Results of direct percutaneous transluminal coronary angioplasty in octogenarians

Effect of Age on Procedural Success, Complications, and Clinical Outcome From a Large Angioplasty Registry

BACKGROUND

Increasing age appears to be a risk factor for adverse outcome in patients undergoing percutaneous coronary intervention (PCI). The goal of this study was to compare procedural success, complications, and 12 months major adverse cardiac events (MACE) based on age using a large angioplasty registry.

METHODS

This registry included 10,412 patients with at least 12-month follow-up from April 1993 to April 2011. Patients were divided into 3 age groups: group 1 age < 60 (n = 6195), group 2 age 60-75 (n = 3724) and group 3 elderly age ≥ 75 (n = 493).

RESULTS

Procedural success rate was not significantly different across the 3 age groups. (96.9% in group 1, 97.1% in group 2, and 96.1% in elderly group, P = 0.759). Procedural complications occurred in 179 (2.9%) of group 1, 98 (2.6%) of group 2 and 15 (3.0%) of elderly group (P = 0.678). In-hospital complications increased with increasing age (311 [5.0%] in group 1, 235 [6.3%] in group 2, and 46 [9.3%] in elderly group; P < 0.001). Twelve-month MACE also increased with increasing age (235 [4.1%] in group 1, 169 [4.9%] in group 2 and 26 [5.7%] in elderly group; P = 0.021). Multivariate analysis showed that age was not a predictor for unsuccessful PCI, procedural complications, or 12-month MACE. However, increasing age was independent predictors of in-hospital complications and death.

CONCLUSION

Despite increased in-hospital complications with increasing age, procedural success, and complications were not higher in elderly. Our data suggest that PCI should not be denied in elderly if indicated with procedural safety similar to other age groups.

Angiographic no-reflow and six-month mortality in elderly (>/= 75 years old) Asian patients undergoing primary percutaneous coronary intervention: A single center experience from 1998 to 2007

BACKGROUND

We sought to report the incidence of angiographic no-reflow and clinical outcomes of elderly patients who have undergone primary percutaneous coronary intervention at a tertiary institution in Singapore over a period of 10 years.

METHODS

A total of 141 patients (60% male) aged 75 or above underwent primary PCI between 1998 and 2007. Their average age was 80+/-5 years. Cardiogenic shock complicating STEMI on presentation accounted for 15% of the patients.

RESULTS

At baseline, 103 (73%) patients have impaired TIMI flow grade (TIMI 0-2), and 38 (27%) have normal flow (TIMI 3). At the end of the procedure, 44 (31.2%) patients had no-reflow phenomenon (TIMI 0-2), whereas 97 (68.8%) achieved normal antegrade flow. Post-procedure corrected TIMI frame count was analyzable in 66% (n=93) of the patients. Post-procedure corrected TIMI frame count was>28 in 37.6% (n=35) of patients. In-hospital, 30-day and six-month mortalities were 20.6, 25.5% and 27.7%, respectively. Multivariable analysis showed that age 80 or above, low systolic blood pressure and final TIMI 0-2 flow independently predicted six-month mortality.

CONCLUSIONS

We found that one-third of the treated patients developed no-reflow phenomenon. Six-month mortality was 27.7%, most were cardiac deaths that occurred during index hospitalization.

Genetic influence on electrocardiogram time intervals and heart rate in aging mice

Understanding the genetic influence on ECG time intervals and heart rate (HR) is important for identifying the genes underlying susceptibility to cardiac arrhythmias. The objective of this study was to determine the genetic influence on ECG parameters and their age-related changes in mice. ECGs were recorded in lead I on 8 males and 8 females from each of 28 inbred strains at the ages of 6, 12, and 18 mo. Significant interstrain differences in the P-R interval, QRS complex duration, and HR were found. Age-related changes in the P-R interval, QRS complex duration, and HR differed among strains. The P-R interval increased with age in 129S1/SvlmJ females. The QRS complex duration decreased with age in C57BR/J males and DBA2/J females but increased in NON/ShiLtJ females. HR decreased in C57L/J females and SM/J and P/J males but increased in BALB/cByJ males. Differences between males and females were found for HR in SJL/J mice and in the P-R interval in 129S1/SvlmJ mice. Broad-sense heritability estimates of ECG time intervals and HR ranged from 0.31 for the QRS complex duration to 0.52 for the P-R interval. Heritability estimates decreased with age for the P-R interval. Our study revealed that genetic factors play a significant role on cardiac conduction activity and age-related changes in ECG time intervals and HR.

