Coronary angioplasty for medically refractory unstable angina in patients with prior coronary bypass surgery

Percutaneous transluminal coronary angioplasty (PTCA) has been applied with good results to selected patients with unstable angina and to selected patients who have had prior bypass surgery. The population with prior bypass and unstable angina has not been specifically evaluated. This report reviews the results of angioplasty of 45 vessels in 34 patients with medically refractory unstable angina and at least one prior bypass heart surgery. Of these 34 patients, 32 had rest angina; 14 had resting electrocardiographic changes, all 34 were on aspirin 325 mg QD, 31 were on a calcium blocker, 22 were on a beta blocker, 9 were on intravenous nitroglycerin, and 5 required intraaortic balloon counterpulsation for temporary stabilization. Angioplasty of a vein graft was attempted in 17 patients; the left internal mammary was attempted in 4 patients; 24 native coronary arteries in 15 patients were attempted; 3 of the native arteries were protected left main arteries. Of the LIMA angioplasties, 3 were successful; in the 1 unsuccessful case, the occluded anterior descending artery was opened. Of the 17 vein grafts, 16 were successful: 1 had an acute occlusive syndrome and went to surgery with a balloon pump and bail out catheter; his recovery was uneventful. Of the 24 native artery angioplasties, 22 were successful: one patient was technically unsuccessful in the only vessel attempted; he went to semiemergent surgery and recovered uneventfully. In the other, a right coronary lesion was successfully dilated, but an occluded anterior descending artery was not opened. There were no deaths or in-hospital myocardial infarctions.(ABSTRACT TRUNCATED AT 250 WORDS)     

The Short- and Long-Term Outcome of Left Internal Mammary Artery Angioplasty

Failure of internal mammary artery (IMA) bypass grafts is uncommon. However, as their use continues to increase, this complication will be encountered more frequently by interventional cardiologists. The purpose of this article is to describe the short- and long-term outcome of patients undergoing IMA angioplasty through a retrospective review of patients undergoing internal mammary angioplasty at two centers from January 1988 to June 1995. Percutaneous recanalization was attempted on 82 lesions either within an IMA or in the ongoing native left anterior descending artery during 74 procedures in 67 patients. The mean time from bypass surgery was 23 months. The lesion success rate was 84%. Dissection of the IMA occurred in 18% of procedures and was the most common cause for procedural failure and unfavorable outcome. Long-term follow-up was available in 82% of patients at a mean follow-up of 45 months postprocedure. Clinical events occurred in 23 patients (34%) with 4 deaths (1 of which occurred during the initial hospitalization and after emergency bypass surgery), 2 repeat coronary bypass operations, and 17 patients with repeat coronary angioplasties. Despite the high repeat revascularization rate, 80% of patients were asymptomatic or had only infrequent angina at follow-up. We conclude that angioplasty of or through an IMA bypass graft can be performed with a satisfactory procedural success rate and long-term symptomatic benefit.     

Percutaneous transluminal angioplasty in patients with prior myocardial revascularization surgery

Direct myocardial revascularization surgery using either the saphenous vein or internal mammary artery has become the definitive surgical treatment for coronary artery occlusive disease. Certain patients who have undergone these procedures, however, have recurrent myocardial ischemia due to progression of disease in unbypassed vessels, to obstruction in the arteries distal to the insertion of the bypass conduit, or to disease of the conduit itself. Balloon angioplasty may be used to relieve myocardial ischemia in these situations; however, initial studies suggested a low primary success rate coupled with excessive mortality and morbidity. Improvements in patient selection, equipment and technical expertise now allow angioplasty to be performed in this patient population with results comparable to that in the general coronary angioplasty population. Of the 3,016 angioplasty procedures performed between September 1980 and June 1987, 236 patients had previously undergone revascularization surgery. The primary success rate was 93% (390 of 419 stenoses successfully dilated). Overall, clinical restenosis was observed in 39%, including a 43% restenosis rate in patients undergoing only saphenous vein graft angioplasty. This did not differ appreciably from the restenosis rate in postbypass patients undergoing angioplasty of only native vessels (37%) or internal mammary arteries (42%). Emergency revascularization surgery was required in 7 of 236 patients (3%), each of whom had myocardial infarction. One of 236 patients (0.4%) died. Thus, angioplasty may be used to relieve recurrent myocardial ischemia in patients with prior direct myocardial revascularization procedures with a high initial success rate and acceptable risk. Early (less than 6 months) restenosis is not infrequent and remains the largest obstacle to a satisfactory clinical outcome.(ABSTRACT TRUNCATED AT 250 WORDS)     

