Effect on global and regional left ventricular functions by percutaneous transluminal coronary angioplasty in the chronic stage after myocardial infarction

Comparison of the left ventricular electromechanical map before percutaneous coronary stent revascularization and at one-month follow-up in patients with a recent ST elevation infarction

The study aimed to evaluate the safety and potential of percutaneous transluminal electromechanical mapping (NOGA) in patients with regional myocardial wall dysfunction after a recent ST elevation myocardial infarction (STEMI). Regional myocardial wall dysfunction is a major cause of morbidity in survivors of ST elevation myocardial infarction. Fifteen males who recently had suffered a STEMI were studied prospectively with coronary angiography, ventriculography, and NOGA before and 1 month after percutaneous coronary intervention (PCI). The left ventricular angiographic ejection fraction increased from 50% +/- 11% before PCI to 56% +/- 10% at follow-up (P = 0.006). Qualitative analysis of the NOGA color map identified and outlined an area of regional wall dysfunction in all patients. Quantitative analysis of the NOGA maps showed improvements at follow-up after PCI in regional wall parameters of the infarct area (bipolar voltage: 1.7 +/- 1.4 mV before intervention, 2.2 +/- 1.6 mV at follow-up, P = 0.05; local shortening, a NOGA parameter on wall motion: 3.5% +/- 6.2% before, 7.4% +/- 5.8% at follow-up, P = 0.01), whereas there were no changes in the noninfarcted area (bipolar voltage: 2.7 +/- 2.5 mV before intervention, 2.8 +/- 2.6 mV at follow-up, P = 0.99; local shortening: 7.8% +/- 7.8% before, 8.2% +/- 7.8% at follow-up, P = 0.99). There were no complications to the NOGA procedures. In patients treated with PCI for a recent STEMI, NOGA might be considered used in the quantification of myocardial recovery and in the outlining of myocardial areas of incomplete or no recovery.

Effect of recanalization of chronic total occlusions on global and regional left ventricular function in patients with or without previous myocardial infarction

Previous studies have demonstrated improvement of regional wall motion and global left ventricular function after successful recanalization of chronic total occlusion in coronary artery. However, the difference of benefits of recanalization between infarct site and noninfarct site is unknown. This study assessed the changes in left ventricular ejection fraction, regional wall motion after successful angioplasty of chronic total occlusions with or without previous myocardial infarction. This study also evaluated the factors that influenced the outcome of left ventricular function. We retrospectively studied 75 patients with a successfully recanalized chronic total occlusion in native coronary artery. Left ventriculograms were obtained at baseline and after 6 months. Global and regional left ventricular function were determined. The patients were divided into two groups. Group 1 comprised patients without previous myocardial infarction in the territories of total occlusion vessel that was recanalized. Group 2 comprised patients with previous myocardial infarction in the territories of total occlusion vessel that was recanalized. Left ventricular ejection fraction increased from 53.2% +/- 16.3% at baseline to 57.3% +/- 20.1% at 6-month follow-up in the whole group (P = 0.001). In group 1 patients, the evolution of left ventricular (LV) ejection fraction increased from 59.5% +/- 13.7% to 67.3% +/- 14.6% (P < 0.001). In group 2 patients, the evolution of LV ejection fraction increased, but not significantly, from 48.9% +/- 16.2% to 50.5% +/- 16.9% (P = NS). The evolution of LV ejection fraction increased from 47.6% +/- 17.4% to 50.8% +/- 17.5% (P < 0.05) in the subgroup of recanalization in infarct-related vessel that had rich collateral circulation and had long-term patency. The regional wall motion all significantly improved in group 1 patients (P < 0.05). The regional wall motion did not change in group 2 patients (P = NS). The influence of recanalization of chronic coronary occlusions on the improvement of left ventricular global function was different between myocardial infarction and nonmyocardial infarction patients. The left ventricular function did not improve in myocardial infarction patient. Regional wall motion improved in patients without previous myocardial infarction. For reliable improvement of left ventricular function after recanalization of chronic total occlusions, evidence (not only by symptom or treadmill test) of viable myocardium in recanalized vessel is important. It is also important to keep patency of infarct-related vessel that has good collateral circulation for improving the left ventricular function.

