Optimisation of the management of patients with coronary heart disease and type 2 diabetes mellitus

Type 2 diabetes mellitus is a prevalent disease in Westernised society, and more than 50% of individuals with diabetes mellitus die from cardiovascular causes. The underlying metabolic defect of type 2 diabetes mellitus is a combination of insulin resistance and decreased secretion of insulin by pancreatic beta-cells. Insulin resistance commonly precedes the onset of type 2 diabetes mellitus and is usually associated with a metabolic syndrome including hypertension, dyslipidaemia and obesity. Treatment of known cardiovascular risk factors, including hyperglycaemia, dyslipidaemia, hypertension and smoking, plays a key role in delaying the onset and progression of coronary heart disease (CHD) and other forms of atherosclerosis in patients with diabetes mellitus. Sulphonylureas should be used with caution in patients with CHD but aspirin (acetylsalicylic acid), beta-blockers and ACE inhibitors play an important role in the medical management of patients with established coronary artery disease and diabetes mellitus. Patients with diabetes mellitus represent a higher risk group of patients after both percutaneous and surgical coronary revascularisation and the decision regarding the choice of revascularisation procedure should take into account angiographic characteristics, clinical status and patient preference. Patients presenting with diabetes mellitus and acute myocardial infarction should be considered for reperfusion therapy with either urgent thrombolytic therapy or primary percutaneous coronary intervention.

Primary percutaneous coronary interventions in patients with acute myocardial infarction and prior coronary artery bypass grafting

BACKGROUND

The outcome of patients with previous coronary artery bypass grafting (CABG) undergoing primary percutaneous coronary intervention (PCI) for the treatment of acute myocardial infarction (AMI) is unclear. We sought to assess the outcome of patients with prior CABG undergoing primary PCI for the treatment of AMI.

METHODS AND RESULTS

Between 1991 and 1997, 1072 patients with AMI underwent primary PCI without antecedent thrombolytic therapy at the Mayo Clinic. There were 128 patients with previous CABG and 944 without previous CABG. Patients with previous CABG were further subdivided according to the treated vessel: native vessels (n = 65) and bypass graft (n = 63). Clinical and angiographic characteristics and 30-day and 1-year outcomes were evaluated. Patients with previous CABG were significantly older and had a higher incidence of diabetes, hypertension, and hypercholesterolemia. They had a lower left ventricular ejection fraction and were also more likely to have congestive heart failure. After 1 year of follow-up, adverse cardiac events (death, MI, CABG, or repeat PCI) were significantly greater in patients with prior CABG (49.2% vs 35.9%, P =.04). With use of multivariate logistic regression analysis to adjust for differences in baseline characteristics, the treatment of vein graft was independently associated with adverse cardiac events (relative risk 1.48 [95% confidence interval 1.07-2.03], P =.02), but a history of prior CABG itself was not (relative risk 1.22 [95% confidence interval 0.96-1.56], P =.11).

CONCLUSIONS

Primary PCI for AMI in patients with previous CABG is associated with higher adverse events largely attributable to adverse baseline clinical characteristics and the treatment of a vein graft.

Does the presence of thrombus seen on a coronary angiogram affect the outcome after percutaneous coronary angioplasty? An Angiographic Trials Pool data experience

OBJECTIVES

This study aimed to determine whether pre-existing angiographic thrombus was associated with adverse in-hospital and six-month outcomes after percutaneous coronary interventions.

BACKGROUND

There are conflicting data about whether pre-existing thrombus is an independent predictor of adverse in-hospital and short-term outcome after coronary interventions.

METHODS

The Angiographic Trials Pool, a data set derived from eight prospective randomized trials, was analyzed. The study population consisted of 7,917 patients who underwent coronary interventions between 1986 and 1995. Two trials were excluded because they did not collect information regarding thrombus. Patients from the other six trials were divided on the basis of the presence or absence of thrombus.

RESULTS

In patients with (n = 2,752) and without (5,165) thrombus, in-hospital mortality following angioplasty was low (0.8 vs. 0.6%, p = 0.207). Several adverse outcomes were higher in patients with thrombus: death/myocardial infarction (8.4 vs. 5.5%, p < or = 0.001), in-hospital abrupt closure (5.9 vs. 3.9%, p < or = 0.001) and an in-hospital composite of death, myocardial infarction and/or repeat revascularization (15.4 vs. 11.2%, p < or = 0.001). Six-month mortality was low and comparable between the two groups (2.1 vs. 1.8%, p = 0.34), but the incidence of six-month death/myocardial infarction was higher in patients with thrombus (11.7 vs. 8.7%, p < or = 0.0001).

CONCLUSIONS

Percutaneous coronary angioplasty can be performed with low mortality in patients with pre-existing thrombus, although these patients are at higher risk of in-hospital and six-month death/myocardial infarction. Continued efforts are required to optimize the outcome in these high risk patients.

Clinical and angiographic outcome in the laser angioplasty for restenotic stents (LARS) multicenter registry

In-stent restenosis (ISR), when treated with balloon angioplasty (PTCA) alone, has an angiographic recurrence rate of 30%-85%. Ablating the hypertrophic neointimal tissue prior to PTCA is an attractive alternative, yet the late outcomes of such treatment have not been fully determined. This multicenter case control study assessed the angiographic and clinical outcomes of 157 consecutive procedures in 146 patients with ISR at nine institutions treated with either PTCA alone (n = 64) or excimer laser assisted coronary angioplasty (ELCA, n = 93)) for ISR. Demographics were similar except more unstable angina at presentation in ELCA-treated patients (74.5% vs. 63.5%; P = 0.141). Lesions selected for ELCA were longer (16.8 +/- 11.2 mm vs. 11.2 +/- 8.6 mm; P < 0.001), more complex (ACC/AHA type C: 35.1% vs. 13.6%; P < 0.001), and with compromised antegrade flow (TIMI flow < 3: 18.9% vs. 4.5%; P = 0.008) compared to PTCA-treated patients. ELCA-treated patients had similar rate of procedural success [93 (98.9% vs. 62 (98.4%); P = 1.0] and major clinical complications [1 (1.1%) vs. 1 (1.6%); P = 1.0]. At 30 days, repeat target site coronary intervention was lower in ELCA-treated patients (1.1% vs. 6.4% in PTCA-treated patients; P = 0.158), but not significantly so. At 1 year, ELCA-treated patients had similar rate of major cardiac events (39.1% vs. 45.2%; P = 0.456) and target lesion revascularization (30.0% vs. 32.3%; P = 0.646). These data suggest that ELCA in patients with complex in-stent restenosis is as safe and effective as balloon angioplasty alone. Despite higher lesion complexity in ELCA-treated patients, no increase in event rates was observed. Future studies should evaluate the relative benefit of ELCA over PTCA alone for the prevention of symptom recurrence specifically in patients with complex in-stent restenosis.

Glycemic control and outcome of diabetic patients after successful percutaneous coronary revascularization

OBJECTIVE

Our purpose was to examine whether the outcome of diabetic patients after successful percutaneous coronary revascularization (PCR) is influenced by the degree of control of hyperglycemia at the time of revascularization.

BACKGROUND

Diabetic patients have a worse outcome after PCR.

METHODS

We examined whether the degree of glycemic control (HbA(1c) levels) affected the occurrence of all-cause death and death/myocardial infarction among diabetic patients after successful PCR from October 1979 through December 1998. HbA(1c) was analyzed both as a continuous and a categorical variable (good [HbA(1c) <8.0%, n = 700], moderate [8.0% < or = HbA(1c) < or =10%, n = 442], or poor [HbA(1c) >10%, n = 231] control).

RESULTS

HbA(1c) levels were determined at a median (25th, 75th interquartiles) of 3 (1, 10) days after the index procedure for patients with good control, 2 (1, 7) days for moderate control, and 2 (1, 6) days for poor control. Median follow-up after successful PCR was 3.2 (1.2, 6.1) years, 3.9 (1.7,6.3) years, and 4.7 (2.1, 7.1) years, respectively. HbA(1c) as a continuous variable did not have an impact on either death (hazard ratio [95% confidence interval] 1.04 [0.98-1.10]) or death/myocardial infarction (1.02 [0.98-1.07]). As a categorical variable, patients with moderate and poor control had a similar hazard of death (0.99 [0.78-1.26] and 1. 14 [0.86-1.52], respectively) and death/myocardial infarction (1.01 [0.82-1.24] and 1.12 [0.87-1.45], respectively) relative to those with good control.

CONCLUSIONS

The degree of glycemic control among diabetic patients at the time of their index intervention did not have an impact on long-term outcomes after successful PCR.

Immediate and one-year outcome of intracoronary stent implantation in small coronary arteries with 2.5-mm stents

BACKGROUND

The role of coronary stenting in the treatment of stenoses in small coronary arteries with use of 2.5-mm stents is not well defined.

