Supported angioplasty with synchronized retroperfusion in high-risk patients with left main trunk or near left main trunk obstruction

Trans-Coronary-Venous Interventions

The coronary venous system is routinely targeted during electrophysiological measurements or cardiac resynchronization therapy. However, several novel interventional techniques require coronary venous catheterization and visualization as well as transvenous delivery of devices and/or therapeutic agents. Recent reports suggest the possibility of a transvenous approach for the interventional treatment of refractory angina and mitral valve regurgitation. In addition, the coronary venous system has been used as a route for the delivery of stem cells in patients with left ventricular dysfunction due to ischemic heart disease. We review the potential value of using a coronary venous approach in association with recent therapeutic developments in the interventional treatment of structural and ischemic heart disease. We will also discuss techniques related to coronary venous catheterization.

Coronary pressure measurement to determine treatment strategy for equivocal left main coronary artery lesions

It is often hard to select a treatment strategy for equivocal left main coronary artery (LMCA) disease. We investigated the usefulness of coronary pressure (CP) measurement for determining the treatment strategy in intermediate LMCA disease. We measured CP in 15 consecutive patients with equivocal LMCA disease (age 67.6 +/- 7.5 years, 14 males). Myocardial fractional flow reserve (FFRmyo) was obtained as the ratio of CP distal to the lesion/aortic pressure under maximal coronary dilation. Patients with FFRmyo > or = 0.75 and <0.75 received medical therapy and coronary artery bypass grafting (CABG), respectively, and were followed up for 32.5 +/- 9.7 (20-47) months. Eight patients received medical therapy and 7 patients underwent CABG in accordance with the FFRmyo criteria noted above. FFRmyo of the LMCA was 0.91 +/- 0.01 and 0.61 +/- 0.03 in patients who received medical and surgical therapy, respectively. Neither reference vessel diameter, minimal lumen diameter, nor percent diameter stenosis was significantly different between patients who received medical and surgical therapy. During the follow-up period, no patients with medical therapy showed symptoms due to the LMCA lesion. Similarly, 5 of 7 patients with CABG showed improvement of symptoms and the remaining 2 patients were hospitalized with congestive heart failure. No cardiac death was recorded in the patients with medical or surgical therapy. In conclusion, the present results clearly demonstrated that CP is clinically useful for determining the treatment strategy for equivocal LMCA lesions but coronary angiography is not.

Percutaneous treatment of protected and unprotected left main coronary stenoses with new devices: immediate angiographic results and intermediate-term follow-up

OBJECTIVES

We sought to evaluate the immediate angiographic results and intermediate-term follow-up after percutaneous treatment of left main coronary stenoses in the new device era.

BACKGROUND

Historically, balloon angioplasty of left main coronary stenoses has been associated with high procedural morbidity and poor long-term results. It is not clear whether new devices are more effective in this anatomic setting.

METHODS

Between July 1993 and July 1995, we performed initial left main coronary interventions on 46 patients (mean age 67 +/- 12 years, 26% women). Quantitative angiography was available for 42 of 46 interventions, and clinical follow-up was obtained for all patients at 1 month, 6 months and 1 year after initial revascularization.

RESULTS

Most interventions (42 of 46) were performed in patients with "protected" coronary stenoses to the left coronary system owing to the presence of one or more patent left main coronary grafts. Seventy-seven percent of screened patients were deemed unsuitable for repeat coronary artery bypass surgery. Procedures performed included stenting in 73% of patients (alone in 30% and after rotational atherectomy in 43%), rotational atherectomy in 58% (alone in 15% and before stenting in 43%), directional atherectomy in 4% and angioplasty alone in 7%. Initial procedural success was achieved in all interventions, with no deaths, myocardial infarctions (creatine kinase, MB fraction > 50 IU/liter) or emergent bypass surgery. Follow-up data to date (median duration 9 months, range 6 to 19) demonstrate a 98% overall survival rate and a 6-month event-free survival rate of 78% (six target vessel revascularizations [TVRs], four non-TVRs).

CONCLUSIONS

Treatment of protected left main coronary artery stenoses can be accomplished safely and effectively with new device technology. Intermediate-term follow-up demonstrates an acceptably low rate of death, myocardial infarction or repeat revascularization at 6 months and 1 year.

Strategies for the palliation of severe unprotected left main coronary artery disease: use of newer technologies

Angioplasty of unprotected left main coronary artery lesions is associated with high procedural and late mortalities. We describe the successful use of rotational coronary atherectomy with prophylactic supportive measures in the management of a heavily calcified unprotected left main lesion. This report demonstrates that high-risk lesions, previously regarded as unapproachable, may be safety treated with newer technologies.

Emergency use of cardiopulmonary bypass

Emergency cardiopulmonary support has been used in the United States since 1986. Physicians at participating centers for the National Registry of Elective Supported Angioplasty have contributed data on emergent cardiopulmonary support from their institutions. Results were analyzed to assess the benefits of cardiopulmonary support in patients with hemodynamic collapse. Patients with either cardiac arrest or hemodynamic collapse with cardiogenic shock unresponsive to pressor agents were placed emergently on cardiopulmonary support. Subsequent treatment comprised either angioplasty or surgical revascularization. Patients placed on cardiopulmonary support in < 20 minutes experienced a 41% survival rate across the entire registry of the participating centers of the National Cardiopulmonary Bypass Registry. Two centers with considerable experience demonstrated a 69% survival rate. Patients treated with emergency cardiopulmonary support because of hemodynamic collapse showed improved survival over any other hemodynamic support system. Results have improved for survival with increased operator experience, particularly in the early application group.

Differential effects of synchronized coronary sinus retroperfusion on regional myocardial function during brief occlusion of the left anterior descending and circumflex coronary arteries

To test the hypothesis that coronary sinus retroperfusion would preserve regional myocardial function during either left anterior descending or circumflex occlusion, sonomicrometer crystals were implanted in the midmyocardium of five chronically instrumented dogs. Regional fractional shortening was measured during 5 min of coronary occlusion with and without retroperfusion. Percent fractional shortening in the left anterior descending region fell from 18% at baseline to -4%(dyskinesis) after 3 min of left anterior descending occlusion. With coronary sinus retroperfusion, the percent fractional shortening declined from 16% at baseline to 0 (akinesis) during occlusion. A modest but significant improvement in percent fractional shortening in the ischemic region during left anterior descending occlusion occurred with retroperfusion (p < .05). By contrast, no amelioration of ischemic dysfunction occurred with retroperfusion during circumflex occlusion. Coaxial flow into the great cardiac vein during retroperfusion may provide preferential protection to ischemic myocardium supplied by the left anterior descending coronary artery. However, it is unlikely that the modest degree of improvement in regional function observed during acute left anterior descending occlusion would be mechanically important in the presence of significant ischemic dysfunction.