N-terminal proatrial natriuretic peptide in angina pectoris: impact of revascularization by angioplasty

AIMS

We investigated whether levels of N-terminal proatrial natriuretic peptide (N-terminal proANP) reflect the severity of coronary artery disease in chronic, stable angina pectoris. Furthermore, we investigated if revascularization by percutaneous transluminal coronary angioplasty (PTCA) affected the N-terminal proANP level and, finally, whether restenosis could be predicted by changes in N-terminal proANP after PTCA.

METHODS AND RESULTS

N-terminal proANP was measured in 286 patients before and after PTCA. The patients' baseline level of N-terminal proANP (787+/-403 pmol/l) correlated significantly with left ventricular end diastolic pressure, age and serum creatinine, but not with the number of stenotic vessels. Twenty-four hours post-PTCA N-terminal proANP decreased significantly, and completely revascularized patients demonstrated a decline two-fold larger than those incompletely revascularized (deltaN-terminal proANP -114+/-178 vs. -53+/-231 pmol/l, P<0.05). After 14 days N-terminal proANP had returned to baseline in both groups. Changes in N-terminal proANP from post-PTCA to the final follow-up was not predictive of angiographic restenosis.

INTERPRETATION

The significant decrease in N-terminal proANP observed after angioplasty, most pronounced in patients completely revascularized, is thought to reflect a transient improvement in resting left ventricular function.

Effect of percutaneous transluminal coronary angioplasty on exercise in patients with and without previous myocardial infarction

Improvement in exercise capacity is an important clinical effect of percutaneous transluminal coronary angioplasty (PTCA), and was assessed in patients with and without previous myocardial infarction (MI) undergoing PTCA. We prospectively followed patients with exercise testing before and 2 weeks after angioplasty in 415 patients, 170 (41%) of whom had a previous MI. A third exercise test was performed 20 +/- 2 weeks after PTCA in 403 patients. From left ventricular angiography obtained before PTCA, regional dyskinesia was classified into anterior or posterior locations. Both patients with and without previous MI had a significant increase in exercise capacity from before to 2 and 20 weeks after PTCA (previous MI: 31.9% and 29.3%; no MI: 50.7% and 38.2%; p <0.0001 [analysis of variance]). In patients with MI and anterior dyskinesia, in whom lesions on the left anterior descending artery were dilated or posterior dyskinesia in whom lesions on the right coronary artery were dilated, exercise capacity increased significantly from before to 2 and 20 weeks after PTCA (left anterior descending artery: 53.1% and 39.7%, p <0.0001; right coronary artery: 16.9% and 27.6%, p = 0.01 [analysis of variance]). Multivariate regression analysis revealed that male sex, no previous MI, and dilation of left anterior descending artery were significantly associated with increased exercise capacity after angioplasty adjusted for age and smoking habits, whereas left ventricular ejection fraction and end-diastolic pressure were not associated with increased exercise capacity.

Randomised trial of elective stenting after successful percutaneous transluminal coronary angioplasty of occluded coronary arteries

BACKGROUND

The value of angioplasty in occluded coronary arteries is limited by a restenosis/reocclusion rate of 50-70%. In patients with subtotal occlusion, stent implantation has been shown to reduce clinical and angiographic restenosis. Retrospective observational studies have suggested that stenting could reduce restenosis in total occlusions. The value of sustained coronary patency on global and regional left ventricular function in this clinical setting has not been defined clearly.

OBJECTIVES

To assess the medium term effect of elective intracoronary stent deployment after successful percutaneous transluminal coronary angioplasty (PTCA) of an occluded coronary artery.

METHODS

Sixty patients with a total coronary occlusion successfully treated by PTCA were randomised to receive an intracoronary stent or no stent. Patients underwent clinical and angiographic follow up at six months.

RESULTS

Thirty patients received a stent (group A) and 30 were treated by angioplasty alone (group B), all with initial success. One patient in group B required repeat angioplasty with stenting at 24 hours and one patient died after 10 days. Angiographic follow up was available for 57 patients. This showed a significantly reduced reocclusion rate in group A compared with group B (7% v 29%, p < 0.01) and a tendency to a reduced restenosis rate (22% v 40%, p = 0.105) in patients with no reocclusion. Left ventricular function, both global and regional, improved in group A. Only the regional left ventricular function in the area supplied by the target coronary artery improved in group B. Recurrence of symptoms and clinical events such as repeat angioplasty, coronary artery bypass grafting, death or myocardial infarction tended to be reduced in group A (4 (13%) v 9 (30%)).

