Protection of the ischemic myocardium during percutaneous transluminal coronary angioplasty

Therapeutic balloon coronary angioplasty provides a useful model for studying the effects of epicardial coronary artery occlusion in conscious humans. In addition, it is a potent model in which the effectiveness of interventions designed to ameliorate ischemia can be evaluated. Whereas intravenous beta-adrenergic blocking drugs and nitrates appear to have a limited protective effect, the regional (i.e., intracoronary) use of beta-adrenergic blocking drugs and calcium antagonists seem more potent. Currently, coronary venous retroperfusion with arterial blood does not appear practical, and the intraaortic balloon is a useful adjunctive measure in relatively few patients undergoing percutaneous transluminal coronary angioplasty. In contrast, the direct anterograde delivery of oxygen-rich blood or fluorocarbons holds promise as a reliable means of providing local myocardial protection. If ischemia could be markedly reduced, percutaneous transluminal coronary angioplasty might be applied safely in more high-risk clinical settings. In addition, if prolonged balloon inflation could be performed, there might be an increase in primary success rate and possibly a reduction in restenosis rate.     

Intracoronary electrocardiogram during coronary angioplasty.

This prospective study examines the data derived from the intracoronary electrocardiogram (ECG) (derived from the coronary guide wire) compared with that from four standard surface leads (I, II, III, and V2) in documenting myocardial ischemia during coronary angioplasty. Intracoronary and surface ECGs were simultaneously recorded in 300 consecutive patients (mean age 59 +/- 10; range 33 to 80 years; 246 males [82%] during coronary angioplasty in 368 lesions (167 left anterior descending [46%], 85 left circumflex [23%], 107 right coronary arteries [29%], and nine bypass grafts [2%]), before balloon inflation, at 1 minute of inflation, and at the end of the procedure. ST segment changes (greater than 0.1 mV) were observed in the intracoronary ECG in 306 lesions (83%) (151 left anterior descending [88%], 75 left circumflex [89%], and 80 right coronary arteries [73%]) versus in 245 lesions (67%) in the surface ECG (126 left anterior descending [73%], 43 left circumflex [47%], and 76 right coronary arteries [70%]; [p less than 0.0001]). The mean ST segment shift was 0.5 +/- 0.4 mV in intracoronary and 0.1 +/- 0.2 mV in standard leads (p less than 0.0001). ST elevation was seen in 97% of cases with intracoronary ECG changes versus in 83% with surface ECG changes. The remainder had ST depression. A total of 48 lesions (13%) did not produce ECG changes and 62 (16%) had silent ischemia. In 75 lesions (21%), ECG changes were seen only in the intracoronary ECG, compared with 14 lesions (4%) with changes only in the surface ECG (p less than 0.001).(ABSTRACT TRUNCATED AT 250 WORDS)     

Intracoronary urokinase as an adjunct to percutaneous transluminal coronary angioplasty in patients with complex coronary narrowings or angioplasty-induced complications.

The effectiveness of intracoronary urokinase infusion as an adjunct to percutaneous transluminal coronary angioplasty (PTCA) was studied in 50 patients who underwent angioplasty for complex coronary narrowings or had thromboembolic complications during PTCA (29 [58%] men, 3 [6%] stable and 37 [74%] unstable angina, and 16 [32%] prior coronary bypass surgery). The primary indications for intracoronary urokinase infusion were intracoronary thrombus in 27 patients (54%), distal coronary embolization in 9 (18%), and abrupt reclosure in 14 (28%). Urokinase was infused in a mean (+/- standard deviation) dosage of 399,000 +/- 194,000 IU (range 150,000 to 1,000,000) at an average rate of 5,000 to 20,000 IU/min. Angiographic success was achieved in 43 patients (86%). Complications included the need for urgent bypass surgery in 3 patients, Q-wave myocardial infarction in 2, and non-Q-wave myocardial infarction in 12 (8 of whom had peak creatine kinase less than twice the upper normal limit). The incidence of myocardial infarction was significantly higher in patients with vein grafts (69%) than in those with PTCA of native vessels (14%). Two patients died (1 massive gastrointestinal necrosis 24 hours after angioplasty, and 1 after urgent bypass surgery). Mean (+/- standard deviation) fibrinogen levels were 355 +/- 73 mg/dl before urokinase infusion, and 361 +/- 70, twelve hours afterward. Three patients had local bleeding, but no transfusions were needed. It is concluded that intracoronary urokinase is a safe and effective adjunct to PTCA in patients with associated thrombi and may improve the success rate in angioplasty complicated by thrombus formation.     

Acute coronary occlusion during percutaneous transluminal coronary angioplasty.