METHODS AND RESULTS

Between January 1995 and August 1999, 651 patients with stenoses in small coronary arteries were treated with 2.5-mm stents (n = 108) or 2.5-mm conventional balloon angioplasty (BA) (n = 543). Patients who received treatment with both 2.5-mm and > or =3.0-mm stent placement or balloons were excluded. Procedural success and complication rates as well as 1-year follow-up outcomes were examined. Baseline clinical characteristics were similar between the two groups, except patients in the stent group were more likely to have hypertension and a family history of coronary artery disease and less likely to have prior myocardial infarction. Angiographic success rates were higher in the stent group (97.2% vs 90.2%, P =.02). In-hospital complication rates were comparable between the two groups. Among successfully treated patients, 1-year follow-up revealed no significant differences in the survival (96.2% vs 95.2%, P =.89) or the frequency of Q-wave myocardial infarction (0% vs 0.4%, P =.60) or coronary artery bypass grafting (8.4% vs 6.8%, P =.89) between the stent and BA groups, respectively. However, patients in the stent group were more likely to have adverse cardiac events (35.4% vs 22.1%, P =.05). Stent use after excluding GR II stent use, however, was not independently associated with reduced cardiac events at follow-up (relative risk 1. 3 [95% confidence interval 0.8-2.3], P =.30).

CONCLUSIONS

Intracoronary stent implantation of stenoses in small coronary arteries with 2.5-mm stents can be carried out with high success and acceptable complication rates. However, compared with BA alone, stent use was not associated with improved outcome through 1 year of follow-up.

Asymptomatic occlusion of the left main coronary artery by an aortic pseudoaneurysm

Extrinsic compression of the left main coronary artery is a rare cause of coronary ischemia. We describe a 35-year-old Asian woman with complete asymptomatic occlusion of the left main coronary artery by a large aortic pseudoaneurysm. She underwent repair of the pseudoaneurysm and coronary artery bypass grafting at the Mayo Clinic in Rochester, Minn. The differential diagnosis is discussed. Based on this patient's age and associated vascular lesions, we conclude that Takayasu arteritis was the most likely cause of her condition.

Improving outcome over time of percutaneous coronary interventions in unstable angina

OBJECTIVE

This study was performed to evaluate the recent changes in the outcome of coronary interventions in patients with unstable angina (UA).

BACKGROUND

An early invasive strategy has not been shown to be superior to conservative treatment in patients with UA. Earlier studies had utilized older technology. Interventional approaches have changed in the recent past, but to our knowledge, no large studies have addressed the impact of these changes on the outcome of coronary interventions.

METHODS

We analyzed the in-hospital and intermediate-term outcome in 7,632 patients with UA who underwent coronary interventions in the last two decades. The study population was divided into three groups: group 1, n = 2,209 who had coronary intervention from 1979 to 1989; group 2, n = 2,212 with interventions from 1990 to 1993; and group 3, n = 3,211 treated from 1994 to 1998.

RESULTS

Group 2 and 3 patients were older and sicker compared with group 1 patients. The clinical success improved significantly in group 3 (94.1%) compared with group 2 (87%) and group 1 (76.5%) (p < 0.001). There was a significant reduction in in-hospital mortality, Q-wave myocardial infarction and need for emergency bypass surgery in group 3 compared with the earlier groups. One-year event-free survival was also significantly higher in the recent group compared with the earlier groups: 77% in group 3, 70% in group 2 and 74% in group 1 (p < 0.001). With the use of multivariate models to adjust for clinical and angiographic variables, treatment during the most recent era was found to be independently associated with improved in-hospital and intermediate-term outcomes.

CONCLUSIONS

There has been significant improvement in the in-hospital and intermediate-term outcome of coronary interventions in patients with UA in recent years; newer trials comparing conservative and invasive strategies are therefore needed.

Application of the New York State PTCA mortality model in patients undergoing stent implantation

BACKGROUND

This study applied the New York State conventional coronary angioplasty (PTCA) model of clinical outcomes to evaluate whether it has relevance in the current era of stent implantation. The model was developed in 62 670 patients treated with conventional PTCA from 1991 to 1994 to risk adjust mortality and bypass surgery after PTCA. Since then, stents have become the dominant form of intervention. Whether that model remains relevant is uncertain.

METHODS AND RESULTS

All patients undergoing stenting at the Mayo Clinic from 1995 to 1998 were analyzed for in-hospital mortality, bypass surgery performed after attempted stenting, and longer-term mortality. No patients were excluded. The New York model was used to risk adjust and predict in-hospital and follow-up mortality. There were 3761 patients with 4063 procedural admissions for stenting; 6,472 target vessel segments were attempted, and 96.1% of procedures were successful. With the New York multivariable risk factor equation, 79 in-hospital deaths were expected (1.95%); 66 deaths (1.62%) were observed. The New York model risk score in a logistic regression model was the most significant factor associated with in-hospital mortality (OR, 1.86; P<0.001). During a mean follow-up of 1.2+/-1.0 years, there were 154 deaths. Multivariable analysis documented 6 factors associated with subsequent mortality; New York risk score was the most significant (chi(2)=16.64, P=0.0001).

CONCLUSIONS

Although the New York mortality model was developed in an era of conventional angioplasty, it remains relevant in patients undergoing stenting. The risk score derived from that model is the variable most significantly associated with not only in-hospital but also longer-term outcome.

Prediction of death after percutaneous coronary interventional procedures

BACKGROUND

The prediction and comparison of procedural death after percutaneous coronary interventional procedures is inherently difficult because of variations in case mix and practice patterns. The impact of modern, expanded patient selection criteria, and newer technologic approaches is unknown. Our objective was to determine whether a risk equation based on patient-related variables and derived from an independent data set can accurately predict procedural death after percutaneous coronary intervention in the current era.

METHODS AND RESULTS

An analysis was made of the Mayo Clinic Coronary Interventional Database January 1, 1995, to October 31, 1997. Expected mortality rate was calculated with the use of the New York State multivariate risk score. In 3387 patients, 3830 procedures (55.1% stents) were performed, with an expected mortality rate of 2.32% and observed mortality rate of 2.38% (P = not significant). The risk score derived from the New York multivariate model was highly predictive of death (chi-square = 213.8; P <.0001). The presence of a high-risk lesion characteristic such as calcium, thrombus, or type C lesion was modestly associated with death.

CONCLUSIONS

The New York State multivariate model accurately predicted procedural death in our database.

Stable Angina Pectoris

Patients with stable Canadian Heart Classification I or II angina pectoris may be managed successfully with a conservative medical program. Such a program should always include aspirin, beta-blocking agents, and lipid-lowering therapies unless contraindications to them exist. Exercise and dietary restrictions will achieve target lipid values in some patients; the remainder should be treated with a lipid-lowering drug if they are at high risk of cardiac events. Emerging data support a role for angiotensin-converting enzyme inhibitors in many, if not all, patients with coronary artery disease. The role of calcium antagonists in this population remains uncertain, with some favorable and some unfavorable effects seen with these agents. High-risk patients and those with a desire to achieve greater exercise tolerance once medical therapies have been optimized are suitable candidates for angiographic study and revascularization. Although randomized studies addressing this population are limited, available data support the benefits of either coronary artery bypass grafting or percutaneous catheter intervention.

Immediate and long-term outcome of intracoronary stent implantation for true bifurcation lesions

OBJECTIVES

The aim of this study was to evaluate the immediate and long-term outcome of intracoronary stent implantation for the treatment of coronary artery bifurcation lesions.

BACKGROUND

Balloon angioplasty of true coronary bifurcation lesions is associated with a lower success and higher complication rate than most other lesion types.

METHODS

We treated 131 patients with bifurcation lesions with > or =1 stent. Patients were divided into two groups; Group (Gp) 1 included 77 patients treated with a stent in one branch and percutaneous transluminal coronary angioplasty (PTCA) (with or without atherectomy) in the side branch, and Gp 2 included 54 patients who underwent stent deployment in both branches. The Gp 2 patients were subsequently divided into two subgroups depending on the technique of stent deployment. The Gp 2a included 19 patients who underwent Y-stenting, and Gp 2b included 33 patients who underwent T-stenting.

RESULTS

There were no significant differences between the groups in terms of age, gender, frequency of prior myocardial infarction (MI) or coronary artery bypass grafting (CABG), or vessels treated. Procedural success rates were excellent (89.5 to 97.4%). After one-year follow-up, no significant differences were seen in the frequency of major adverse events (death, MI, or repeat revascularization) between Gp 1 and Gp 2. Adverse cardiac events were higher with Y-stenting compared with T-stenting (86.3% vs. 30.4%, p = 0.004).

CONCLUSIONS

Stenting of bifurcation lesions can be achieved with a high success rate. However, stenting of both branches offers no advantage over stenting one branch and performing balloon angioplasty of the other branch.

Immediate and late outcomes after direct stent implantation without balloon predilation

OBJECTIVES

The aim of our study was to compare the in-hospital and long-term clinical outcomes of direct coronary stenting with balloon predilation followed by stent placement.