Percutaneous transluminal angioplasty involving internal mammary artery grafts

With the increasing use of the internal mammary artery as the conduit of choice in coronary bypass surgery, it is anticipated that an expanding patient population will have stenosis, usually at the site of internal mammary-to-coronary artery anastomosis. In our series 31 patients underwent dilatation at either the site of anastomosis (24), the native coronary artery beyond the anastomosis (4), or both (3) with no mortality, myocardial infarction, or need for emergency coronary artery bypass surgery. Angiographic and clinical success was achieved in 28 patients (90%). There were two internal mammary artery dissections with both patients requiring elective coronary bypass surgery. Of the patients in whom dilatation was successful, 22 (79%) have been followed for longer than 6 months and 19 (86%) have had sustained functional improvement at a mean of 35 months after angioplasty. One patient is to undergo repeat coronary bypass surgery. No patient has had a myocardial infarction or died during follow-up. Although percutaneous transluminal coronary angioplasty of the internal mammary artery has inherent difficulties because of the anatomic characteristics of the vessel, it can be performed with a high degree of primary success and a low incidence of complications and can provide long-term clinical improvement.     

Effect of acetylcholine on arterial and venous grafts and coronary arteries in patients with coronary artery disease

Endothelium-dependent vasomotor responses differ in arteries and veins. The transfer of a given vessel from a different vascular bed into the coronary circulation by grafting may affect its endothelial function. In order to evaluate the differences in endothelial function of the internal mammary artery and aortocoronary venous grafts in patients with coronary artery disease, the response to acetylcholine (ach) was examined and compared with that of native coronary arteries. Eighteen patients were examined, including eight with internal mammary artery grafts (9 days to 48 months after surgery), and 10 with saphenous vein grafts (12-96 months after surgery). Ach (70-700 nmol min-1) was infused selectively into a graft on the left anterior descending coronary artery, and the effect on vessel diameters was assessed by quantitative arteriography. In both groups 84% and 83%, respectively, of the arterial segments distal to the bypass anastomosis were contracted by ach (greater than or equal to 70 nmol min-1). The segments of both groups did not show angiographic evidence of local atherosclerosis. A complete occlusion occurred in four cases. In contrast, internal mammary artery grafts were not contracted by ach; in four of 12 segments a dilatation was observed, whereas five of 20 aortocoronary venous graft segments showed a slight reduction in lumen diameter after the highest ach dose applied. The vasoconstricting effect of ach was reversed by intracoronary nitroglycerin. By using ach as an indicator of endothelial dysfunction it is concluded that the internal mammary artery grafts maintained an intact endothelial function after surgery, whereas the coronary artery segments showed an impaired endothelium-dependent vasodilatation. Some of the venous graft segments reacted as coronary arteries did with a less pronounced cholinergic vasoconstriction. This in vivo study supports the observation of a functional superiority of internal mammary artery over saphenous vein coronary grafts.     

Percutaneous transluminal angioplasty involving internal mammary artery bypass grafts: a femoral approach

Percutaneous transluminal coronary angioplasty is an effective technique for the treatment of selected patients with ischemic heart disease due to coronary artery stenosis. Successful angioplasty in saphenous vein bypass grafts has been documented, but little experience has been reported using angioplasty in internal mammary artery to coronary artery bypass grafts. Nine of ten patients with stenosis in the internal mammary artery to coronary artery anastomosis or in the coronary vessel distal to the anastomosis site were successfully treated with angioplasty. One patient developed restenosis 1 month after the procedure, and a repeat angioplasty was successful. In one patient, the balloon catheter could not be advanced through the left internal mammary artery to the stenosis site. Technical features of internal mammary artery angioplasty are discussed, including the use of specially designed guiding wires, guiding catheters, and balloon catheters that facilitate angioplasty involving internal mammary arteries from the femoral approach.     