Two hundred and forty percutaneous transluminal coronary angioplasty procedures were performed in three centres over a two year period. Acute occlusion of the vessel undergoing angioplasty was seen on 20 (8%) occasions. The cause of occlusion was determined angiographically and in some cases confirmed at the time of emergency open heart surgery. The mechanism of coronary occlusion was arterial dissection in six cases, persisting coronary arterial spasm in seven, and coronary thrombosis in four. In three patients the mechanism could not be determined. Immediate reintroduction of a balloon dilatation catheter was attempted in 10 patients and resulted in restoration of adequate coronary flow in six. The remaining 14 patients underwent open heart surgery as an emergency procedure.     

Benign coronary perforation during percutaneous transluminal coronary angioplasty.

In two patients percutaneous transluminal coronary angioplasty was complicated by coronary perforation. In both cases the complication was managed conservatively.     

Myocardial protection by coronary autotransfusion during angioplasty

Coronary autologous blood perfusion may protect the myocardium against ischemia during arterial occlusion due to balloon inflation. During balloon inflation, arterial blood was perfused via the balloon catheter in 19 patients with single proximal severe left anterior descending artery stenosis and normal left ventricular function. Blood was perfused using a contrast medium injector at a flow rate of 40 ml/min. The balloon was maintained inflated for 60 seconds at 6 atmospheres. Two inflations were performed with perfusion and 2 without. Myocardial ischemia was assessed by ST elevations on both the peripheral and intracoronary ECGs, changes in left ventricular systolic and end diastolic pressures and peak positive and negative dP/dt. A positive response was obtained in 11 patients. In 5 patients, the myocardial ischemia induced by dilatation was not alleviated by the perfusion and in 3 patients ischemia was increased by perfusion. In conclusion, ischemia is inconsistently reduced by autologous blood perfusion and its adverse effect in some patients could limit its use.     

Outcome of extensive coronary artery dissection during coronary angioplasty.

A total of 32 (3.6%) patients of 880 undergoing coronary angioplasty during a nine year period at one hospital had extensive dissection (defined as a dissection extending beyond the limits of the dilated angioplasty balloon) in the coronary artery in which the angioplasty procedure was performed. Two (6.25%) of the 32 patients (both of whom were undergoing angioplasty because of unstable angina that was refractory to medical treatment) died as a consequence of the coronary artery dissection. Twelve (38%) needed immediate coronary artery bypass surgery and 11 (34%) had a myocardial infarction, which in four was minor in extent. During follow up, 20 of the 32 patients were successfully managed by medical treatment; only two needed further angioplasty procedures. There were no late deaths. Extensive coronary artery dissection is a serious complication of coronary angioplasty, with a high early mortality and a high incidence of infarction and requirement for bypass surgery. None the less, patients with extensive dissection who are free from the manifestations of acute ischaemia at the end of the procedure can be managed conservatively and have a good immediate and medium term outlook. Attempts should be made to stabilise extensive dissection during coronary angioplasty so that surgical intervention can be delayed or avoided altogether if possible.     

Outcome of extensive coronary artery dissection during coronary angioplasty.

A total of 32 (3.6%) patients of 880 undergoing coronary angioplasty during a nine year period at one hospital had extensive dissection (defined as a dissection extending beyond the limits of the dilated angioplasty balloon) in the coronary artery in which the angioplasty procedure was performed. Two (6.25%) of the 32 patients (both of whom were undergoing angioplasty because of unstable angina that was refractory to medical treatment) died as a consequence of the coronary artery dissection. Twelve (38%) needed immediate coronary artery bypass surgery and 11 (34%) had a myocardial infarction, which in four was minor in extent. During follow up, 20 of the 32 patients were successfully managed by medical treatment; only two needed further angioplasty procedures. There were no late deaths. Extensive coronary artery dissection is a serious complication of coronary angioplasty, with a high early mortality and a high incidence of infarction and requirement for bypass surgery. None the less, patients with extensive dissection who are free from the manifestations of acute ischaemia at the end of the procedure can be managed conservatively and have a good immediate and medium term outlook. Attempts should be made to stabilise extensive dissection during coronary angioplasty so that surgical intervention can be delayed or avoided altogether if possible.     

Significance of balloon imprint during coronary angioplasty.

Balloon imprint during angioplasty is often seen, but not at all inflations. We prospectively studied 235 consecutive patients undergoing 282 PTCAs during a 4-month period, who were divided into two groups: those with balloon imprint during inflation (159 patients, 190 lesions; 67%) and those without (76 patients, 92 lesions; 33%). Clinical and lesion characteristics and immediate outcome were compared. Patients undergoing urgent PTCA had less balloon imprint than those undergoing nonurgent PTCA (14.2% vs. 28.3%; P < 0.005). Although not reaching statistical significance, younger patients and diabetic patients tended toward less balloon imprint (P < 0.06). Patients with observed imprint had less visible thrombus at lesion site (31.1% vs. 42.4%; P < 0.05), and a tendency without statistical significance toward more dissections but less acute closure was observed (P < 0.07). In addition, more stents were implanted in the imprint group (79.5% vs. 66.3%; P < 0.02). Patients needing pressure > 6 atm to break the imprint had more eccentric lesions (68% vs. 27.1%; P < 0.000) and more dissections (13.9% vs. 5.1%; P < 0.03) than those needing lower pressure. Patient and lesion characteristics may determine the appearance of balloon imprint at PTCA, which in turn influences the procedure and its immediate outcome. Cathet Cardiovasc Intervent 2001;53:331-333.     

