft patency rates, and the incidence of clinical events (myocardial infarction, need for cardiac surgery or PTCA, cardiac death). The overall progression rate of atherosclerosis in the first year was expectedly low.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