Coronary flow reserve provided by sequential internal mammary artery grafts

Although internal mammary artery bypass grafts have a high patency rate, the adequacy of blood flow through such conduits, particularly if used sequentially, has been questioned. To evaluate this issue, coronary flow reserve was studied in 20 patients after coronary bypass surgery. Nine patients had sequential internal mammary grafts to the diagonal and left anterior descending coronary arteries; five had a single internal mammary graft to the left anterior descending artery and six had sequential saphenous vein grafts. Fifteen additional single vein grafts were also placed in these patients. Coronary flow reserve was measured after contrast-induced hyperemia by a digital subtraction angiographic technique an average of 25 days after surgery. There was no difference in coronary flow reserve between the proximal and distal anastomotic regions in either the sequential internal mammary graft group (2.14 +/- 0.50 versus 2.29 +/- 0.68, n = 8, p = NS) or the sequential vein group (1.77 +/- 0.49 versus 2.08 +/- 0.78, n = 6, p = NS). In addition, the flow reserve provided to either vascular bed of the sequential internal mammary graft was not different from that provided by a single internal mammary graft (1.64 +/- 0.39, n = 5), a single vein graft (1.95 +/- 0.95, n = 15) or nonstenotic native coronary arteries (2.04 +/- 0.87, n = 34). No cases of intracoronary steal were observed. Although some patients had unequal flow reserves between the proximal and distal anastomotic zones, these occurred in the setting of residual coronary stenoses distal to the site of graft insertion or prior myocardial infarction in the grafted distribution.(ABSTRACT TRUNCATED AT 250 WORDS)     

Hybrid revascularization

OBJECTIVE: To evaluate our initial experience in the combination of two less invasive procedures for myocardial revascularization, coronary artery bypass grafting without cardiopulmonary bypass and immediate posterior angioplasty, on untreated lesions (hybrid revascularization) as an alternative treatment to conventional surgery in selected patients. MATERIAL AND METHODS: From october 1996 to September 1998, 19 patients received hybrid revascularization. The mean age was 64 (47-76). Two patients underwent urgent surgery. Two patients had left main coronary disease, and 9 three-vessel disease. In general, we considered this procedure for patients with high-risk factors for cardiopulmonary bypass and two or more vessel disease. The internal mammary artery was connected to the left anterior descending artery in all 19 patients. All patients were moved to the hemodynamic ward immediately after surgery in 7 cases and before 48 h in the rest, 24 angioplasties were performed. A mean of 2.6 vessels per patient were revascularized and revascularization was complete in 15 patients (79%). RESULTS: One patient had perioperative myocardial infarction. There was no hospital mortality. Length of stay in the intensive care unit was 44 h (IQR = 49) and global postoperative stay was 8 days (IQR = 3.5). In the postoperative angiographic study, before the angioplasty, 95% of mammary arteries (CI 95% 74-100%) and 100% of saphenous grafts (CI 95% 59-100%) were patent. CONCLUSIONS: Combined revascularization allows almost complete revascularization, avoiding complications of cardiopulmonary bypass and minimizing surgical aggression. At the same time, it secures the graft of internal mammary artery to left anterior descending artery.     