Hemopericardium caused by coronary perforation during angioplasty. A surgical diagnosis

A case of haemopericardium occurring during angioplasty of the left anterior descending artery complicated by an occlusive dissection is reported. The haemopericardium was diagnosed and evacuated during surgical myocardial revascularisation indicated by the failure of angioplasty. This complication, though rare, underlines the necessity of a real surgical stand-by for this procedure.     

Dobutamine stress echocardiography before and after coronary angioplasty.

Myocardial function was assessed by stress echocardiography in 28 patients before and after successful elective coronary angioplasty. Dobutamine stress echocardiography was performed using up to 40 micrograms/kg/min, followed by the addition of atropine in 20 patients to achieve 85% of the predicted maximal exercise heart rate. The initial studies were performed 1 day before and the second ones within 3 days (mean 1.3) after angioplasty. Peak heart rates and systolic blood pressures were the same for the 2 studies. The frequency of dobutamine-induced new wall motion abnormalities decreased from 20 (71%) before to 4 (14%) after angioplasty (p less than 0.0001). Before angioplasty, wall motion score index (an indicator of left ventricular wall motion, an increase in which indicates impaired wall motion due to myocardial ischemia) increased from 1.06 at rest to 1.23 at peak stress (p less than 10(-6)), but there was no significant increase in this index in the study after angioplasty. Before angioplasty, 14 patients (50%) developed chest pain during the stress test compared with 6 (21%) after angioplasty (p = 0.05), and before angioplasty, the stress test was stopped before the target heart rate was achieved, because of symptoms, ST-segment change or severe new wall motion abnormality in 14 patients compared with 7 after angioplasty (p = 0.09). Thus, early after angioplasty there is a reduction in myocardial ischemia as assessed by dobutamine stress echocardiography.     

Pseudoaneurysm of coronary artery following rupture of coronary artery during coronary angioplasty.

Rupture of the coronary artery is a rare complication of percutaneous transluminal coronary angioplasty (PTCA). We describe a case of coronary artery rupture during PTCA resulting in the formation of a coronary artery pseudoaneurysm. The pseudoaneurysm was successfully treated by percutaneous spring-coil embolization of the coronary artery.     

Balloon rupture during coronary angioplasty

Out of a total of 1,500 percutaneous coronary angioplasties (PTCA), 55 (3.6%) were associated with balloon rupture. Lesion calcification was noticed in 7 of these 55 patients (12.7%). Balloon rupture occurred at a mean pressure of 10.7 atmospheres. All balloons were retrieved without difficulty. Intimal tears were noted in 18 (32.7%) cases. Three patients required bypass surgery. In 29 patients restudied angiographically, the restenosis rate was 38%. Balloon rupture during PTCA does not seem to be associated with detrimental consequences.     

Cardiac rupture during coronary angioplasty

Cardiac rupture is a catastrophic complication of acute myocardialinfarction. We describe a patient with acute myocardial infarctionwho received thrombolytic therapy and then developed cardiacrupture and tamponade during rescue angioplasty.     

Protective effect of collateral vessels during coronary angioplasty.

To assess the potential protective role of collateral vessels 27 patients undergoing angioplasty of the left anterior descending coronary artery were studied by intravenous digital subtraction left ventriculography. Fifteen patients had no collateral vessels (group 1) and 12 had some degree of collateral supply (group 2). During balloon inflation ST segment elevation in group 1 (4.9 mm) was significantly greater than that in group 2 (0.9 mm). Similarly the reduction in left ventricular ejection fraction was significantly greater in group 1 (24%) than in group 2 (12%). Both the size of ST segment elevation and the fall in ejection fraction correlated inversely with the extent of the collateral supply (r = -0.680 and r = -0.446 respectively). During balloon occlusion of the anterior descending coronary artery the percentage shortening of the anterior and apical segments fell in both groups but apical shortening fell to a lesser extent in group 2. An additional reduction in anterobasal contraction was confined to group 1. Electrocardiographic and ventriculographic manifestations of ischaemia produced by balloon inflation during angioplasty are less pronounced when collateral vessels are present. This suggests that the collateral circulation can protect myocardium at risk of ischaemia after coronary occlusion.