Karleif Vatne

Restenosis and clinical outcome in patients treated with amlodipine after angioplasty: results from the Coronary AngioPlasty Amlodipine REStenosis Study (CAPARES).

OBJECTIVES Our intent was to investigate the effect of the dihydropyridine calcium channel blocker amlodipine on restenosis and clinical outcome in patients undergoing percutaneous transluminal coronary angioplasty (PTCA). BACKGROUND Amlodipine has sustained vasodilatory effects and relieves coronary spasm, which may reduce luminal loss and clinical complications after PTCA. METHODS In a prospective, double-blind design, 635 patients were randomized to 10 mg of amlodipine or placebo. Pretreatment with the study drug started two weeks before PTCA and continued until four months after PTCA. The primary angiographic end point was loss in minimal lumen diameter (MLD) from post-PTCA to follow-up, as assessed by quantitative coronary angiography (QCA). Clinical end points were death, myocardial infarction, coronary artery bypass graft surgery and repeat PTCA (major adverse clinical events). RESULTS Angioplasty was performed in 585 patients (92.1%); 91 patients (15.6%) had coronary stents implanted. Follow-up angiography suitable for QCA analysis was done in 236 patients in the amlodipine group and 215 patients in the placebo group (per-protocol group). The mean loss in MLD was 0.30 +/- 0.45 mm in the amlodipine group versus 0.29 +/- 0.49 mm in the placebo group (p = 0.84). The need for repeat PTCA was significantly lower in the amlodipine versus the placebo group (10 [3.1%] vs. 23 patients [7.3%], p = 0.02, relative risk ratio [RR]: 0.45, 95% confidence interval [CI]: 0.22 to 0.91), and the composite incidence of clinical events (30 [9.4%] vs. 46 patients (14.5%), p = 0.049, RR: 0.65, CI: 0.43 to 0.99) within the four months follow-up period (intention-to-treat analysis). CONCLUSIONS Amlodipine therapy starting two weeks before PTCA did not reduce luminal loss, but the incidence of repeat PTCA and the composite major adverse clinical events were significantly reduced during the four-month follow-up period after PTCA with amlodipine as compared with placebo.

Hemodynamic evaluation of the carbomedics prosthetic heart valve in the aortic position : comparison of noninvasive and invasive techniques

Seventy-three patients with a CarboMedics aortic bileaflet valve prosthesis were examined by Doppler ultrasonography, and 27 of them were also assessed by transseptal catheterization. The ultrasonic mean systolic gradient was 17.1 +/- 5.6 mm Hg for valve size 19 mm, falling gradually with increasing valve size to 6.8 +/- 2.5 mm Hg for size 27 mm. The catheter mean systolic gradient was consistently smaller than the ultrasonic gradient (4.3 +/- 4.8 mm Hg), but Tobit regression analysis showed a significant association between the two methods. In all patients both methods revealed negligible to small amounts of retrograde leakage, which is assumed to be a normal finding for this valve. The effective flow areas of the valves calculated from the ultrasonic data were similar to the in vitro calculated flow areas. The hemodynamic potential of this valve is therefore completely utilized in vivo. The effective orifice area corrected for body surface area increased with increasing valve size, which demonstrates a moderate valve-patient mismatch.

Safety of the nonionic contrast medium omnipaque in coronary angiography.

The low osmolar nonionic contrast medium Omnipaque was used in 5,339 consecutive coronary angiographies and serious complications were registered. Myocardial infarction occurred in 4 patients, of whom 2 died, and ventricular fibrillation in 1. Cerebral embolism occurred in 11 patients, all of whom survived. The results are compared with those of previous series of coronary angiography with high osmolar ionic media. It is concluded that use of the nonionic medium Omnipaque resulted in a significant reduction of the frequency of serious complications.

Intraoperative Angiography in Minimally Invasive Direct Coronary Artery Bypass Grafting

Intraoperative angiography in minimally invasive direct coronary artery bypass grafting without cardiopulmonary bypass and in hybrid procedures is reported. Twelve procedures were performed in a specially designed surgical-radiologic suite with a cross-disciplinary organization. In 2 patients the anastomosis was successfully revised on the basis of angiographic findings. In 4 of the 12 patients anastomosis of the left internal mammary artery to the left anterior descending coronary artery performed as a minimally invasive direct coronary artery bypass grafting procedure was combined with percutaneous transluminal coronary angioplasty of lesions in other coronary vessels in the same session. Intraoperative angiography allows a reliable diagnosis of an anastomosis or graft failure and prompt and reliable correction, and it allows the combination of minimally invasive direct coronary artery bypass grafting and angioplasty in one session.

Occurrence and management of fractured peripheral catheters in CSF shunts.

