Comparative outcomes of percutaneous coronary interventions in diabetics vs non-diabetics with prior coronary artery bypass grafting

AIMS

To determine the influence of diabetes on outcome after percutaneous coronary intervention in patients with prior coronary artery bypass grafting.

METHODS AND RESULTS

Patients with prior coronary artery bypass grafting undergoing percutaneous coronary intervention from 1 January 1996, to 31 August 2000, were divided into two groups based on whether or not they had diabetes, excluding patients with acute infarction or shock. Cox proportional hazards models were utilized to estimate the association between diabetes and adverse events. One thousand one hundred and fifty-three post-coronary artery bypass grafting percutaneous coronary intervention patients were identified (326 diabetics and 827 non-diabetics). Diabetics were younger, more likely to have hypertension, heart failure, and lower ejection fraction. Procedural characteristics and angiographic and procedural success rates were similar. Diabetes was associated with increased mortality (hazard ratio 1.58, 95% confidence intervals 1.10-2.27). Diabetes did not have a significant effect on mortality in patients treated for single-territory coronary disease (hazard ratio 1.44, 95% confidence intervals 0.69-3.02), but did in patients with multi-territory disease (hazard ratio 1.79, 95% confidence intervals 1.16-2.76). However, in diabetics with multi-territory disease who were completely revascularized with percutaneous coronary intervention, mortality was comparable to non-diabetics (hazard ratio 1.32, 95% confidence intervals 0.57-3.03).

CONCLUSION

Among percutaneous coronary intervention patients with prior coronary artery bypass grafting, diabetes portends an adverse prognosis.

Gallbladder disorders and type 2 diabetes mellitus--a clinic-based study

AIMS OF THE STUDY

To study the prevalence of gallbladder disorders in type 2 diabetic patients and their correlation with patient factors like age, sex, weight, duration of diabetes and autonomic neuropathy.

METHODOLOGY

Fifty type 2 diabetic patients and 30 healthy controls underwent realtime ultrasonography to study the prevalence of gallbladder disorders. The fasting gallbladder volume and contraction 60 minutes after a fatty meal of the diabetic subjects were compared with 30 age and sex matched healthy volunteers. The age, sex, weight, duration of diabetes, autonomic neuropathy, control of diabetes were correlated to the prevalence of gallbladder disorders in diabetic patients.

RESULTS

32% of the diabetic patients had ultrasonographic evidence of gallstones, as compared to 6.7% in healthy subjects. 73.7% of the diabetic patients with gallbladder disorders were females. Mean fasting gallbladder volume was significantly increased in diabetic patients (26.2 cm3) as compared to non-diabetic healthy subjects (15.8 cm3). Further mean fasting gallbladder volume of diabetic patients with gallbladder disorder (28.1 cm3) was found to be significantly larger than that of those patients without gallbladder disorder (24.6 cm3). Mean percentage of contractions of gallbladder 60 min after fatty meal was reduced in diabetic patients (53.1%) and it was observed to be further reduced in the patients with gallbladder disorder (41.8%). Mean fasting gallbladder volume was larger in diabetic subjects with autonomic neuropathy, than those without. However, difference in mean percentage contraction of gallbladder 60 min after fatty meal was not statistically significant. Mean duration of diabetes was significantly longer in diabetic patients with gallbladder disorder.

CONCLUSIONS

We conclude that type 2 diabetic patients have increased prevalence of gallbladder disorder which can only partially be explained by autonomic neuropathy leading, to increased fasting volume. Factors like decreased cholecystokinin or decreased sensitivity of the smooth muscle of gallbladder to normal level of cholecystokinin need to be studied.

Early coronary angiography improves long-term survival in unstable angina

BACKGROUND

The role of early coronary angiography in the evaluation of patients with unstable angina has been controversial. This study was designed to determine the effect of early coronary angiography on long-term survival in patients with unstable angina.

METHODS

We reviewed the Olmsted County Acute Chest Pain Database, a population-based epidemiologic registry that includes all patients residing within Olmsted County who were seen for emergency department evaluation of acute chest pain from 1985 to 1992. Patients with symptoms consistent with myocardial ischemia qualifying as unstable angina were classified as undergoing early (</=7 days of index presentation) angiography or not.