BACKGROUND

With improvement in stent designs, the practice of direct stenting without balloon predilation has become more widespread.

METHODS

We analyzed the Mayo Clinic Coronary Intervention data base between January 1, 1995 and March 5, 1999 and identified 777 patients who were treated with direct stenting (DS) and 3,176 patients treated with balloon angioplasty plus stenting (BA+S).

RESULTS

The procedural success rates between the DS and BA+S groups were not significantly different (96.3% vs. 96.4%). The ability to deliver the stent in a subgroup of patients who had DS was 95%, with 5% requiring crossover to predilation. Multivariate analysis showed no significant differences with respect to in-hospital death (odds ratio [OR] 0.9, 95% confidence interval [CI] 0.5 to 1.8), in-hospital myocardial infarction (OR 0.9, 95% CI 0.6 to 1.2) or revascularization (OR 0.7, 95% CI 0.4 to 1.5) in the DS compared with the BA+S group. Long-term outcomes were not significantly different between the DS and BA+S groups. The procedural duration was significantly shorter in the DS group, and there was a decreased utilization of contrast agent, balloons and wires.

CONCLUSIONS

The in-hospital and long-term clinical outcomes in patients undergoing a coronary intervention are equivalent when comparing stenting without balloon predilation with balloon angioplasty followed by stenting. Direct stenting is associated with decreased utilization of contrast agent and equipment and shorter procedure times. A randomized study should be performed to better determine the impact of this technique on short- and long-term procedural outcomes.

Effect of age on the outcome of angioplasty for acute myocardial infarction among patients treated at the Mayo Clinic

PURPOSE

Elderly patients, especially those 80 years of age and older, have been excluded from most studies of thrombolysis or primary coronary angioplasty in patients with acute myocardial infarction. We compared the outcomes of elderly patients who underwent coronary angioplasty with the outcomes of younger patients and determined whether there were any temporal trends in survival.

PATIENTS AND METHODS

We reviewed the outcomes of 1,597 consecutive patients who underwent primary coronary angioplasty between 1979 and 1997, including 127 patients who were 80 years of age or older (mean [+/-SD] age, 83 +/- 3 years, 47% male). Their in-hospital and long-term outcomes were compared with those of 524 patients who were 70 to 79 years old, 527 patients who were 60 to 69 years old, and 419 patients who were 50 to 59 years old. The oldest group of patients was divided into two groups, based on whether they had intervention through the end of 1993 (n = 56) or between 1994 and 1997 (n = 71). The survival rate of the patients who had no complications and left the hospital was compared with expected survival based on age- and sex-adjusted data.

RESULTS

Patients 80 years of age or older had more adverse baseline characteristics, including risk factors and comorbid conditions, than the younger patients. The clinical success rate of primary angioplasty in this group was lower than those in the other three groups (61% versus 74% in those aged 70 to 79 years, 73% in those aged 60 to 69 years, and 81% in those aged 50 to 59 years, P < 0.001). The in-hospital mortality rate among patients 80 years of age or older was significantly greater than among patients in the other three groups (21% in those aged 80 years or older, 13% in those aged 70 to 79 years, 9% in those aged 60 to 69 years, and 4% in those aged 50 to 59 years, P < 0.001 ). The clinical success rate of the angioplasty improved significantly in the more recent period (75% versus 45%, P = 0.0006) and in-hospital mortality declined (16% versus 29%, P = 0.07). During follow-up, mortality in the oldest age group in whom angioplasty was successful was significantly greater than in the three younger groups, but was similar to the expected survival in the general US population.

CONCLUSIONS

The mortality associated with primary angioplasty for acute myocardial infarction in octogenarians remains high, although there has been significant improvement in the clinical success rate. The long-term prognosis following a successful angioplasty is not different from that in an age- and sex-adjusted U.S. white population.

Clinical outcome after multivessel coronary stent implantation

BACKGROUND

Percutaneous transluminal coronary angioplasty (PTCA) has been shown to be an effective therapy for multivessel coronary artery disease, although more frequent acute complications and an increased need to repeat revascularization than with single-vessel PTCA continue to be limitations. Intracoronary stent placement has been shown to reduce the rate of acute complications and the need for subsequent revascularization. We sought to evaluate the outcome among patients undergoing successful multivessel coronary intervention with stents.

METHODS

The participants were 175 patients without coronary artery bypass grafts who underwent multivessel coronary revascularization in which stent placement was attempted in all treated segments from January 1992 through March 1998 at our institution. Clinical and angiographic characteristics and outcomes were analyzed.

RESULTS

Stent placement was attempted for 428 coronary lesions. The angiographic success rate was 100%. Modified American College of Cardiology-American Heart Association type B2 and C lesions accounted for 74.5% of the lesions. Three patients (1.7%) died in the hospital. No patient had Q-wave myocardial infarction or needed coronary artery bypass grafting. Procedural success was achieved for 172 patients (98.3%). The Kaplan-Meier probability of freedom from death or myocardial infarction at 12 months was 96.6%, of any revascularization was 81. 7%, and of death, myocardial infarction, and any revascularization combined was 79.8%. The use of long-acting nitrates at 12 months was reduced (34.3% versus 19.1%, P =.01).

CONCLUSIONS

Multivessel coronary stent placement is associated with an excellent procedural success rate despite a high rate of adverse lesion characteristics and a high event-free survival rate during the follow-up period. The likelihood that revascularization will not have to be repeated during the first follow-up year is significantly better than that for historic controls of multivessel PTCA.

Staphylococcus lugdunensis endocarditis: a complication of vasectomy?

Three cases of Staphylococcus lugdunensis endocarditis have been reported in patients with a history of vasectomy preceding the development of endocarditis. We describe a new case of a 39-year-old man who developed infective endocarditis due to S. lugdunensis after vasectomy. He was successfully treated with a 7-week course of intravenous antibiotics and subsequently underwent mitral valve reconstruction for severe mitral regurgitation. The present case further supports an association between vasectomy and S. lugdunensis endocarditis.

Baseline clinical and angiographic variables associated with long-term outcome after successful intracoronary stent implantation

Although randomized studies have demonstrated improved outcomes with stents over balloon angioplasty in straightforward coronary narrowings in low-risk patients, this advantage is less clear for complex lesions and high-risk patients. This study was designed to identify clinical and angiographic variables that are associated with long-term outcome after stent implantation. We identified 1,709 patients undergoing successful stent placement without in-hospital major adverse events. We analyzed clinical, lesional, and procedural variables to determine their correlation with outcome. Mean duration of follow-up was 1.6 +/- 1.4 years. Cox proportional-hazards models and stepwise methods were used to assess which covariates were potentially related to each end point. The occurrence of death/myocardial infarction (MI) was associated with any history of congestive heart failure (relative risk [RR] 3.3, 95% confidence interval [CI] 2.3 to 4.7, p <0.0001), procedure within 24 hours of MI (RR 2.3, CI 1.3 to 4.1, p = 0.0048), vein graft intervention (RR 1.8, CI 1.3 to 2.6, p = 0.0007), and prior MI (RR 1.8, CI 1.2 to 2.6, p = 0.004). Repeat revascularization was associated with multivessel stent placement (RR 1.8, CI 1.2 to 2.8, p = 0.006) and stent for abrupt closure (RR 1.7, CF 1.1 to 2.7, p = 0.03), but was less frequent with de novo lesions and right coronary artery lesions (RR 0.6, CI 0.5 to 0.8, p = 0.0007, and RR 0.8, CI 0.6 to 1.0, p = 0.05, respectively). The cumulative end point of death/MI/repeat revascularization was associated with congestive heart failure (RR 1.7, CI 1.3 to 2.2, p <0.0001), multivessel stent placement (RR 1.6, Cl 1.1 to 2.3, p = 0.03), warfarin therapy (RR 1.4, CI 1.2 to 1.8, p = 0.001), and procedure within 24 hours of MI (RR 1.5, CI 1.1 to 2.1, p = 0.02), but was less frequent with complete revascularization and right coronary artery intervention (RR 0.8, CI 0.7 to 0.99, p = 0.04, and RR 0.7, CI 0.6 to 0.9, p = 0.009, respectively). Thus, this study demonstrates that there are readily identifiable characteristics in patients treated successfully with stents that are associated with long-term outcome.

The influence of abciximab use on clinical outcome after aortocoronary vein graft interventions

OBJECTIVES

The purpose of this study was to evaluate the effect of abciximab use on clinical outcome in aortocoronary vein graft interventions.

BACKGROUND

Although large randomized trials have demonstrated a significant benefit of abciximab use in the setting of percutaneous coronary interventions, there is relatively little data with respect to the use of this agent in percutaneous vein graft interventions.

METHODS

Three hundred and forty-three patients were identified; 210 undergoing vein graft intervention without abciximab and 133 patients with abciximab.