Clinical characteristics and early outcomes of very elderly patients in the reperfusion era

BACKGROUND

Not much data is available regarding "real-world" clinical experience of very elderly patients with acute myocardial infarction (AMI) in the reperfusion era.

METHODS

We reviewed 483 patients (26%) between the ages of 75 and 85 from the 1855 patients with AMI. We analyzed 264 patients treated with reperfusion therapy (55%) and 219 patients treated with conservative therapy (45%) on their clinical characteristics and early outcomes.

RESULTS

Patients treated with reperfusion therapy were slightly younger (79.0 vs. 80.0 years, P=0.01), presented earlier (205 vs. 400 minutes, P<0.01) and had higher peak creatine kinase values (2634 vs. 1407 IU/l, P<0.01) than those treated with conservative therapy. Other clinical profiles including sex, prior myocardial infarction, hypertension, diabetes, and infarct location were similar to each other. There was a 92% success for reperfusion therapy. The incidence of recurrent ischemia, cardiac rupture, and cerebral hemorrhage was not significantly different between the two groups. In-hospital mortality in this study was 20.5%. In-hospital mortality was not significantly different between the two groups (19% vs. 23%, P=0.25). The multivariate analysis showed that age, infarct location, and Killip class were correlated to in-hospital mortality. The leading cause of in-hospital death was pump failure.

CONCLUSIONS

Older age and late presentation were correlated to conservative therapy in very elderly patients with AMI. Early outcomes were similar between the two treatment groups. In-hospital mortality seemed to be associated with impaired myocardial reserve.

Hospital disposition and long-term follow-up of patients aged >/=80 years undergoing coronary artery revascularization

Coronary artery revascularization by either percutaneous coronary intervention or coronary artery bypass graft surgery in patients >/=80 years of age can be accomplished with acceptable in-hospital and 2-year clinical outcomes. However, up to 20% of patients have a prolonged recovery and are unable to immediately return home. It is important that this information become part of the discussion with patients and their families so realistic expectations can be developed.

The dilemma of success: percutaneous coronary interventions in patients > or = 75 years of age-successful but associated with higher vascular complications and cardiac mortality

Elderly patients are increasingly referred to percutaneous coronary interventions (PCIs). Recent reports suggest complications rates are declining in the elderly. We sought to determine whether procedural and in-hospital outcomes are different in patients aged > or = 75 years undergoing nonemergent PCI as compared to patients age < 75 years. The outcome of 266 consecutive patients age > or = 75 years undergoing nonemergent PCI was compared to that of 1,681 consecutive patients age < 75 years. Compared with younger patients, greater proportions of elderly patients were women and had a history of hypertension, peripheral vascular disease, and cerebral vascular events. Elderly patients had more extensive coronary involvement. Procedural success was similar in both groups (94%). The in-hospital cardiac death rate was significantly higher in the elderly patients (2.3% vs. 0.7%; P = 0.03). Aged patients also had a significantly higher incidence of vascular and bleeding complications. Blood transfusion was required more often in the elderly group (4.5% vs. 2.6%; P = 0.07). The hospitalization length was significantly higher in the elderly group (4.1 +/- 6.0 vs. 2.5 +/- 4.3 day; P = 0.0004). By multivariate logistic regression (adjusted for baseline clinical and angiographic variables), age > or = 75 years was found to be an independent predictor of in-hospital cardiac death (odds ratio = 3.9; 95% CI = 1.3-11.5; P = 0.015). Although PCI is technically successful in patients aged > or = 75 years; it is associated with more acute cardiac and vascular complications and higher in-hospital cardiac mortality.

Comparison of primary angioplasty and conservative treatment on short- and long-term outcome in octogenarian or older patients with acute myocardial infarction