RESULTS

A total of 2264 patients with symptoms consistent with unstable angina were identified with a mean duration of follow-up of 6 years; 892 underwent early angiography. Early angiography patients were younger; less likely to have heart failure; more likely to be male, hypercholesterolemic, and smokers; had prior coronary revascularization; and had a myocardial infarction at the index presentation. After baseline differences were controlled, early angiography was associated with a reduction in all-cause long-term mortality (relative risk 0.63, 95% CI 0.53-0.74). Patients at intermediate or high risk for death or myocardial infarction at presentation were most likely to benefit from early angiography.

CONCLUSION

Early angiography in the evaluation of patients with unstable angina was associated with a reduction in all-cause mortality, particularly in intermediate- and high-risk patients, in this retrospective population-based study.

Ankle brachial index as a predictor of generalized atherosclerosis

OBJECTIVE

To assess ankle brachial index (ABI) as a screening method to target subclinical atherosclerosis in middle aged individuals.

MATERIAL AND METHODS

Total 160 patients over the age of 40 years were included in the study for a period of 16 months. Their ABI was determined either by colour Doppler method (30 patients) and/or sphygmomanometry (all 160 patients). A value of < 0.9 was taken as cutoff point for significant stenosis.

RESULTS

Total 69 patients out of total of 160 had significantly low ABI value (43.12%) which shows that there is a very high incidence of low ABI in the community. Overall > 50% of the patients were largely asymptomatic and had presence of two or more risk factors. ABI < 0.9 was a good screening test to detect such individuals at an earlier stage (sub-clinical).

CONCLUSION

A significantly low (< 0.9) ABI value can detect subclinical atherosclerotic vascular involvement and predict future occurrence of preventable major vascular event.

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 risk stratification correlates with the angiographic extent of coronary artery disease in unstable angina

OBJECTIVES

We sought to determine whether clinical risk stratification correlates with the angiographic extent of coronary artery disease (CAD) in patient with unstable angina.

BACKGROUND

The Agency for Health Care Policy and Research (AHCPR) guidelines stratify patients with unstable angina according to short-term risk of myocardial infarction or death. Whether these guidelines are useful in predicting the extent of CAD is unknown.

METHODS

All residents of Olmsted County, Minnesota, undergoing emergency department evaluation from January 1, 1985 through December 31, 1992 for unstable angina without a history of prior coronary artery bypass grafting, and who underwent early angiography (within seven days of presentation) were classified into low, intermediate and high risk subgroups based on AHCPR criteria.

RESULTS

Seven hundred ninety-five patients underwent early angiography: 159 high risk, 572 intermediate risk and 64 low risk patients. Logistic regression analysis demonstrated that low risk patients had a greater likelihood of normal or mild CAD relative to intermediate risk (odds ratio [OR], 4.67; 95% confidence interval [CI], 2.70-8.06; p < 0.001) and high risk (OR, 11.1; 95% CI, 5.71-22.2; p < 0.001). Significant 1-, 2-, 3-vessel coronary disease or left main coronary disease was more likely in high relative to low risk (OR, 8.09; 95% CI, 4.22-15.5; p < 0.001), intermediate relative to low risk (OR, 4.11; 95% CI, 2.34-7.22; p < 0.001), and high relative to intermediate risk (OR, 1.97; 95% CI, 1.31-2.96; p = 0.0012).

CONCLUSIONS

Among patients with unstable angina undergoing early coronary angiography, risk stratification according to the AHCPR guidelines correlates with the angiographic extent of CAD.

Evaluation of long-term survival after successful percutaneous coronary intervention among patients with chronic renal failure

We studied the long-term outcomes after percutaneous coronary intervention in dialysis patients and in patients with chronic renal failure (CRF) (serum creatinine > or = 3.0 mg/dl). All-cause mortality at 1 year was 2.9% for the control group, 16.2% for the group with CRF, and 14.1% for dialysis patients. Cardiac mortality at 1 year was 1.9% for ther control group, 15.2% for the group with CRF, and 10.0% for dialysis patients.

Altered effects of potassium channel modulation in the coronary circulation in experimental hypercholesterolemia

OBJECTIVE

To evaluate the role of potassium channels in the regulation of coronary hemodynamics in experimental hypercholesterolemia.

BACKGROUND

Potassium (K(+)) channels play an important role in coronary vasoregulation. It has previously been demonstrated that experimental hypercholesterolemia is associated with altered coronary vasomotion; however, the role of K(+) channels in modulating coronary blood flow in this pathophysiologic state has not been evaluated.