Factors affecting early graft patency after coronary grafts

From June 1984 to December 1987, an early postoperative angiographic study was performed in 247 patients who underwent isolated coronary artery bypass surgery. The average age of these patients was 58.6 years, range 31 to 75 years. Preoperatively 50.8% of patients had myocardial infarction and 43.2% of them had unstable angina before surgery. Early coronary artery bypass angiogram was performed in 683 grafts (2.76 grafts per patient): 74 internal mammary artery grafts and 609 saphenous vein grafts. The distribution, location and type of the stenosis, distal coronary artery diameter, segmental myocardial contractility, and distal angiographic coronary filling are analyzed with a matching statistical method. Multivariate analysis showed significant predictors of early graft occlusion to be right coronary and circumflex artery, poor or non visible distal angiographic filling, coronary arteries smaller than 1.5 mm. The univariate analysis associates as risk factors hypokinetic or akinetic territories and multiple stenosis coronary arteries. It can be concluded that the early angiographic study demonstrate that coronary arteries with multiple stenosis, poor distal angiographic filling, smaller than 1.5 mm in diameter, coronary arteries perfusing hypokinetic or akinetic territories and the right coronary and left circumflex artery grafts have significantly lower early cumulative patency rates.     

Robotically enhanced coronary artery bypass surgery

BACKGROUND: Robotically enhanced telemanipulation surgery is a fast developing technique which allows totally endoscopic cardiac surgery with utmost precision and perfection on both beating heart as well as arrested heart. METHODS AND RESULTS: Between December 2002 and February 2004, 125 patients underwent robotically enhanced coronary artery bypass surgery using the da Vinci telemanipulation system (Intuitive Surgical Inc., California). Eleven patients underwent totally endoscopic coronary artery bypass surgery. Of them 9 were done on beating heart while 2 were done on arrested heart. One hundred and fourteen patients had endoscopic takedown of internal mammary artery followed by minimally invasive direct coronary artery bypass in 63 patients and left anterolateral thoracotomy in 51 patients. The internal mammary artery mobilization time was 42 min (35-74 min) while the left internal mammary artery to left anterior descending artery anastomosis time ranged from 20 to 36 min for the totally endoscopic coronary artery bypass patients. In 1 patient, the right internal mammary artery was anastomosed to diagonal artery totally endoscopically. The mean internal mammary artery flow by Doppler measurement done in patients undergoing minimally invasive direct coronary artery bypass was 64 ml/min. Seven patients required conversion to median sternotomy and coronary bypass surgery on beating heart. The mean intensive care unit stay was 1.2 days and the mean hospital stay 4.5 days. There was 1 in-hospital mortality. All 11 patients who underwent totally endoscopic bypass surgery had coronary angiography done at 3 months interval which showed 100% patency in 10 patients while one patient had 50% anastomotic narrowing for which coronary angioplasty was done in the same sitting. CONCLUSIONS: Using telematic technology, a complete endoscopic anastomosis is possible in both single vessel and suitable double vessel disease patients. The use of robotics is now extended to achieve complete myocardial revascularization by harvesting both the internal mammary arteries and making a small thoracotomy for direct anastomosis as well.     

Outcome following emergency coronary artery bypass grafting for failed elective balloon coronary angioplasty in patients with prior coronary bypass

To assess frequency and outcome of emergency coronary artery bypass grafting (CABG) for failed coronary angioplasty in patients with prior CABG, 2,136 elective angioplasty procedures in prior CABG patients were reviewed over a 10-year period. Emergency surgical revascularization was required in 19 patients (0.9%) with prior CABG, compared with 130 of 6,974 patients (1.9%) without prior CABG (p = 0.001). The interval from the most recent CABG to the failed coronary angioplasty was 6.8 years (range 1 to 16). Referral for emergency CABG was made on the basis of an acute closure not responding to repeat dilatation in 12 native coronary arteries and in 7 saphenous vein grafts. Severe hemodynamic instability after acute closure required the placement of an intraaortic balloon pump in 3 patients, including 2 who required cardiopulmonary resuscitation. A total of 34 saphenous vein grafts and 1 internal mammary artery graft were placed emergently. Three patients with high-risk features (3 prior CABG operations in 1 patient, single remaining vessel to heart in 2 patients) could not be weaned from cardiopulmonary bypass. The remaining 16 patients were discharged after a mean hospital stay of 16 days. Four patients developed new Q waves after CABG. At follow-up (mean 52 months, range 3 to 99), 1 patient died late from an acute myocardial infarction. The 15 survivors had no or mild angina and were free of further CABG. Thus, emergency CABG after failed angioplasty in patients with prior CABG is required infrequently. In patients without extreme high-risk features, emergency repeat CABG can be accomplished with good hospital and long-term results.     