RESULTS

There were differences in baseline clinical and angiographic characteristics between the two groups; advanced age, unstable angina, older vein grafts and thrombus containing lesions were relatively common in both groups. Angiographic and procedural success rates were similar with or without the use of abciximab (89% vs. 92%, p = 0.15, and 85% vs. 91%, p = 0.12, respectively). The in-hospital composite end point of death/Q-wave myocardial infarction (QWMI)/repeat revascularization was similar between the two groups. Utilizing statistical modeling to adjust for baseline differences between the groups, abciximab use did not influence the cumulative long-term composite end point of death/MI/repeat revascularization.

CONCLUSIONS

This study demonstrates that in this relatively high-risk population undergoing aortocoronary vein graft interventions, the administration of abciximab periprocedurally does not appear to reduce major adverse clinical events.

Clinical, angiographic, and procedural correlates of abrupt vascular closure during coronary intervention: a 10-year experience at Mayo Clinic

A large matched-cohort study was carried out to determine correlates of in-hospital abrupt vascular closure (AC). Univariate analysis identified current cigarette smoking (P = 0.021), myocardial infarction within 24 hr prior to procedure (P = 0.0035), emergency procedure (P = 0.02), lesion thrombus (P = 0.0001), and lesion angulation (P = 0.021) as significant clinical and angiographic variables. Relative to balloon angioplasty (PTCA), use of atherectomy (P = 0.015) and laser devices (P = 0.018) but not elective stent placement (P = 0.97) were associated with increased risk of AC. In the multivariate model, current cigarette smoking (P = 0.0474), lesion thrombus (P = 0.0001), lesion angulation (P = 0.0124), use of atherectomy devices (P = 0.001), and laser devices (P = 0.0037) remained as significant correlates of increased AC events. In conclusion, the risk of AC appears associated primarily with lesion characteristics and use of nonballoon devices other than stents. Elective stent placement did not appear to reduce AC risk over conventional PTCA; the small number of patients studied may have prevented any benefit from being observed.

Smoking status and outcome after primary coronary angioplasty for acute myocardial infarction

BACKGROUND

Because of the increased propensity of intracoronary thrombi to form in cigarette smokers, percutaneous transluminal angioplasty (PTCA) for acute myocardial infarction (AMI) may be less effective in smokers. We sought to determine the impact of smoking status on outcome after PTCA for AMI.

METHODS

Patients enrolled in the GUSTO IIb Angioplasty Substudy were randomly assigned to receive PTCA or tissue-plasminogen activator (tPA) for AMI. The interaction of smoking status (nonsmokers = 344, former smokers = 294, current smokers = 490) and treatment strategy with the occurrence of death, nonfatal reinfarction, or nonfatal, disabling stroke at 30 days was analyzed. Procedural success (residual stenosis <50% and Thrombolysis in Myocardial Infarction [TIMI] flow grade 3) was also analyzed for patients who underwent PTCA (n = 444).

RESULTS

Among patients who underwent PTCA, nonsmokers had worse percent stenosis of the culprit lesion before reperfusion (P =.03) and more often had TIMI flow grade 0 (P <.05). Procedural success was more common in smokers (65.6%) than in former smokers (53.3%) and nonsmokers (52. 4%; P =.02), reflecting a higher rate of postprocedure TIMI 3 flow. PTCA was associated with a better 30-day outcome than tPA for current smokers (odds ratio [95% confidence interval] = 0.41 [0.19 to 0.88]), with a similar trend for former smokers (0.73 [0.34 to 1. 58]) and nonsmokers (0.77 [0.42 to 1.40]). At 6 months, smokers randomly assigned to PTCA also had fewer deaths and reinfarction (0. 58 [0.31 to 1.07]).

CONCLUSIONS

Although smoking status affects angiographic variables before and after PTCA for AMI, PTCA is associated with a better 30-day outcome than tPA regardless of smoking status and should be considered when readily available.

Sulfonylurea drugs increase early mortality in patients with diabetes mellitus after direct angioplasty for acute myocardial infarction

OBJECTIVES

The purpose of this study was to examine the impact of sulfonylurea drug use on outcome in diabetic patients undergoing direct coronary angioplasty for acute myocardial infarction.

BACKGROUND

Sulfonylurea drugs impair ischemic preconditioning. Whether sulfonylurea drugs affect outcome adversely in diabetic patients undergoing direct angioplasty for acute myocardial infarction is unknown.

METHODS

Clinical outcomes after direct balloon angioplasty for acute myocardial infarction were evaluated in 67 diabetic patients taking oral sulfonylurea drugs and 118 diabetic patients not taking these drugs.

RESULTS

Hospital mortality was significantly higher among diabetics treated with sulfonylurea drugs at the time of myocardial infarction (24% vs. 11%). Univariate analysis identified sulfonylurea drug, age, ventricular function, ejection fraction less than 40%, prior bypass surgery and congestive heart failure as correlates of increased in-hospital mortality. Logistic regression found sulfonylurea drug use (odds ratio 2.77, p=0.017) to be independently associated with early mortality. Congestive heart failure, but not sulfonylurea drug use, was associated with an increased incidence of in-hospital ventricular arrhythmias. Congestive heart failure, prior bypass surgery and female gender, but not sulfonylurea drug use, were associated with late adverse events.

CONCLUSIONS

Sulfonylurea drug use is associated with an increased risk of in-hospital mortality among diabetic patients undergoing coronary angioplasty for acute myocardial infarction. This early risk is not explained by an increase in ventricular arrhythmias, but may reflect deleterious effects of sulfonylurea drugs on myocardial tolerance for ischemia and reperfusion. For surviving patients sulfonylurea drug use is not associated with an increased risk of serious late adverse events.

Abciximab administration and outcome after intracoronary stent implantation

Although adjunctive abciximab therapy improves outcome after angioplasty or atherectomy, there are few data demonstrating its benefit for intracoronary stent implantation. We characterized patients receiving abciximab for stent placement in our practice and determined the impact of abciximab on outcome. Abciximab was introduced to our practice in April 1995 for percutaneous revascularization. Demographic, clinical, and angiographic variables that were independently associated with the use of abciximab for stent placement through 1996 (abciximab era) were examined. We then examined among all patients receiving stents from 1992 through 1996 (preabciximab and abciximab eras) whether the use of abciximab was independently associated with improved outcome (death, nonfatal Q-wave myocardial infarction, coronary bypass surgery, or target vessel percutaneous revascularization) in the hospital and at 30 days. The 30-day event rate was 7% for those who did or did not receive abciximab. The following characteristics were independently associated with the use of abciximab for stent placement in the abciximab era: thrombus before stent placement (chi-square 50.5), > or =2 stents implanted (chi-square 10.8), stent in venous graft (chi-square 7.4), calcific lesion (chi-square 5.8), and hypertension (chi-square 5.5). Among all patients receiving stents in the preabciximab and abciximab eras (n=1,859), the presence of these characteristics was independently associated with worse outcome. Abciximab, however, did not improve outcome in the hospital (odds ratio [95% confidence interval]=0.96 [0.58 to 1.58]) or at 30 days (0.87 [0.53 to 1.41]), even after adjusting for these characteristics. Abciximab for stent placement was used in high-risk patients in our practice but was not associated with improved outcome.

Intravenous adenosine and lidocaine in patients with acute myocardial infarction

OBJECTIVES

A pilot study was designed to assess the safety of combined intravenous adenosine and lidocaine in patients with acute myocardial infarction and to estimate the likelihood of a beneficial effect on final infarct size.

BACKGROUND

Adenosine plus lidocaine reduces infarct size in animals, but the safety and efficacy in human beings is unknown.

METHODS AND RESULTS

Adenosine (70 microg/kg per minute intravenous infusion) plus lidocaine (1 mg/kg intravenous bolus injection and 2 mg/kg per minute infusion) was given to 45 patients with acute myocardial infarction. Patients underwent immediate balloon angioplasty without preceding thrombolytic therapy. Myocardial perfusion defects were measured with serial technetium 99m sestamibi studies. One patient developed persisting hypotension in conjunction with a large inferolateral myocardial infarction. Transient hypotension in three other patients resolved with a reduction in adenosine. Advanced atrioventricular block was never observed. Other adverse events (including atrial fibrillation, ventricular tachyarrhythmia, bradycardia, and respiratory distress) occurred at low frequencies, as expected for patients with acute myocardial infarction. An initial median perfusion defect of 45% of the left ventricle (60% for anterior infarction, 17% for nonanterior infarction) was observed. At hospital discharge (mean +/- SD = 4.3 +/- 2.1 days) the median value was 12%, and at 8 +/- 4 weeks it was 3% (7% for anterior infarction, 0% for nonanterior infarction); 14 patients had no measurable follow-up. Compared with historical control patients, prehospital discharge measurements were not different but late perfusion defects were improved.

CONCLUSIONS

Treatment with intravenous adenosine and lidocaine during acute myocardial infarction has sufficient safety and potential for improved myocardial salvage. Randomized studies are justified.

