Bernhard Meier

Risk of side branch occlusion during coronary angioplasty.

To assess the risk of side branch occlusion during percutaneous transluminal coronary angioplasty (PTCA), 600 consecutive procedures were analyzed. On the basis of pre-PTCA angiograms of 557 patients in whom the balloon was actually inflated, 365 side branches in 302 patients (54% of patients) were deemed in jeopardy. A total of 122 side branches in 102 patients (18%) originated from the lesion segment itself, i.e., their take-off was narrowed (Group I, 33% of side branches at risk), whereas 243 side branches in 214 patients (38%) originated from the immediate vicinity of the stenosis in a way that they were subjected to temporary occlusion during balloon dilatation (Group II, 67% of side branches at risk). Patency of side branches was determined by consensus of 2 observers. Criteria for occlusion were disappearance, filling by collaterals, or stagnation of flow. After PTCA, 20 of 365 side branches (5%) were occluded and associated with chest pain in 5 patients, creatine kinase increase in 6, left anterior hemiblock, septal Q waves and transient atrial fibrillation in 1 and non-sustained ventricular tachycardia in 1 of the 20 patients. Exercise tolerance did not decrease. No local predilection for side branch occlusion was evident. Seventeen of 122 side branches (14%) occluded in Group I, compared with 3 of 243 (1%) in Group II (p less than 0.001). Thus, more than half of the patients who underwent PTCA had side branches at risk for iatrogenic occlusion.(ABSTRACT TRUNCATED AT 250 WORDS)

Percutaneous transluminal coronary angioplasty in patients with prior coronary bypass surgery

To improve symptomatic status and avoid reoperation, 122 initial and 7 repeat percutaneous transluminal coronary angioplasty procedures were performed in 116 patients with disabling angina pectoris at a mean of 26.8 months (range 2 to 132) after coronary bypass surgery. Marked angiographic improvement (greater than 30% reduction in diameter stenosis) was obtained in 107 (88%) of the 122 initial procedures and in all 7 repetitions. Mean stenosis was reduced from 78 +/- 13% (mean +/- standard deviation) to 25 +/- 13% (p less than 0.0001) and mean pressure gradient from 49 +/- 15 to 11 +/- 8 mm Hg (p less than 0.0001). Complications were: emergency surgery (three patients), Q wave infarction (one patient), myocardial infarction by enzyme criteria only (four patients) and non-occluding coronary dissection (one patient). There were no neurologic or peripheral vascular complications and no early deaths. One late death occurred 14 months after an unsuccessful but uncomplicated angioplasty procedure. At a mean follow-up of 8.3 months, 88 patients (76%) were free of angina or in improved condition. In patients followed up for at least 6 months, evidence of restenosis occurred in 9 (53%) of 17 saphenous veins, 1 (50%) of 2 proximal graft anastomoses, 4 (18%) of 22 distal graft anastomoses and 5 (14%) of 37 native coronary arteries. When coronary anatomy is suitable, percutaneous transluminal angioplasty is an attractive alternative to reoperation in symptomatic patients with prior coronary bypass surgery.

Higher balloon dilatation pressure in coronary angioplasty

The advent of improved balloon catheters for percutaneous transluminal coronary angioplasty (PTCA) in 1981 extended the theoretic pressure range available for dilatation from 7 atm to 13 atm. The impact of higher dilatation pressure on results of PTCA was studied. The last 100 consecutive patients treated exclusively with the old balloon type (low-pressure group) were compared to the first 100 consecutive patients treated exclusively with the new balloon type (high-pressure group). There was no difference in age, sex, artery distribution, initial degree of stenosis, and initial pressure gradient between the two groups. The mean peak pressure applied was 7.0 +/- 1.6 atm in the low-pressure group and 8.5 +/- 2.1 atm in the high-pressure group (p less than 0.001). The average balloon diameter used and the number and duration of balloon fillings were similar in both groups. Primary success, complications, and residual degree of stenosis were not different in the two groups. The residual pressure gradient, however, was significantly lower in the high-pressure group (11 +/- 7 mm Hg) than in the low-pressure group (16 +/- 10 mm Hg) (p less than 0.01). This indicates a better immediate hemodynamic result without increased risk. It is concluded that it is safe to perform PTCA with the new balloon types allowing for higher pressures. The increment in average pressure used for dilatation, which occurred incidentally, improved the average hemodynamic outcome. This may influence recurrence rate and deserves further investigation by randomized trials.

Learning curve for percutaneous transluminal coronary angioplasty: Skill, technology or patient selection

As with all sophisticated techniques, operators who perform PTCA show a learning curve. It can best be visualized by observing changes in success rate with growing numbers of patients. Thus, the current success rate and complication rate of a particular operator may permit an estimate of the accumulated number of patients treated by that operator. Most likely, the learning curve is also reflected in the rate of long-term success, although it may be obscured by other factors in the variable natural course of CAD. The initial steep upslope of the learning curve is mainly caused by the growing skill of the particular operator. The later, flatter part appears to be secondary to improvements in technical equipment, which take more time. Patient selection has 2 effects on the learning curve that may be self-compensating. If lessons from the past are used for selection and conservatism is preserved, the learning curve will become more pronounced.

Percutaneous transluminal coronary angioplasty. The first five years and the future

Atherosclerosis is a progressive and incurable disease. Its impact on the coronary perfusion is often devastating. killing more people in the civilized world than any other disease. While prevention is moving ahead steadily but slowly. palliation is making headway at a much faster pace. A huge step was taken by Favaloro [I] in 1967 when he implanted the first aortocoronary saphenous vein bypass graft. This method has been refined over the past 14 years to become capable of completely revascularizing the majority of patients with coronary atherosclerosis in the proximal two thirds of the vasculature. Percutaneous transluminal coronary angioplasty (PTCA) [2] was a logical offspring of the balloon angioplasty used in peripheral arteries [3] which was inspired by the telescope-like catheter technique introduced by Dotter [4] in 1964. Since its first application in human medicine on 16 September. 1977 coronary angioplasty has undergone a rapid technical evolution. Today it is considered the method of choice in some patients with coronary artery disease and an equal alternative to coronary artery bypass surgery in others.

Current status of dilatation catheters and guiding systems

Both balloon catheters and guiding catheters for PTCA are high-quality instruments with an advanced degree of reliability and practicality. The standard set-up at Emory University consists of a steerable 3.0-mm balloon catheter and a Judkins-type guiding catheter.

Outcome of Coronary Angioplasty

Most of the overall experience of coronary angioplasty has been collected in patients with single-vessel coronary artery disease. More recently, the indications for coronary angioplasty have been extended to include multiple stenoses and multiple-vessel disease. The recent report from the NHLBI PTCA Registry analyzes the results recorded in 3079 patients enrolled by 105 centers [1]. The mixed data from the Registry include early and limited experience recorded in many contributing centers and may therefore reflect what a patient can realistically expect from coronary angioplasty.

Assessment of Results of Coronary Angioplasty

Assessment of the results of coronary angioplasty is a staged process. The laboratory assessment is followed by the inpatient assessment and finally by the long-term assessment. The laboratory and inpatient assessments combine to give the “primary result” of coronary angioplasty. Long-term assessment of patients after successful coronary angioplasty yields the “long-term result.”