It has long been established that advanced age is not only associated with greater myocardial infarction frequency but also greater mortality and morbidity. The treatment of acute myocardial infarction (AMI) in 80 year old patients remains problematic with conflicting results; in these patients, the risks of conservative treatment are high and the risks and benefits of thrombolytic therapy are still controversial. The purpose of this study was to evaluate whether primary angioplasty can offer an important alternative method to improve short- and long-term outcomes in octogenarian or older patients who experience AMI. Between May 1986 and March 2000, 171 consecutive 80 year old patients hospitalized for AMI were not randomized to be registered and divided into a medical therapy group (group 1: an historical control group, n=11) and a primary angioplasty group (group 2, n=60). In-hospital mortality was markedly increased with advanced Killip scores (Killip 3 or 4) in both groups. Twenty-four hours after admission, group 1 patients had a significantly higher incidence of progression to higher Killip scores than did group 2 patients (P=0.006). The 30-day overall mortality of group 2 patients was significantly lower than in group 1 patients (30.0% vs 54.1%, P=0.003). Patients without cardiogenic shock treated by primary angioplasty had a significantly lower incidence of overall mortality at 30 days than patients without cardiogenic shock treated conservatively [3.1% vs 24.3%, P=0.016 (Killip 1 and 2); 18.2% vs 52.6%, P=0.044 (Killip 3)]. However, the mortality rate of cardiogenic shock was extremely high and did not differ significantly between groups I and 2 (86.1% vs 88.2%, P=0.99). The 3-year cumulative survival rate was significantly higher in group 2 than in group 1 patients (P=0.0009). In conclusion, primary angioplasty is feasible and effective, and can improve short-and long-term mortalities in octogenarian or older patients with AMI but without cardiogenic shock.

Comparison of results of coronary angioplasty for acute myocardial infarction in patients > or =75 years of age versus patients <75 years of age

We reviewed 1,063 consecutive patients treated with direct coronary angioplasty for acute myocardial infarction (AMI): 261 were > or =75 and 802 were <75 years of age. Compared with the younger group, the older group had a higher percentage of women (48% vs 22%, p <0.0001), multivessel coronary disease (50% vs 39%, p <0.01), overall in-hospital mortality (8.4% vs 3.7%, p <0.01), cardiac mortality rate (6.1% vs 3.1%, p <0.05), and noncardiac mortality rate (2.3% vs 0.6%, p <0.05). Successful reperfusion was achieved in both groups at a similarly high rate (93% and 95%, p = NS). Hospital mortality was similar whether reperfusion was successful or failed. Successful compared with unsuccessful angioplasty decreased mortality rates in the older (6.6% vs 33%, p <0.0001) and younger (3.0% vs 18%, p <0.0001) groups. When reperfusion was successful, the cardiac mortality rate in older patients was not significantly higher than in younger patients: 4.1% vs 2.4%, p = NS.

Antiarrhythmic agents in facilitating electrical cardioversion of atrial fibrillation and promoting maintenance of sinus rhythm

Atrial fibrillation (AF) is a prevalent arrhythmia associated with significant morbidity and mortality. Electrical cardioversion of AF is a potentially definitive treatment, but as little as 67% of patients may be successfully cardioverted and, after normal sinus rhythm (NSR) is achieved, AF often recurs. Class IA, IC, and III antiarrhytmic agents are used for both facilitation of electrical cardioversion and subsequent maintenance of NSR. The mechanisms of these agents may be related to suppressing automaticity, prolonging the wavelength of reentrant wavelets, and preventing electrical remodeling. The possibility of proarrhythmia and other adverse effects complicates use of these drugs, and no large trials have been completed to elucidate definite indications. Several factors may predict failure with electrical cardioversion alone (duration of AF, atrial size, age, underlying disease, and factors that affect transthoracic impedance), calling for empiric pharmacotherapy to facilitate cardioversion. For this purpose, class IA agents hold some promise, evidence for class IC agents is conflicting, and class III agents are the most effective. Adverse effects are rare given the short course before cardioversion, but ibutilide, the most efficacious in this regard, may be proarrhythmic after only a single dose. In promoting maintenance of sinus rhythm, antiarrhythmics across the different classes have similar efficacies: NSR may be maintained in approximately 40-65% of patients compared to approximately 30-35% with placebo at 1 year. Amiodarone is distinct in its success, with approximately 60-80% of patients remaining in NSR. For all of these agents, long-term therapy may lead to proarrhythmia or other substantial adverse effects. Finally, a serial antiarrhythmic strategy may be effective, with maintenance of NSR and minimal adverse effects ultimately achieved by trial and error.

Methods for determining the refractory period and excitable gap during persistent atrial fibrillation in the goat

BACKGROUND

Recently, the temporal excitable gap during atrial fibrillation (AF) has been identified as a vulnerable parameter for cardioversion of AF. In this study, we evaluated 5 methods to measure the refractory period (RP(AF)) and the excitable period (EP(AF)) during persistent AF.