Rotational atherectomy for bifurcation lesions of the coronary circulation: technique and initial experience

Bifurcation lesions of the coronary circulation are difficult to treat with standard balloon technology and are associated with relatively low procedural success rates and high complication rates. We hypothesized that effective debulking of bifurcation lesions with rotational atherectomy would improve observed results. Fifteen patients underwent rotational atherectomy of such lesions. Both limbs of the bifurcation were rotablated in seven patients and one limb in eight; seven patients also underwent stent deployment. Successful angiographic results were obtained in all limbs (<30% residual stenoses). One patient had a non-Q-wave myocardial infarction. No other significant complications occurred. We conclude that rotablation of bifurcation coronary stenoses is feasible, safe, and associated with a high likelihood of angiographic success.

Clinical outcome of patients undergoing multivessel coronary stent implantation

OBJECTIVES

To evaluate the outcome of patients undergoing multivessel coronary stent implantation.

BACKGROUND

Percutaneous transluminal coronary angioplasty has been shown to be an effective treatment for multivessel coronary artery disease, although the need for repeat revascularization continues to be a limitation. Intracoronary stent placement has been shown to reduce the need for subsequent revascularization.

METHODS

Seventy-seven patients without prior coronary artery bypass grafting (CABG) undergoing multivessel coronary revascularization in which stents were placed in all treated segments over a 5 year period at our institution were identified. Clinical and angiographic characteristics and outcomes were analyzed.

RESULTS

One hundred and eighty-eight coronary lesions were successfully treated (2.1+/-0.3 treated vessels/patient, 2.4+/-0.6 treated lesions/patient) using 2.8+/-1.2 stents/patient (range 2-9) and 1.4+/-0.8 stents/vessel (range 1-6). Procedural success rate [angiographic success without in-hospital death, Q-wave myocardial infarction (Q-wave MI) or CABG] was achieved in 76 of 77 patients (98.7%). Anatomically complete revascularization was achieved in 46 (59.7%) patients. Modified ACC/AHA Type B2 and C lesions comprised 75.5% of the 188 lesions. The left anterior descending artery was treated in 57 (74.0%) patients. The indication for stent placement was dissection or threatened/abrupt closure in 54 segments (28.8%). In-hospital events included death in one patient (1.3%); no patient suffered a Q-wave MI or required CABG. Stent occlusion occurred in two (2.6%) patients, and repeat percutaneous intervention of the target vessel was also required in these two patients. Any of these adverse events occurred in three (3.9%) patients. No further events occurred after hospital discharge in the 30 days after the procedure. Of hospital survivors (n=76), adverse events at 6 months included death in two patients (2.6%), MI in two (2.6%), CABG in six (7.9%); nine (11.8%) patients underwent repeat percutaneous intervention and 15 (19.7%) underwent any revascularization.

CONCLUSIONS

Multivessel coronary stent placement is associated with an excellent procedural success rate despite a high rate of adverse lesion characteristics, and a low rate of death or MI during follow-up. The need for further revascularization compares favorably with published rates with multivessel PTCA and single stent implantation for discrete de novo lesions.

Predictors of smoking cessation after percutaneous coronary revascularization

OBJECTIVE

To identify factors predictive of smoking cessation after successful percutaneous coronary revascularization.

MATERIAL AND METHODS

We undertook a case-control study of the smoking status of all patients at Mayo Clinic Rochester from September 1979 through December 1995 who were smokers at the time of an index percutaneous coronary revascularization procedure in the non-peri-infarction setting (no myocardial infarction within 24 hours). Maximal duration of prospective follow-up was 16 years. Patients were classified into those who permanently quit smoking immediately after the procedure (N = 435; mean follow-up, 5.1 +/- 3.7 years) or those who continued to smoke at some time during follow-up (N = 734; mean follow-up, 5.3 +/- 3.7 years). Logistics regression models were formulated to determine independent predictors of smoking cessation.

RESULTS

Predictors of continued smoking were greater prior cigarette consumption (odds ratio [OR] = 1.009 for each pack-year; 95% confidence interval [CI] = 1.004 to 1.014) and having one or more risk factors for coronary artery disease other than cigarette smoking (OR = 1.49; 95% CI = 1.15 to 1.93). Older age (OR = 0.98 for each additional year; 95% CI = 0.97 to 0.99) and unstable angina at time of initial assessment (OR = 0.69; 95% CI = 0.52 to 0.91) were associated with less likelihood of continued smoking.

CONCLUSION

Younger patients with a worse risk profile and greater prior cigarette consumption were more likely than other patients to continue smoking after percutaneous coronary revascularization in the non-peri-infarction setting. Patients who had unstable angina were more likely to quit smoking than those who had stable angina. Despite the proven benefits of smoking cessation after percutaneous coronary revascularization, a substantial proportion of smokers (63%) continue to smoke; thus, smoking-cessation counseling should be addressed in this population.

Clinical outcome of patients undergoing endoluminal coronary artery reconstruction with three or more stents

OBJECTIVES

We sought to evaluate the outcome of patients undergoing multiple (three or more), contiguous stent implantation within a single native coronary artery.

BACKGROUND

The implantation of multiple stents within a single coronary artery is increasing in frequency, although the outcome of such patients is not well described.

METHODS

Forty-five patients without previous coronary artery bypass graft surgery (CABG) undergoing multiple, contiguous stent implantation in a single coronary artery were identified. Clinical and angiographic characteristics and outcomes were analyzed.

RESULTS

The angiographic success rate was 97.8%. The procedural success rate was 91.1%; stent occlusion during the initial hospital period occurred in four patients (8.9%). Death, myocardial infarction (MI), CABG, repeat target vessel intervention or severe angina occurred in 10 (23.3%) of 43 hospital survivors at 6-months follow-up. The indication for stent placement was threatened or abrupt closure in 30 patients (66.7%). Of the 25 patients with abrupt or threatened closure whose clinical and angiographic data would have indicated emergent CABG had stents not been available, the frequency of in-hospital death and Q wave MI was similar to that of a matched consecutive series of patients at our institution who underwent emergent CABG after failed angioplasty. At 1 year, the frequency of death, Q wave MI, CABG and severe angina at 1 year was similar in the two groups; the need for repeat percutaneous intervention was more common in the stent group (25% vs. 0%, p = 0.01).

CONCLUSIONS

Implantation of multiple, contiguous intracoronary stents was associated with a high initial success rate, although the incidence of early stent closure was relatively high. Adverse events at 6 months of follow-up were more frequent than previously reported for elective single-stent implantation; however, adverse angiographic characteristics such as dissection and thrombus were frequent in this group. In addition, the strategy of multiple stent implantation in the setting of failed angioplasty is a reasonable alternative to emergent CABG, although the need for further percutaneous intervention must be anticipated.

Effect of infarct-related artery patency and late potentials on late mortality after acute myocardial infarction

OBJECTIVE

To assess the effect of patency of the infarct-related artery and the presence of late potentials on late cardiac mortality after myocardial infarction.

MATERIAL AND METHODS

We studied the influence of the infarct-related artery patency and the presence of late potentials during signal-averaged electrocardiography on late mortality in 124 survivors of acute myocardial infarction. In addition, we assessed predictive factors of cardiac mortality by univariate and multivariate statistical analysis.

RESULTS

A study group of 98 men and 26 women (mean age, 59 years) who were survivors of acute myocardial infarction underwent follow-up for a mean of 3.6 +/- 1.0 years. Immediate reperfusion therapy (thrombolysis or direct angioplasty) was accomplished in 71 patients (57%). During follow-up, 13 cardiac-associated deaths occurred. Infarct-related artery patency was strongly associated with improved survival, but the presence of late potentials did not correlate with increased mortality, even among patients with impaired left ventricular function. Univariate and multivariate analyses identified occluded infarct-related arteries, prior myocardial infarction, reduced left ventricular ejection fraction, and advanced age, but not late potentials, as predictors of increased late cardiac mortality.

CONCLUSION

These data suggest that coronary angiography may, but signal-averaged electrocardiography may not, identify patients with increased late risk of cardiac-related death after myocardial infarction. The low mortality among patients who have undergone successful reperfusion therapy may reduce the ability of noninvasive tests to distinguish between high- and low-risk patients.