CONCLUSIONS

Intracoronary stent insertion is effective in reducing the rate of reocclusion and shows a trend towards reduced restenosis after opening of a total coronary occlusion by balloon angioplasty. Sustained patency of the target coronary artery is associated with improvement in global and regional left ventricular function.

Effect of late percutaneous angioplastic recanalization of total coronary artery occlusion on left ventricular remodeling, ejection fraction, and regional wall motion

The clinical benefit of late recanalization of complete coronary occlusion is debated. Left ventricular (LV) function and volumes are major prognostic determinants in patients with coronary artery disease. We sought to assess comprehensively the evolution of global and regional LV function and LV volumes after percutaneous recanalization of chronic complete coronary artery occlusions. A consecutive series of 55 patients who underwent successful percutaneous recanalization of a chronic (> or = 10 days), total (Thrombolysis in Myocardial Infarction trial flow grade 0) occlusion of the left anterior descending or dominant right coronary arteries, and in whom a complete angiographic evaluation was available before angioplasty and at follow-up was studied. At follow-up, 38 patients had a patent artery (group 1) and 17 had a reocclusion (group 2). Baseline parameters were similar in the 2 groups. In group 1, LV ejection fraction increased from 55 +/- 14% to 62 +/- 13% (p <0.001), with an increase in fractional shortening in the occluded artery territory (0.43 +/- 0.30 to 0.71 +/- 0.34, p <0.001), while LV end-diastolic volume remained unchanged. In group 2, ejection fraction and regional wall motion were unchanged, while LV end-diastolic volume index increased (86 +/- 22 ml/m2 to 99 +/- 34 ml/m2, p <0.02). The evolution in LV global and regional function was similar in patients with or without previous myocardial infarction; however, prevention of LV remodeling was observed only in patients with previous infarction. Maintained potency after successful recanalization of totally occluded coronary arteries improves global and regional LV function and, in patients with previous myocardial infarction, avoids LV remodeling.

Effect of delayed percutaneous transluminal coronary angioplasty of occluded coronary arteries after acute myocardial infarction

Whether angioplasty of occluded vessels after myocardial infarction may have beneficial effects on left ventricular function remains unknown. Patients with a first myocardial infarction and thrombolytic therapy who had an occluded infarct-related vessel at delayed coronary angiography were referred systematically for an elective coronary angioplasty performed between 3 and 4 weeks after the myocardial infarction. All patients underwent stress-redistribution-reinjection thallium-201 single-photon emission computed tomography for myocardial viability assessment. Prior angioplasty, a quantitative evaluation of global and regional left ventricular function, was performed. The study group consisted of 38 patients (aged 57 +/- 10 years); 18 had anterior wall infarctions and 20 inferior wall infarctions, but before angioplasty 3 had a patent artery and were excluded. Angioplasty was successful in 30 patients. At follow-up 13 patients (43%) had an occluded coronary artery. In contrast with patients with an occluded coronary artery at follow-up, those with a patent coronary artery had no left ventricular enlargement and had an improvement in both left ventricular ejection fraction (from 48 +/- 9% to 52 +/- 9.8%, p = 0.002) and regional wall motion index (delta = +0.95 SD, p <0.01). In patients with a patent vessel at follow-up, there was a positive correlation between the number of myocardial viable segments and improvement of the infarct zone wall motion (r = 0.52; p = 0.035), and the number of necrotic segments at baseline was positively correlated to the 4-month changes in end-diastolic volume indexes (r = 0.6; p = 0.04). Thus, elective revascularization of occluded coronary arteries with viable myocardium after myocardial infarction improves left ventricular function and lessens remodeling if the artery remains patent during follow-up.

Improvement of global and regional left ventricular function by percutaneous transluminal coronary angioplasty after myocardial infarction

OBJECTIVES

This study was designed to evaluate how elective percutaneous transluminal coronary angioplasty of the infarct-related vessel after acute myocardial infarction affects global ejection fraction and regional wall function.

BACKGROUND

The severity of the residual stenosis of the infarct-related artery after thrombolysis is an important predictor of changes in left ventricular function; however, the optimal time to restore complete perfusion in the infarct area has not been determined.