A series of 716 children underwent 2065 cerebrospinal fluid shunt procedures. Shunt failure due to fracture of the peripheral drain occurred 60 times, 38 times in ventriculo-atrial and 22 times in ventriculo-peritoneal shunts. The break occurred most commonly 2–4 cm above the neck incision in cardiac and just cephalad to the clavicle in abdominal drains. Fifty-nine ruptures occurred in Pudenz catheters (which were used in 82% of the shunts) and 1 occurred in a Holter drain (used in 17%). The fractured atrial catheters remained in situ (5/38) or were dislodged into the right cardiac ventricle (14/38), pulmonary arteries (9/38), right atrium (5/38) or hepatic veins (3/38). Two of the ruptured drains could not be located. Removal by a percutaneous transvascular snare technique was attempted in 27 cases and was successful in 24.

Should the Lungs Be Ventilated during Cardiopulmonary Bypass? Clinical, Hemodynamic, and Metabolic Changes in Patients Undergoing Elective Coronary Artery Surgery

No beneficial effects were achieved by ventilating the lungs of a group of 10 patients during total extracorporeal circulation for coronary artery bypass operation. Ventilation of nonperfused lungs, which was suggested to prevent postoperative atelectasis, may even have negative effects. Intrapulmonary shunting increased significantly (p less than 0.05), while the shunt fraction in the nonventilated lungs of another group of 10 patients remained unchanged. There were only minor differences between the two groups with respect to systemic and pulmonary hemodynamic changes.

Reproducibility of Ischaemic Lactate Metabolism during Atrial Pacing in Man

The reproducibility of myocardial ischaemia provoked by atrial pacing was studied in two groups of patients. The heart rate was slowly increased (10 beats per fourth min) until angina in group A, and quickly increased (10 beats per 20 s) in group B. Cardiac venous flow was measured by thermodilution and blood was sampled for metabolic studies at rest and during the maximum obtained heart rate and repeated after 20 min of rest. Ischaemia was defined as a reduction in myocardial lactate extraction ratio by 50% and to a ratio lower than 0.15. Lactate metabolism changed from production (-0.06 +/- 0.05) during the first pacing to extraction (0.05 +/- 0.05) during the second in group A (p less than 0.02). Lactate metabolism was quite reproducible in group B. All the other metabolic and haemodynamic parameters were unchanged in both groups. We conclude that the duration of atrial pacing is important for the reproducibility of pacing-induced myocardial ischaemia.

Pulsatile vs. non-pulsatile flow during cardiopulmonary bypass: a comparison of early postoperative changes

The aim of the study was to evaluate possible haemodynamic and metabolic effects of pulsatile flow in cardiopulmonary bypass. The subjects were 20 patients undergoing coronary artery bypass grafting. They had no complicating diseases. Ten consecutive patients with pulsatile perfusion were compared with ten consecutive patients with non-pulsatile perfusion. The haemodynamic parameters, chest X-rays, fluid balance and changes in circulating thrombocytes were unaffected by adding pulsatile flow to cardiopulmonary bypass. The arterial-venous oxygen content difference and intrapulmonary shunting were also unaffected. Whole-body oxygen consumption was higher in the pulsatile group immediately after bypass, but subsequently there were no differences. The haemoglobin and haematocrit values were higher in the non-pulsatile group two hours postoperatively, but did not differ in the rest of the observation period. The clinical course was similar in the two groups.

Early Postoperative Changes with Different Priming Solutions in Open-Heart Surgery

The consequences of substituting dextran 70 (Macrodex) for human plasma in the priming solution were studied during the first 48 hours after open-heart surgery. Twenty patients undergoing elective surgery for coronary artery disease were selected for the study. Clinical, haemodynamic, metabolic and roentgenologic parameters were monitored. No major differences were found between results with use of plasma or dextran (each in 10 patients). The lower pulmonary capillary wedge pressure in the dextran group may indicate better left ventricular performance. As human plasma is a limited resource and is a potential disease transmitter, dextran 70 may with advantage replace human plasma in the priming solution, and at much lower cost.

FAILURE OF COMBINED ACETYLSALICYLIC ACID AND DIPYRIDAMOLE TO PREVENT OCCLUSION OF AORTOCORONARY VENOUS BYPASS GRAFT

Patients scheduled to receive at least three aortocoronary venous bypass grafts were randomized to active medication or to placebo. The former were given dipyridamole (DP) preoperatively and acetylsalicylic acid (ASA) was added after the operation. For the next 3 months they received DP 75 mg and ASA 325 mg thrice daily. The placebo regimen was identical and the study was conducted with double-blind technique. One patient in each group died. DP-ASA was discontinued in six patients because of gastrointestinal side effects (bleeding peptic ulcer in 2 cases). Angiography after 3 months revealed the patency rate of individual grafts to be 68% in the DP-ASA group and 77% in the placebo group. DP-ASA therefore did not prevent occlusion of aortocoronary venous bypass grafts.