Outcome > or = 10 years after successful percutaneous transluminal coronary angioplasty

Patients (n = 611) after successful percutaneous transluminal coronary angioplasty were prospectively followed over 10 to 16 years for major adverse events. The effect of gender, extent of coronary artery disease, left ventricular dysfunction, and age on occurrence of adverse events were analyzed in detail. The incidence of death, Q-wave myocardial infarction, and coronary bypass surgery was 23.1%, 3.9%, and 32.7%, respectively. Men and women had similar mortality (p = 0.13) and Q-wave myocardial infarction (p = 0.57), but men had more coronary bypass surgery (p = 0.06). Patients with multivessel disease had higher mortality (p < 0.0001), and patients with 3-vessel disease had a higher incidence of Q-wave myocardial infarction (p = 0.04) and coronary bypass surgery (p < 0.001). Left ventricular dysfunction was associated with higher mortality (p < 0.0001) and coronary bypass surgery (p = 0.045), but not Q-wave myocardial infarction (p = 0.99). Mortality was higher in elderly patients (p < 0.0001), but the incidence of Q-wave myocardial infarction was similar (p = 0.64). Older patients underwent coronary bypass surgery less often (p = 0.004). By multivariate analysis, only the extent of coronary disease (relative risk [RR] 1.71, confidence interval [CI] 1.34 to 2.19; p = 0.0001), diabetes mellitus (RR 1.82, CI 1.28 to 2.59; p = 0.001), hypertension (RR 1.30, CI 1.08 to 1.96, p = 0.009), male gender (RR 1.30, CI 0.99 to 1.71, p = 0.058), and prior myocardial infarction (RR 1.44, CI 1.14 to 1.81, p = 0.002) independently influenced the incidence of major adverse events. We conclude that it is possible to identify patients with worse long-term prognosis after percutaneous transluminal coronary angioplasty based on clinical and angiographic parameters.

Histologic correlates of angiographic chronic total coronary artery occlusions: influence of occlusion duration on neovascular channel patterns and intimal plaque composition

OBJECTIVES

Age-related changes in histologic composition and neovascular channel (NC) pattern of angiographic chronic total coronary artery occlusions (CTOs) were studied to define histologic correlates of age-related revascularization profiles and neovascular channel formation.

BACKGROUND

Revascularization of CTOs is frequently characterized by inability to cross or dilate the lesion and a high incidence of reocclusion or restenosis but low periprocedural ischemic complication rates. Little is known about the histopathologic basis of these observations.

METHODS

Ninety-six angiographic CTOs from autopsy studies in 61 patients who had undergone coronary angiography within 3 months of death were studied. Abrupt plaque rupture was excluded. Occlusion segments were analyzed for 1) histologic composition as a function of lesion age; and 2) NC pattern as a function of lesion age and intimal plaque (IP) composition.

RESULTS

Cholesterol and foam cell-laden IP was more frequent in younger lesions (p = 0.0007), whereas fibrocalcific IP increased with CTO age (p = 0.008). IP NCs arose directly from adventitial vasa vasorum and were anatomically and quantitatively related in terms of number and size (p = 0.0001) to the extent of IP cellular inflammation. IP cellular inflammation exceeded that found in the adventitia (p < 0.001) or media (p = 0.0001) across all CTO ages. In CTOs < 1 year old, the adventitia was associated with a larger number and size of NCs relative to the IP (p = 0.0006 and p = 0.009), media (p = 0.0001 and p = 0.002) and recanalized lumen (p = 0.0001 and p = 0.001). In CTOs >1 year old, the adventitia and IP NC numbers were similar and exceeded NC numbers found in the media (p = 0.0001) and recanalized lumen (p = 0.0001 and p = 0.003).

CONCLUSIONS

Angiographic CTO frequently corresponds to less than complete occlusion by histologic criteria. Age-related changes in IP composition from cholesterol laden to fibrocalcific may explain the adverse revascularization profile of older CTOs. IP NC growth derived from the adventitia increases with age and is strongly associated with IP cellular inflammation. IP NC formation may protect against the flow-limiting effects of IP growth.

The changing face of coronary interventional practice. The Mayo Clinic experience

BACKGROUND

Devices designed to facilitate or replace conventional percutaneous transluminal coronary angioplasty have been introduced in recent years.

OBJECTIVES

To characterize the changes in percutaneous coronary interventional practice over 16 years and to assess the relative use of these new devices.

METHODS

We performed a retrospective analysis of all patients who underwent percutaneous coronary revascularization at Mayo Clinic, Rochester, Minn, during a 16-year period (1980-1995) and characterized the changes in procedural and clinical factors.

RESULTS

The number of coronary interventional procedures performed increased from 38 in 1980 to 1284 in 1995. Atherectomy and laser angioplasty were incorporated in 1988; their use peaked in 1994 (17% of procedures) but decreased to 9.9% by 1995. In contrast, the use of intracoronary stents has increased steadily since 1990. By 1995, intracoronary stents were placed in 48.2% of procedures. The success rate improved from 55.3% in 1980 to 91.4% in 1995, although patients were older (51 +/- 10 [mean +/- SD] years in 1980 vs 63 +/- 12 years in 1995), had more extensive coronary artery disease (0% with multivessel disease in 1980 vs 47.4% in 1995), had more complex lesions, and often underwent intervention in the peri-infarction setting (2.6% of procedures in 1980 vs 17% in 1995). The rate of referral to emergency coronary bypass surgery after percutaneous procedures declined from 5.2% in 1980 to 0.4% in 1995.

CONCLUSIONS

Current coronary interventional practice is expanding and improving. In contrast to intracoronary stents that have greatly affected current practice, other new devices are used infrequently. Conventional angioplasty, with or without intracoronary stents, remains the dominant treatment strategy.

Effect of smoking status on the long-term outcome after successful percutaneous coronary revascularization

BACKGROUND

Cigarette smoking is known to be deleterious to patients with coronary artery disease, but the effect of smoking on the clinical outcome of percutaneous coronary revascularization is unknown.

METHODS

Patients who had undergone successful percutaneous coronary revascularization at the Mayo Clinic between 1979 and 1995 were divided into nonsmokers (n=2009), former smokers (those who had stopped smoking before the procedure, n=2259), quitters (those who stopped smoking after the procedure, n=435), and persistent smokers (those who smoked before and after the procedure, n=734).

RESULTS

The maximal follow-up was 16 years (mean [+/-SD], 4.5+/-3.4). The nonsmokers and former smokers had similar base-line characteristics and outcomes. The quitters and persistent smokers were younger than the nonsmokers and former smokers and had more favorable clinical and angiographic characteristics. In analyses adjusted for confounding base-line characteristics, the persistent smokers had a greater relative risk of death (1.76 [95 percent confidence interval, 1.37 to 2.26]) and of Q-wave infarction (2.08 [95 percent confidence interval, 1.16 to 3.72]) than the nonsmokers. The quitters and persistent smokers were less likely than the nonsmokers to undergo additional percutaneous coronary procedures (relative risk, 0.80 [95 percent confidence interval, 0.64 to 0.98] and 0.67 [95 percent confidence interval, 0.56 to 0.81], respectively) or coronary bypass surgery (relative risk, 0.72 [95 percent confidence interval, 0.54 to 0.95] and 0.68 [95 percent confidence interval, 0.54 to 0.86], respectively). The persistent smokers were also at greater risk for death than the quitters (relative risk, 1.44 [95 percent confidence interval, 1.02 to 2.11]).

CONCLUSIONS

Patients who continued to smoke after successful percutaneous coronary revascularization were at greater risk for Q-wave infarction and death than nonsmokers. The cessation of smoking either before or after percutaneous revascularization was beneficial. Patients undergoing percutaneous revascularization should be encouraged to stop smoking.

Interventional cardiology and intracoronary stents--a changing practice: approved vs. nonapproved indications

Our objective was to document change in stent usage in a single practice over time and to study "off-label" compared to Food and Drug Administration (FDA)-approved indications. Although only two intracoronary stents have been approved by the FDA, the relatively limited approved indications do not account for the dramatic increase in stent implantation. This increase has important implications for patient health care delivery. This study of stent usage in a single center over a 36-mo period included all patients treated with coronary stents at the Mayo Clinic from January 1993-December 1995, and evaluated the relative difference in frequency between "off-label" and FDA-approved indications for implantation. During the 36-mo period of study, 3,614 interventional procedures were done and one or more stents were placed in 25.4% of patients. The proportion of patients receiving stents increased throughout this time: during the first 6-mo period, stents were placed in 6.2% of procedures; during the last 6-mo period, stents were placed in 46.3% of procedures, an eightfold increase. During the final 6 mo, an unapproved device or an unapproved indication for an approved device constituted 59.4% of all stent procedures. In addition, use of the non-FDA-approved adjunctive treatment regimen without warfarin increased from 2.9% in the first 6-mo period of observation to 82.7% in the last 6 mo. The use of stents increased strikingly over a 36-mo period, from 6% to 46% of all procedures. The majority of implantations were performed either for an "off-label" unapproved indication or with an unapproved device.

Mechanical pressure and stretch release endothelin-1 from human atherosclerotic coronary arteries in vivo

BACKGROUND

Endothelin-1 (ET-1) is an endothelium-derived vasoactive peptide with mitogenic properties. In vitro, vascular release of ET-1 is increased in response to mechanical stress. The goal of the present study was to examine whether ET-1 is released from human atherosclerotic coronary arteries in vivo in response to mechanical pressure and stretch and to characterize immunoreactivity for ET-1 and its precursor, big ET-1, within the atheromatous plaque.