METHODS

We prospectively evaluated patients with a first myocardial infarction, postinfarction ischemia and residual high grade stenosis with reduced flow in the infarct-related artery who underwent successful coronary angioplasty. The group comprised 74 patients (61 men, 13 women with a mean age +/- SD of 55.9 +/- 9.9 years). Global ejection fraction and infarct region function (expressed as area ejection fraction) were angiographically measured before coronary angioplasty (3.9 +/- 2.1 weeks after infarction) and on routine follow-up study 6 +/- 1 months after angioplasty.

RESULTS

Restenosis with reduced flow occurred in 15 patients (20%). The global ejection fraction in patients with complete flow at follow-up increased significantly from 56.8% +/- 12% to 62.3% +/- 12.5% (p < 0.001). Regional wall motion of the infarct area increased from 12.1% to 22.5% (p = 0.001) in patients with anterior wall infarction and from 20.4% to 28.5% (p = 0.002) in those with inferior wall infarction. In patients with restenosis there was no difference at follow-up either in global ejection fraction (from 47.7% +/- 7.7% to 47.1% +/- 12.7%, p = 0.57) or in regional wall motion of the infarct area.

CONCLUSIONS

Global and regional myocardial dysfunction due to postinfarction ischemia lessens significantly after successful coronary angioplasty of the infarct-related coronary artery with long-term sustained normal, complete flow. In contrast, restenosis with reduced flow prevents long-term improvement of left ventricular function.

Restenosis after delayed coronary angioplasty of the culprit vessel in patients with a recent myocardial infarction treated by thrombolysis

BACKGROUND

Clinical follow-up after percutaneous transluminal coronary angioplasty (PTCA) of an infarct-related lesion has demonstrated a low incidence of recurrent symptoms and repeated revascularization. In the absence of systematic angiographic follow-up, this low rate of clinical restenosis may reflect either a truly lower incidence of anatomic restenosis or the lack of recurrent symptoms in patients with extensive infarction in the territory of the restenotic vessel.

METHODS AND RESULTS

We studied 300 consecutive patients who, after a thrombolysis for myocardial infarction, underwent delayed (10.5 +/- 6 days after the myocardial infarction) PTCA of the infarct-related lesion. Procedural success was obtained in 253 patients (84%), and angiographic follow-up was performed in 205 of this group (81%) at a mean of 7.3 +/- 1.9 months. Restenosis (defined as the recurrence of > 50% stenosis) was present in 105 patients (51%). Only 34 of the 105 patients (32%) with angiographic restenosis were symptomatic; the other 68% had clinically silent restenosis. Of these 105 patients, 27 (13% of the total population undergoing follow-up angiography) had reocclusion at the dilated site at follow-up. The severity of the stenosis at follow-up and the late loss in minimal lumen diameter followed a nearly Gaussian distribution if the lesions that were totally occluded at follow-up were excluded. By multivariate analysis, two independent predictors of reocclusion were identified: a small reference diameter (P < .0005) and the presence of collateral vessels before the procedure (P < .01). Only one factor was associated with restenosis in the 178 patients who did not have reocclusion at follow-up; a Thrombolysis in Myocardial Infarction grade < or = 2 before the procedure (P < .0001). At follow-up, there was a significantly (P < .01) higher ejection fraction in patients without restenosis (56.1 +/- 13.4%) and in patients with restenosis without total occlusion (56.0 +/- 13.8%) than in patients with reocclusion (46.4 +/- 13.0%).

CONCLUSIONS

Despite a satisfactory clinical outcome, delayed PTCA of an infarct-related lesion is associated with a high rate of angiographic recurrence. Two distinct mechanisms account for recurrent stenosis: progressive luminal renarrowing as documented after angioplasty of stable lesions and reocclusion of the infarct-related lesion. Only reocclusion is associated with a deterioration in left ventricular function at follow-up.

Dobutamine echocardiography and resting-redistribution thallium-201 scintigraphy predicts recovery of hibernating myocardium after coronary revascularization

The value of dobutamine echocardiography and resting thallium-201 scintigraphy to predict reversal of regional left ventricular wall motion dysfunction after revascularization in patients with chronic coronary artery disease was assessed. Improvement in wall motion during dobutamine echocardiography and normal or mildly decreased uptake on thallium-201 scanning are strong predictors of reversible left ventricular dysfunction. Dobutamine echocardiography and resting thallium-201 scanning are simple and safe methods of assessing hibernating myocardium.