METHODS AND RESULTS

Pinacidil (group 1, n=5) at 2 microg/kg per min, glibenclamide (group 2, n=5), or N-monomethyl-L-arginine (LNMMA) (group 3, n=4) at 50 microg/kg per min were infused into the left anterior descending artery of pigs prior to and following 10 weeks of 2% cholesterol diet. After 10 weeks of cholesterol feeding, intracoronary pinacidil resulted in a significant increase in coronary blood flow (CBF) and coronary artery diameter (CAD) compared to the normolipidemic state (111+/-10 versus 59+/-12%, and 6+/-1.1 versus 2.7+/-1.0%, respectively, P<0.05 for both comparisons), whereas intracoronary glibenclamide resulted in a significant decrease in CBF and CAD compared to the normolipidemic state (-17+/-5 versus 5+/-6%, and -0.8+/-1.4 versus 3.6+/-1.6%, respectively, P<0.05 for both comparisons). The effect of intracoronary LNMMA on CBF and CAD was significantly attenuated after 10 weeks of cholesterol feeding as compared to the normolipidemic state (-47+/-5.4 versus -0.8+/-6.8%, and -19.4+/-5.7 versus -2.3+/-3.3%, respectively, P<0.05 for both comparisons). Furthermore, pretreatment with intracoronary LNMMA did not alter the CBF response to pinacidil in normal pigs (group 4, n=4) (57.4+/-19 versus 59+/-12%, P=NS).

CONCLUSIONS

The current study demonstrates an enhanced effect of coronary K(+) channel modulation and confirms the attenuated basal NO activity previously reported in experimental hypercholesterolemia. Acute withdrawal of basal NO activity alone, however, does not explain the enhanced effect of coronary K(+) channel modulation. These findings underscore the importance of the K(+) channel pathway in the regulation of coronary vasomotor tone in pathophysiologic states.

Increased coronary effects of stimulation of endothelin-B receptor in experimental hypercholesterolemia

BACKGROUND

Vasoconstriction in response to endothelin-1 has been shown to be primarily related to its effects on the endothelin-A receptor. Experimental hypercholesterolemia is associated with an increase in coronary vasoconstrictor response to endothelin-1 in vivo, although the relative contributions of subtypes of endothelin receptor in this model remain unknown.

OBJECTIVE

To test the hypothesis that there is an increase in coronary vasoconstriction in response to stimulation of endothelin-B receptor in hypercholesterolemia, which might be related to attenuation of activity of endothelin-derived relaxing factor.

METHODS

We infused 5 ng/kg/min sarafotoxin, a specific endothelin-B receptor agonist, or 50 micrograms/kg/min NG-monomethyl-L-arginine (L-NMMA), a competitive inhibitor of nitric oxide synthase, into the left anterior descending coronary arteries of pigs before and after feeding them a cholesterol-rich diet for 10 weeks.

RESULTS

There was a significant increase in serum level of cholesterol. After 10 weeks, infusion of sarafotoxin resulted in an accentuated decrease in coronary blood flow (CBF) compared with baseline (decreases by 60 +/- 7 versus 34 +/- 6%, P < 0.05). There was no significant difference between the effects on diameter of coronary arteries for the two time periods. The effect of L-NMMA on CBF was attenuated after 10 weeks (by 5 +/- 10.1 versus 45.6 +/- 4.7%, P < 0.05). Endothelin-receptor status of epicardial coronary arteries remained unchanged. Sarafotoxin and L-NMMA were co-infused at the above-mentioned doses into normolipidemic animals; the decrease in CBF in response to this co-infusion was comparable to the decrease observed with sarafotoxin alone in hypercholesterolemic animals (decreases of 67 +/- 5 versus 60 +/- 7, NS).

CONCLUSIONS

The present results demonstrate that selective stimulation of the endothelin-B receptor increases coronary vasoconstriction in experimental hypercholesterolemia, primarily at the level of the microvasculature. These findings may be related to the attenuation of activity of endothelin-derived relaxing factor in this model, and support the hypothesis that endothelin-B receptor plays a role in the regulation of coronary vascular tone in pathophysiologic states.