METHODS AND RESULTS

Circulating ET-1 levels were measured in 20 patients before and after coronary angioplasty for stable angina at three sampling sites: the femoral artery and the coronary artery segments proximal and distal to the lesion dilated. In addition, atheromatous tissue obtained from 20 patients undergoing directional coronary atherectomy for stable angina were analyzed for immunoreactivity for ET-1 and big ET-1. In patients undergoing angioplasty, ET-1 levels in the distal coronary artery increased after balloon dilatation (8.4 +/- 0.9 to 16.4 +/- 2 pg/mL, P < .05); proximal coronary artery and systemic ET-1 levels were unchanged. The degree of mechanical stress applied (product of duration and pressure of balloon inflation) correlated with the change in distal coronary artery ET-1 levels (r = .71, P < .01). Immunoreactivity for big ET-1 and ET-1 was ubiquitous in the extracellular space and the intracellular compartment (macrophages, myointimal cells, myofibroblasts, and endothelial cells) of human coronary atheromatous tissue.

CONCLUSIONS

Big ET-1 and ET-1 immunoreactivity is ubiquitous within the intracellular and extracellular compartments of coronary atherosclerotic tissue. ET-1 is released from these sites in response to mechanical stress. These findings support a role for endothelins in the evolution and progression of coronary atherosclerosis in humans.

Effect of subintimal resection on initial outcome and restenosis for native coronary lesions and saphenous vein graft disease treated by directional coronary atherectomy. A report from the CAVEAT I and II investigators. Coronary Angioplasty Versus Excisional Atherectomy Trial

OBJECTIVES

This study was designed to determine whether the depth of tissue resection affected either immediate outcome or subsequent restenosis in patients treated by directional coronary atherectomy (DCA) in the Coronary Angioplasty Versus Excisional Atherectomy Trial (CAVEAT) I and II studies.

BACKGROUND

The relation between the depth of tissue resection, immediate outcome and subsequent restenosis in lesions treated with DCA has been controversial.

METHODS

In CAVEAT I, 412 patients undergoing DCA had tissue samples available for analysis by the core laboratory, whereas in CAVEAT II, 113 patients had vein graft tissue specimens available.

RESULTS

Subintimal deep arterial wall resection was demonstrated in 169 patients (41%) in CAVEAT I and 40 (35%) in CAVEAT II. The depth of tissue resection did not affect initial procedural outcome in either CAVEAT I or CAVEAT II, nor did it affect subsequent restenosis rates at 6 months in native coronary lesions (CAVEAT I, 50.8% for intimal resection vs. 51.2% for subintimal resection). In patients treated with vein graft disease (CAVEAT II), restenosis rates varied; when resection was limited to the intima, a restenosis rate of 40.4% was documented, whereas in patients with subintimal resection, the restenosis rate was 57.1%. This difference was not statistically significant (p = 0.144).

CONCLUSIONS

This combined randomized series of DCA for treatment of primary native coronary artery and vein graft stenoses with quantitative coronary angiography and core laboratory pathologic assessment resolves the controversy created by previous experimental and clinical data regarding deep vessel wall resection and immediate and longer outcome. Directional atherectomy with deep arterial wall resection as practiced in these studies is safe and does not jeopardize initial success rates. More important, deep wall resection is not associated with significantly increased restenosis rates.

Secular trends in coronary atherosclerosis--analysis in patients with valvular regurgitation

BACKGROUND

Between 1980 and 1989, mortality due to coronary artery disease decreased considerably in the United States, suggesting a possible decrease in the prevalence of coronary atherosclerosis. We examined this possibility in patients with valvular regurgitation who, often in the absence of angina, underwent coronary angiography before valve-replacement surgery.

METHODS

We studied 601 patients with isolated, nonischemic valvular regurgitation who were operated on between 1980 and 1989 and who had undergone preoperative coronary angiography. From the angiograms we determined the prevalence of clinically significant coronary artery disease and of multivessel disease, assessed the mean degree of stenosis, and analyzed the trends in the data over the years of the study.

RESULTS

The prevalence of coronary artery disease (35 percent in 1980-1981, 37 percent in 1982-1983, 34 percent in 1984-1985, 37 percent in 1986-1987, and 35 percent in 1988-1989; P = 0.97) did not change significantly during the study period. We found no significant change in the prevalence of multivessel disease (24 percent in 1980-1981 and 23 percent in 1988-1989, P = 0.99) or in the mean ( +/- SD) degree of stenosis (11 +/- 13 percent in 1980-1981 and 13 +/- 14 percent in 1988-1989, P = 0.07). When these measures of coronary atherosclerosis were adjusted for age and sex, there were still no significant changes over time (P = 0.39 for the prevalence of coronary artery disease, P = 0.81 for that of multivessel disease, and P = 0.57 for the mean degree of stenosis). The patients' mean total cholesterol level decreased from 219 +/- 48 mg per deciliter (5.66 +/- 1.24 mmol per liter) to 206 +/- 44 mg per deciliter (5.33 +/- 1.14 mmol per liter) between 1980 and 1989 (P = 0.04).

CONCLUSIONS

From 1980 to 1989, no significant change was observed in angiographic measures of coronary atherosclerosis in patients with nonischemic valvular regurgitation, in contrast to the marked decrease in mortality due to coronary disease in the general population. These findings suggest that the well-documented reduction in mortality due to coronary disease may not be due to a reduction in the prevalence of coronary atherosclerosis.

Coronary angioplasty and intracoronary thrombolysis are of limited efficacy in resolving early intracoronary stent thrombosis

OBJECTIVES

This study sought to evaluate treatment of early intracoronary stent thrombosis.

BACKGROUND

Although refinements in intracoronary stent implantation technique and pharmacologic treatment have reduced the frequency of early stent thrombosis, stent thrombosis remains a feared complication of this procedure. Optimal treatment for stent thrombosis is still undefined.

METHODS

Twenty-nine patients (44 stents) with early (< or = 30 days) coronary stent thrombosis over a 5-year period at our institution were identified. Treatment and outcome of stent thrombosis were analyzed.

RESULTS

Mean (+/- SD) time from implantation to stent thrombosis was 6.1 +/- 5 days. Twenty-three patients were treated with catheter-based therapies (angioplasty alone in 14, angioplasty and intracoronary urokinase in 7, intracoronary urokinase alone in 2). Flow was restored without residual thrombus in 11 (48%) of the catheter-treated patients (6 of 14 with angioplasty alone, 4 of 7 with angioplasty and urokinase, 1 with urokinase alone). Of the 23 patients, 2 died despite restoration of anterograde flow, and 9 were referred for emergent or urgent bypass surgery because of residual thrombus and refractory angina despite restoration of blood flow. Of the remaining six patients, five were treated medically and one with coronary bypass surgery; three died. Acute myocardial infarction evolved in 26 patients (90%), including 20 (87%) of the 23 catheter-treated patients.

CONCLUSIONS

Stent thrombosis is associated with severe adverse outcomes. Although catheter-based therapies are effective in restoring patency in a majority of patients, patients are referred frequently for coronary bypass surgery because of residual thrombus and refractory angina. These findings suggest that alternative or adjunctive therapies for stent thrombosis are needed.

Impact of stent size and indication for stent placement on immediate outcome

The immediate outcome of 271 procedures involving the intracoronary implantation of 305 stents was determined. Data were analyzed with regard to indication for stenting and stent size. Elective indication was associated with a higher success rate than emergency indication (95.6% vs. 86.6%, P = 0.013) and a lower Q-wave infarction rate (0 vs. 6.4%, P = 0.006). Univariate analysis showed that the odds ratio for procedural success was significantly favored by elective indication (3.37, P = 0.018) but was unrelated to stent size (1.10, P = 0.087). These findings were confirmed on multivariate analysis. The likelihood of Q-wave infarction was lower for elective placement (P = 0.0008) but was not related to size. Requirement for emergency bypass surgery, incidence of subacute closure, and death were not related to indication or to stent size on either univariate or multivariate analysis. Therefore, the immediate outcome of stent placement is related to the indication for stenting, but not to the size of stent implanted. Procedural success is significantly favored by elective indication.

Percutaneous revascularization strategies. Usefulness in ischemic coronary artery disease

Current data support the use of revascularization procedures in many patients with ischemic symptoms or silent myocardial ischemia. Patients with extensive disease may benefit even when ischemia cannot be demonstrated. The development of new devices, particularly coronary stents, has broadened the population of patients who can be treated in the cardiac laboratory. Patients with acute myocardial infarction are best treated with direct angioplasty. If thrombolytic therapy is used, rescue angioplasty should probably be done when lysis is unsuccessful. Angioplasty should be used selectively in patients with successful thrombolysis. Both bypass surgery and angioplasty are reasonable initial strategies for patients with stable angina or significant silent ischemia who require coronary revascularization.

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.