Use of 64-slice tomodensitometry after cardiac arrest

Acute coronary occlusion is the leading cause of out-of-hospital cardiac arrest, so patients are usually referred for immediate coronary angiography and angioplasty. We report here the observation of such a patient who previously underwent a coronary artery bypass intervention and who had a difficult arterial access. Moreover, the nature of the grafts was unknown (saphenous and/or mammary arteries). Multi-slice cardiac tomo-densitometry was performed rather than a conventional coronary angiography and it allowed the analysis of native arteries and grafts. There was no stenosis and angioplasty was unnecessary.     

Morbidity following coronary artery revascularisation with the internal mammary artery

To investigate the morbidity after coronary artery bypass grafting, one hundred and seventy-eight patients were retrospectively studied with a minimum follow-up period of one year. Although there was no difference in the incidence and distribution of pain in hospital, seventy percent of patients who had an internal mammary artery used as one of the bypass conduits experienced chest wound pain after discharge from hospital compared to 51.7% of patients who had vein grafts alone (P less than 0.05). Twenty-three percent of patients who had left internal mammary arteries harvested experienced chronic left-sided chest wall pain compared to 4.5% of patients who had vein grafts only (P less than 0.005). The possible factors responsible are discussed and a review made of the complications which may result from using the internal mammary artery in coronary artery surgery.     

An update on internal mammary artery grafting for coronary artery disease

PURPOSE OF REVIEW: To describe recent results regarding the use of the internal mammary artery for coronary artery bypass grafting with emphasis on bilateral internal mammary artery grafting, patency, resistance to atherosclerosis, skeletonisation, composite arterial grafts, flow measurement, vasodilatation, and non-invasive imaging techniques. RECENT FINDINGS: Coronary artery bypass grafting plays an important part in coronary revascularisation and seems to be associated with a survival benefit in comparison with percutaneous coronary intervention. After 10 years, internal mammary arteries demonstrate better patency than vein grafts except when grafting moderately stenosed right coronary arteries. Bilateral internal mammary artery grafting increases survival further, but carries a higher risk of sternal complications. Skeletonisation may reduce this risk. The internal mammary arteries are used increasingly as composite arterial grafts and this technical solution should no longer be considered experimental. Perioperative flow measurement by the transit-time method is recommended while postoperative echocardiography represents an accurate method for evaluation of flow in internal mammary artery grafts. Multi-detector computed tomography allows for accurate assessment of all types of bypass conduits and native coronary arteries. At present, magnetic resonance imaging of internal mammary artery patency and flow is possible. SUMMARY: Newer studies confirm earlier data with respect to improved long-term survival when using internal mammary artery grafting, and this survival benefit is superior to percutaneous coronary intervention treatment. Bilateral internal mammary artery grafting improves survival further. Skeletonisation of the internal mammary artery provides extra length of grafts for complete arterial revascularisation. Non-invasive imaging techniques are increasingly sophisticated and may change the referral pattern for patients with coronary artery disease to either percutaneous coronary intervention or coronary artery bypass grafting.     

Comparison of percutaneous transluminal coronary angioplasty versus coronary artery bypass grafting for multivessel coronary artery disease.

Percutaneous transluminal coronary angioplasty (PTCA) and coronary artery bypass grafting (CABG) are both widely performed in the treatment of multivessel coronary artery disease. Little data directly compare the outcomes of patients treated with these 2 techniques. We examined the characteristics and outcomes of 152 patients who underwent multivessel PTCA and 134 patients who had multivessel CABG. Patients who had prior PTCA or CABG were excluded. Baseline characteristics such as age, sex, and prior myocardial infarction were similar in the 2 groups. Ejection fraction was significantly lower in the CABG group (48 +/- 14%) versus the PTCA patients (53 +/- 15%) (p = 0.002). Narrowing distribution when analyzed by major vascular beds (left anterior descending, circumflex and right coronary arteries) as well as by individual arteries was not significantly different between the groups when left main stenosis was excluded. The surgical group received a larger number of bypasses per patient (3.9) when compared with narrowings dilated in the angioplasty group (3.7) (p less than 0.001). The left internal mammary artery was used in 75% of patients as one of the grafts. Angioplasty success was 95% by standard criteria. Over a mean follow-up of 110 weeks for PTCA patients and 134 weeks for CABG patients the occurrence of death was similar (10 and 14%, respectively) as was myocardial infarction (4 and 2%, respectively). However, all other cardiac events including subsequent cardiac catheterization (49 vs 10%), PTCA (30 vs 2%) and CABG (23 vs 2%) occurred significantly more often in the PTCA group (all p less than 0.001).(ABSTRACT TRUNCATED AT 250 WORDS)     