Effect of abciximab on late adverse events in patients with diabetes mellitus undergoing stent implantation

Percutaneous coronary intervention (PCI) in patients with diabetes mellitus (DM) is associated with higher rates of adverse cardiac events. Recent data suggest that adverse events are reduced in DM after PCI using stents with abciximab. We performed a retrospective analysis of a prospective PCI registry for all patients with DM who underwent stent placement at the Mayo Clinic from 1995 to 1997 (n = 570), and divided them into 2 groups based on whether abciximab was administered. Characterization and comparison of the clinical and angiographic variables, procedural outcomes, and short- and long-term event rates between groups was performed. The baseline clinical characteristics of the groups were similar, but patients treated with abciximab were more likely to be men with a lower left ventricular ejection fraction. Patients treated with abciximab had more multivessel intervention, saphenous vein graft intervention, and thrombus before intervention. The 30-day mortality rate (0.6% vs 3.0%, p = 0.03) and repeat PCI (0% vs 1.1%, p = 0.03) was lower in patients treated with abciximab. The 30-day rates of bypass surgery, myocardial infarction (MI), and a composite of death, MI, and revascularization were similar. The 1-year event rates did not differ significantly between patients taking and not taking abciximab for the end points of death (8.9% vs 8.8%, p = 0.97), MI (13.3% vs 11.4%, p = 0.57), bypass surgery (10.3% vs 6.2%, p = 0.20), repeat PCI (14.7% vs 15.9%, p = 0.76), and a composite of death, MI, and revascularization (30.4% vs 26.7%, p = 0.43). After adjusting for baseline variables, abciximab did not influence the occurrence of late adverse events.

Comparison of percutaneous interventions for unstable angina pectoris in patients with and without previous coronary artery bypass grafting

An increasing number of patients who have undergone previous coronary artery bypass grafting (CABG) are referred for percutaneous coronary revascularization. We identified patients who underwent percutaneous intervention for unstable angina from 1990 to 1998 at our institution and assigned them into 2 groups based on whether or not they had undergone previous CABG. There were 1,431 patients with and 4,629 patients without previous CABG. Previous CABG patients were older, had more atherosclerotic risk factors, more heart failure, lower ejection fraction, more multivessel disease, more multilesion treatment, more complex lesions, and less complete revascularization. Adjusting for baseline differences, previous CABG was associated with worse long-term mortality (RR 1.47, 95% confidence intervals [CI] 1.22 to 1.77, p < 0.001) and death, myocardial infarction, and/or revascularization (RR 1.16, 95% CI 1.04 to 1.30, p = 0.01); treatment of native lesions in patients with previous CABG versus treatment of vein graft lesions was associated with a reduction in this composite end point (RR 0.75, 95% CI 0.65 to 0.87, p < 0.001). Post-CABG patients treated between 1995 and 1998 had lower long-term mortality (RR 0.76, 95% CI 0.59 to 0.99, p = 0.04) and death, myocardial infarction, and/or revascularization (RR 0.76, 95% CI 0.66 to 0.88, p < 0.001) compared with those treated between 1990 and 1994. Thus, in patients with unstable angina referred for percutaneous revascularization, previous CABG is associated with reduced event-free survival, although the outcome of post-CABG patients treated from 1995 to 1998 is superior to that observed in patients treated from 1990 to 1994. In patients who underwent previous CABG, treatment of native lesions affords better long-term outcome than vein graft intervention.

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.

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.

Percutaneous coronary interventions in patients with prior coronary artery bypass surgery: changes in patient characteristics and outcome during two decades

PURPOSE

Patients who develop recurrent myocardial ischemia after coronary artery bypass graft (CABG) surgery are often referred for percutaneous coronary interventions. The objective of this study was to evaluate the changing demographic and clinical characteristics, and procedural and long-term outcomes, in patients with prior CABG referred for percutaneous coronary interventions during a 20-year period.

METHODS

We prospectively collected data on patients who underwent coronary interventional procedures following CABG surgery. We compared angiographic and procedural success, and long-term event-free survival, among patients who had procedures from 1979 to 1989 (n = 393), from 1990 to 1994 (n = 811), and from 1995 to 1998 (n = 937).