Endothelin in coronary endothelial dysfunction and early atherosclerosis in humans

BACKGROUND

The endothelium modulates vascular tone through release of vasodilating substances, such as endothelium-derived relaxing factors, and vasoconstricting substances, such as endothelin. Endothelin concentrations are elevated in humans with atherosclerosis and in hypercholesterolemic pigs. Furthermore, the endothelium-dependent vasodilator acetylcholine increases endothelin in hypercholesterolemia in association with coronary vasoconstriction. The present study was designed to test the hypotheses that coronary endothelial dysfunction in humans is characterized by enhanced coronary and circulating endothelin and that the vasoconstriction associated with acetylcholine results in further release of coronary endothelin.

METHODS AND RESULTS

Coronary and circulating endothelin concentrations were measured at baseline and during intracoronary acetylcholine administration in 20 patients undergoing diagnostic coronary angiography. Patients were divided into two groups on the basis of their response to intracoronary acetylcholine. Group 1 (n = 7) demonstrated a normal vasodilatory response, but group 2 (n = 13) demonstrated coronary vasoconstriction. Baseline coronary and circulating endothelin concentrations (as determined by coronary sinus and femoral artery measurements, respectively) were higher in patients who responded to acetylcholine with coronary vasoconstriction (group 2) than in group 1 patients (coronary sinus, 15.9 +/- 1.0 pg/mL versus 7.1 +/- 1.0 pg/mL; femoral, 14.1 +/- 0.9 pg/mL versus 6.8 +/- 1.0 pg/mL, respectively; P < .01). In response to intracoronary acetylcholine, a further increase in coronary endothelin was observed only in group 2; this increase correlated with changes in coronary artery diameter.

CONCLUSIONS

This study demonstrates that endothelin immunoreactivity is enhanced in the coronary and systemic circulation in humans with coronary endothelial dysfunction. Moreover, acetylcholine further increased coronary endothelin concentration in patients with coronary endothelial dysfunction and was associated with coronary vasoconstriction. These observations strongly support a role for endothelin as an early participant in and marker for coronary endothelial dysfunction in humans.

Time to reperfusion and other procedural characteristics of emergency coronary artery bypass surgery after unsuccessful coronary angioplasty

A databank search was performed and 148 consecutive patients (mean age 59.5 +/- 10.4 years) were identified who underwent emergency coronary artery bypass surgery at the Mayo Clinic between November 20, 1979, and February 12, 1992, immediately after unsuccessful coronary angioplasty. At the end of the angioplasty procedure, there was no anterograde coronary blood flow in the treated artery in 54%, ongoing chest pain in 78%, and hemodynamic compromise requiring intravenous vasopressor therapy in 25% of patients; 127 patients (86%) had at least 1 of these adverse characteristics. After leaving the catheterization laboratory, the median time to arrival in the operating room was 12 minutes. Median time from arrival in the operating room to initiation of cardiopulmonary bypass was 86 minutes, to administration of cardioplegia was 98 minutes, and to removal of the aortic cross-clamp was 135 minutes. In-hospital mortality was 11%, and 18% developed nonfatal Q-wave myocardial infarction. Thus, significant time is required to achieve surgical reperfusion after unsuccessful coronary angioplasty.

A novel approach to the placement of Palmaz-Schatz biliary stents in saphenous vein grafts

The placement of Palmaz-Schatz biliary stents has become a successful method to treat stenoses in large saphenous vein grafts. Unlike coronary stents, the biliary stents are not routinely delivered with a selective delivery sheath and may be more difficult to deliver and prone to detachment from the balloon and even embolization during delivery. In order to enhance the ability to deliver these stents, a guide-within-a-guide system was developed. A 7F guiding catheter was used as a selective delivery sheath within a standard guiding catheter. Nineteen biliary stents were successfully placed in vein grafts in 15 patients using this system. One procedure was complicated by an embolic event documented angiographically following intragraft delivery of urokinase but prior to stent implantation.

Guidewire transection during rotational coronary atherectomy due to guide catheter dislodgement and wire kinking

Rotational coronary atherectomy is an effective treatment for calcified ostial lesions. We report a case of guidewire transection during rotational atherectomy of a right coronary artery ostial stenosis. Guide catheter dislodgement appeared to have caused prolapse and kinking of the guidewire. Advancement of the burr over the kinked wire resulted in transection. The wire fragment was retrieved successfully using an inflated fixed-wire balloon catheter. This report illustrates the importance of excellent coaxial guide catheter alignment with rotational atherectomy and suggests that operators be vigilant to possible damage to the radiolucent rotational atherectomy guidewire.

Management of balloon rupture during rigid stent deployment

Balloon rupture may occur during stent placement and will only become apparent when the stent has been maneuvered across the target stenosis and deployment is attempted. Withdrawal may be complicated by displacement of the stent off the balloon. We describe two cases in which a power injector was used to momentarily inflate the balloon and partially expand the stent in place. The punctured balloon could then be withdrawn and the stent fully deployed, using a new balloon.

Long-term outcome of women compared with men after successful coronary angioplasty

BACKGROUND

Women who undergo coronary angioplasty have a higher in-hospital mortality than men, although much of this difference can be accounted for by their poorer clinical characteristics at the time of their procedures. However, whether or not there are important long-term differences in outcome between women and men after coronary angioplasty is not clear.

METHODS AND RESULTS

A retrospective analysis was performed of 3027 consecutive patients (824 women and 2203 men) who underwent successful angioplasty and who have been followed continuously for a mean of 5.5 years (range, 0.5 to 14 years). Follow-up is 100% complete. Event-free survival was assessed by the Kaplan-Meier method, and clinical end points were also examined by Cox proportional-hazards models to account for important baseline differences when appropriate. There was a trend toward lower survival among women during follow-up, but this was not significant (P = .06). The relative risk of death among women compared with men after adjustment for baseline differences was 0.94 (CI, 0.76 to 1.15; P = NS). No significant sex differences in occurrence of Q-wave myocardial infarction were observed. Women were less likely to remain free of angina after 10 years (34% versus 37%, respectively; P = .008), but after adjustment for baseline differences, this difference was not significant (relative risk of angina, 1.07; CI, 0.95 to 1.21). Women tended to have less coronary artery bypass surgery performed during follow-up (P = .06); adjusting for baseline differences made this difference more significant (relative risk, 0.79; CI, 0.64 to 0.96; P = .02). Among patients who were not treated in the setting of acute infarction, no sex differences in survival and freedom from myocardial infarction were noted.

CONCLUSIONS

After successful coronary angioplasty, the long-term prognosis for women is excellent and is similar to that observed in men. Risk-adjusted survival did not differ significantly between the sexes, but less frequent use of subsequent surgical revascularization was observed in women.

Characteristics and consequences of myocardial infarction after percutaneous coronary intervention: insights from the Coronary Angioplasty Versus Excisional Atherectomy Trial (CAVEAT)

OBJECTIVES

We examined the results of the Coronary Angioplasty Versus Excisional Atherectomy Trial (CAVEAT) to determine the characteristics and consequences of creatine kinase (CK) and creatine kinase, MB myocardial isoenzyme fraction (CK-MB) elevations after percutaneous coronary intervention.

BACKGROUND

Enzyme elevations after interventional procedures have usually been thought to be without long-term clinical consequences. However, recent preliminary reports have suggested that there are important long-term clinical sequelae in patients with even mild enzyme elevations after coronary procedures.

METHODS

Patients with new native lesions undergoing coronary intervention at 35 clinical sites were randomized to undergo percutaneous coronary angioplasty (n = 500) or directional coronary atherectomy (n = 512). Cardiac enzyme levels were measured 12 and 24 h after the interventional procedure and when clinically indicated for recurrent myocardial ischemia. Enzyme profiles were analyzed using a ratio that compared the peak enzyme level and the local laboratory upper limit of normal. Standard 12-lead electrocardiograms (ECGs) recorded before and after the procedure were interpreted by two independent readers who had no knowledge of the randomization data. Postprocedural myocardial infarction was defined as the appearance of new Q waves on the ECG, CK-MB levels three or more times the upper limit of normal or a total CK concentration two or more times the upper limit of normal when CK-MB levels were unavailable. Regression models were used to evaluate the predictive significance of a postintervention myocardial infarction with respect to clinical outcomes at 30 days and 1 year.

RESULTS

There were 78 myocardial infarctions in the atherectomy group and 34 in the angioplasty group (15.2% vs. 6.8%, p = 0.001). Patients with a myocardial infarction more often had a repeat intervention or emergency coronary artery bypass surgery. Hospital length of stay was increased among patients with an infarction, as were mean hospital costs ($17,340.65 vs. $11,308.47, p = 0.0003). Postprocedural myocardial infarction was highly predictive of mortality, bypass surgery or repeat intervention within 30 days (p < 0.0001).

CONCLUSIONS

Myocardial infarction occurred commonly after coronary intervention in CAVEAT and was associated with a worse clinical outcome. Although the incidence of myocardial infarction was higher with atherectomy than with angioplasty, the baseline characteristics and consequences of the infarctions were similar between the treatments with regard to 30-day outcome. Myocardial enzyme elevations after an otherwise successful interventional procedure may identify a population at risk for a future cardiac event.