Sensitivity, specificity, positive predictive value, and negative predictive value of the dipyridamole sestamibi stress test comparing arterial to vein conduits

STUDY OBJECTIVES: To determine the sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) of the dipyridamole stress test (DSST) in predicting > or = 50% obstruction of an internal mammary artery or new native coronary artery disease (CAD) compared with saphenous vein graft obstruction > or = 50% in patients with prior coronary artery surgery and symptoms. DESIGN: In 144 patients with prior coronary artery surgery who underwent a DSST within 8 +/- 7 days of coronary angiography performed because of cardiac symptoms, we investigated the sensitivity, specificity, PPV, and NPV of the DSST in predicting > or = 50% obstruction of an internal mammary artery or new native CAD (201 total arterial conduits) vs > or = 50% obstruction of saphenous vein grafts (total saphenous grafts = 246). SETTING: A university hospital. PATIENTS: The 144 patients included 88 men and 56 women, mean age 68 +/- 9 years (+/- SD). RESULTS: The DSST had a sensitivity of 81%, a specificity of 87%, a PPV of 84%, and a NPV of 84% in predicting > or = 50% obstruction of an internal mammary artery or new native CAD. The DSST had a sensitivity of 88%, a specificity of 82%, a PPV of 86%, and a NPV of 85% in predicting > or = 50% obstruction of saphenous vein grafts. CONCLUSION: There was no significant difference in sensitivity, specificity, PPV, or NPV of the DSST in predicting > or = 50% obstruction of an internal mammary artery or new native CAD vs predicting > or = 50% obstruction of saphenous vein grafts in patients with prior coronary artery surgery and cardiac symptoms.     

Myocardial revascularization using both internal mammary arteries. Clinical results and surgical strategy

To improve the benefits from coronary artery grafting with internal mammary artery (IMA) several technical manoeuvres and methods have been developed to increase the number of coronary arteries and their branches that can be bypassed with internal mammary arteries. Between November 1985 and December 1986, 50 patients underwent a surgical myocardial revascularization procedure using both internal mammary arteries by single or sequential anastomoses and supplemental saphenous vein graft. In 42% of these patients complete revascularization was achieved employing only internal mammary artery grafts. One hundred and twenty-six internal mammary artery grafts (77% of the total coronary bypass performed), were placed. One patient developed perioperative myocardial infarction. Reparative surgery to control immediate post-operative bleeding was required in two patients. Post-operative coronary angiography performed in 30 patients showed all patent internal mammary artery grafts but one. No late deaths occurred. Mean follow-up of 10 months was complete in 50 patients, of whom 94% are symptom free. We conclude that bilateral internal mammary artery grafting can be performed with low operative risk and can provide excellent long-term functional improvement and survival employing only high patency arterial conduit. Moreover, it doesn't significantly increase surgical morbidity.     