RESULTS

Patients in the 1995 to 1998 cohort were older, had a lower mean left ventricular ejection fraction, and were more likely to have diabetes, hypertension, and hyperlipidemia, but less likely to smoke. They were more likely to have treatment of complex lesions, including vein graft lesions, and had more prior CABG surgeries. More patients received intracoronary stents in 1995 to 1998. Both angiographic success rates (78% from 1979 to 1989, 88% from 1990 to 1994, and 91% from 1995 to 1998, P < 0.0001) and procedural success rates (78%, 86%, and 91%, P < 0.0001) improved with time. Long-term mortality was greater in the pre-1990 group (relative risk = 1.8, 95% confidence interval: 1.3 to 2.4) and 1990 to 1994 group (relative risk = 1.7, 95% confidence interval: 1.3 to 2.2) compared with the 1995 to 1998 group, as were the likelihoods of repeat revascularization and recurrent severe angina.

CONCLUSION

Although the demographic and clinical characteristics of patients who underwent percutaneous intervention following CABG surgery indicate that they are at increasingly greater risk of adverse cardiac events, success rates and long-term survival have improved with time. The rates of recurrent severe angina as well as of subsequent revascularization have also decreased, probably as a result of improvements in technique and greater use of stents and adjunctive medications.

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.

Clopidogrel versus ticlopidine after intracoronary stent placement

OBJECTIVES

The study compared the safety and efficacy of ticlopidine with clopidogrel in patients receiving coronary stents.

BACKGROUND

Stent thrombosis is reduced when ticlopidine is administered with aspirin. Clopidogrel is similar to ticlopidine in chemical structure and function but has fewer side effects; few data are available about its use in stent patients.

METHODS

We compared 30-day event rates in 500 consecutive coronary stent patients treated with aspirin and clopidogrel (300 mg loading dose immediately prior to stent placement, and 75 mg/day for 14 days) to 827 consecutive stent patients treated with aspirin and ticlopidine (500 mg loading dose and 250 mg twice daily for 14 days).

RESULTS

Patients treated with clopidogrel had more adverse clinical characteristics including older age, more severe angina, and more frequent infarction within the prior 24 h. Nonetheless, mortality was 0.4% in clopidogrel patients versus 1.1% in ticlopidine patients; nonfatal myocardial infarction occurred in 0% versus 0.5%, stent thrombosis in 0.2% versus 0.7%, bypass surgery or repeat angioplasty in 0.4% versus 0.5%, and any event occurred in 0.8% versus 1.6% of patients, respectively (p = NS). Based on the observed 30-day event rate of 1.6% with ticlopidine, the statistical power of the study was 43% to detect an even rate of 0.5% with clopidogrel, and 75% to detect an event rate with of 4% with clopidogrel, with a p value of 0.05.

CONCLUSIONS

These data indicate that clopidogrel can be safely substituted for ticlopidine in patients receiving coronary stents.

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.

Management of tuberculosis in Wales: 1986-92

OBJECTIVES

To describe the epidemiology of childhood tuberculosis in Wales and to assess the standard of management of patients with tuberculosis.

DESIGN

Retrospective study of data retrieved from case notes and review of radiographs of all identified patients.

SUBJECTS

Forty eight cases of tuberculosis and 10 of tuberculosis chemoprophylaxis in children under 15 years of age, in Wales, between January 1986 and December 1992.

MAIN OUTCOME MEASURES

Management of childhood tuberculosis in Wales compared with the published recommendations of the Joint Tuberculosis Committee of the British Thoracic Society.

RESULTS

Documentation was poor in most of the 48 cases of tuberculosis and only 31 (65%) were formally notified. One third of patients were asymptomatic and were detected by contact tracing; only eight (17%) were culture positive. Only 20% of patients from ethnic minorities had previously been immunised with BCG. Management and chemotherapy varied widely. Few patients were managed jointly by paediatricians and chest doctors. Only 10% completed treatment with a recommended chemotherapy regimen. In 37% of patients treatment was inadequate, and in the remainder either the choice of drugs or the duration of treatment was inappropriate. No patient died, nor had any relapsed by June 1995.

CONCLUSIONS

Very few cases of childhood tuberculosis were managed according to the recommendations of the British Thoracic Society.

New insight into coronary endothelial dysfunction: role of endothelin

The coronary endothelium plays a central role in the modulation of coronary vascular tone via the production and release of vasoactive mediators. A number of cardiovascular disease states are associated with coronary endothelial dysfunction, which results in an imbalance between vasoactive substances. Endothelin is a potent vasoconstrictor produced by the coronary endothelium and has been implicated in the pathogenesis of coronary endothelial dysfunction. This review examines the relationship between endothelin and coronary endothelial dysfunction as it occurs in a number of cardiovascular disease states and explores potential therapeutic options.

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.