Non-invasive coronary bypass graft imaging after multivessel revascularisation

Non-invasive imaging techniques for the detection of graft patency after multivessel coronary revascularisation may be useful for follow-up after surgery. Forty consecutive asymptomatic patients (38 men, age 59.9+/-1.3 years) who had undergone coronary bypass surgery with at least three grafts were examined by spiral computed tomography or magnetic resonance angiography 24.9+/-0.3 months after surgery, using conventional angiography as reference. In total, 133 grafts (37 internal mammary artery, 96 venous grafts) were analysed. Spiral computed tomography studies were performed with a subsecond scanner; for magnetic resonance angiography, a three-dimensional contrast-enhanced gradient echo technique with ultrashort echo time during breath holding was used. For spiral computed tomography, sensitivities were 76% (internal mammary artery) and 100% (venous graft). This was compared with 100% (internal mammary artery) and 92% (venous graft) assessed by magnetic resonance angiography (P=ns). The positive predictive values were 100% for internal mammary artery and venous graft (spiral computed tomography) and 100% (internal mammary artery), 92% for venous grafts studied by magnetic resonance angiography (P=ns). Both subsecond spiral computed tomography and contrast-enhanced magnetic resonance angiography are highly accurate and relatively non-invasive approaches of assessing coronary graft patency after multivessel revascularisation and have potential for follow-up assessment in the long term.     

Early postoperative occlusion of a left internal mammary artery bypass graft with subsequent restoration of patency.

Total occlusion of a left internal mammary artery (LIMA) bypass graft is a rare complication, and reversal of a documented occlusion has not been reported. This is a case of an early postoperative occlusion of a LIMA graft that was found to be patent 4 months later. A patient with three vessel disease (including a moderate lesion in the proximal left anterior descending artery and a severe lesion in its mid-portion) underwent coronary artery bypass grafting with a LIMA to the mid-left anterior descending artery (LAD) and saphenous vein grafts to the right coronary and left circumflex arteries. Coronary angiography 3 months after surgery revealed a totally occluded internal mammary artery and saphenous vein grafts. The patient then underwent a successful angioplasty of the more distal lesion in the LAD. She subsequently returned with recurrent angina. Repeat coronary angiography revealed rapid progression of the disease in the proximal LAD with the more distal angioplasty site being widely patent. Selective arteriography of the internal mammary artery at that time revealed a patent vessel. Thus, the internal mammary graft is a physiologically active conduit that is dependent on flow dynamics. Competitive flow through the nonobstructive native LAD in combination with impedance of flow through the internal mammary artery due to a severe lesion in the LAD distal to the anastomosis led to a functionally occluded LIMA. When the obstruction in the proximal LAD progressed and the distal obstruction was successfully angioplastied, the flow dynamics in the internal mammary improved, allowing for its dilatation and restoration of patency.(ABSTRACT TRUNCATED AT 250 WORDS)     

Percutaneous transluminal coronary angioplasty in patients more than 75 years old: early and long-term results.

Over 4 yr, 102 consecutive patients more than 75 yr old (56 men, 46 women; mean age 78 +/- 3 years, range: 76-89 years) underwent 120 percutaneous transluminal coronary angioplasty procedures. At baseline, 86% had severe anginal symptoms (Canadian class III or IV), 43% had a history of prior myocardial infarction; 61% had multivessel coronary artery disease, and mean left ventricular ejection fraction was 60 +/- 11%. Calcifications were observed on 66% of the dilated arteries. A total of 158 vessels (1.3 vessel per procedure) were attempted: 1 vessel in 89 procedures (74%), 2 vessels in 24 (20%) and 3 vessels in 7 (6%). The primary success rate was 80% per lesion (126/158) and 77% per procedure (92/120). Complications included 3 deaths (3%), 9 Q-wave infarctions (7.5%) and there was no emergency coronary bypass surgery. The primary success rate was significantly related to the absence of coronary calcifications on the dilated segment (88% versus 75%, p < 0.05) and to the initial patency of the dilated artery (subtotal stenosis: 83% versus total occlusion: 53%, p < 0.05). Follow-up data were obtained in the 79 consecutive patients with a duration of follow-up exceeding 8 months. The mean duration of follow-up was 23 +/- 13 months (range 8 to 61 months). No patient was lost to follow-up; 11 patients died (cardiac causes: 7), 2 had a non-fatal infarction, 7 had aortocoronary bypass surgery and 18 had repeat percutaneous transluminal coronary angioplasty.(ABSTRACT TRUNCATED AT 250 WORDS)