METHODS AND RESULTS

In 11 goats instrumented with 83 epicardial atrial electrodes, persistent AF (43+/-34 days) was induced with a median AF cycle length (CL) of 98+/-14 ms. To measure RP(AF), premature stimuli were applied to the center of the electrode array on the right or left atrium. The RP(AF) measured by mapping of premature stimuli was 70+/-12 ms ("gold standard"). The RP(AF) determined during entrainment of AF was 77+/-17 ms (R(2)=0.88, P<0.01). Statistical analysis of the effects of synchronized stimuli (each coupling interval x100) on the AFCL histogram yielded an RP(AF) of 70+/-13 ms (R(2)=0.94, P<0.01). A further simplification was to apply slow fixed-rate pacing (1 Hz) during AF. For each stimulus (n=250 to 500), the paced AFCL was plotted against its coupling interval, and capture was determined by statistical shortening of the AFCL (RP(AF) 71+/-17 ms, R(2)=0.84, P<0.01). The 5th percentile of the AFCL histogram as an index of RP(AF) was 77+/-12 ms (R(2)=0.90, P<0.01).

CONCLUSIONS

During persistent AF with an AFCL of 98+/-14 ms, the RP(AF) determined by mapping of synchronized premature stimuli (gold standard) was 70+/-12 ms, with an excitable period of 28+/-8 ms. Although the indirect methods to measure RP(AF) all correlated well with the gold standard, slow fixed-rate pacing seems to be the most attractive technique because of the ease of acquiring the data and the clear graphic result.

Assessment of global atrial fibrillation organization to optimize timing of atrial defibrillation

BACKGROUND

We hypothesized that frequency domain analysis of a wide bipolar interatrial electrogram describes the global organization of atrial fibrillation (AF) and should vary over time. By timing shocks to periods of high organization of AF, cardioversion efficacy should improve.

METHODS AND RESULTS

A total of 15 dogs (weight, 28.2+/-3.4 kg) were rapidly paced for 48 to 72 hours to induce AF. Coil electrodes with a surface area of 1.80 cm(2) were then placed in the left and right atria to form a wide bipole. Wide bipolar electrograms were digitally filtered, and a fast Fourier transform was performed over a sliding 2-s window every 0.5 s. The organization index (OI) was calculated as the ratio of the area of the dominant peak and its harmonics to the total area of the magnitude spectrum. The atrial defibrillation threshold (ADFT(50)) was determined using a 3-ms/3-ms biphasic shock and an up-down-up protocol. Additional shocks with higher and lower energies were delivered in a random sequence to develop a distribution curve. The OI varied over time, with a mean of 0.42+/-0.03, a maximum of 0.65+/-0.07, and a minimum of 0.20+/-0.06. The OI changed rapidly, with durations of high organization (OI>0.5) ranging from 1 to 5 s. The ADFT(50) for QRS complex-synchronized shocks was 183+/-56 V, versus 142+/-49 V for shocks synchronized to an OI>0.5 (P<0.001). The distribution curve shifted leftward when shocks were synchronized to an OI>0.5.

CONCLUSIONS

AF signals show a high degree of variability. Shock efficacy is increased when shocks are delivered during periods of high AF organization as determined by the OI method.

Results of Stent Supported Percutaneous Transluminal Coronary Angioplasty in Octogenarians With Coronary Artery Disease

Between January 1995 and July 1998, percutaneous transluminal coronary angioplasty was performed on 27 lesions in 24 octogenarians. Half of the patients were African American. Women comprised 67% of the study group. Patients with unstable angina and myocardial infarction constituted 54% of the cohort. Two-thirds of the patients (83%) had single vessel disease with predominant class A and B lesion complexity of the angioplasty site. Acute success rate was 92%. Stents were successfully placed in 11 subjects (46%). None had acute myocardial infarction, emergency coronary artery bypass surgery, or stroke as a complication of the procedure. One patient presenting with acute myocardial infarction complicated by cardiogenic shock, died. Significant bleeding complications requiring blood transfusions occurred in 17% of patients. Of the patients, 23 (96%) were discharged in a clinically stable condition. Follow up during a two year period was completed in 21 patients (88%). One patient died of cancer. Four subjects (19%) underwent repeat percutaneous transluminal coronary angioplasty. One other patient had recurrent chest pain requiring multiple hospitalizations. The remaining 16 patients (76%) remained free of recurrence of angina. We concluded that percutaneous transluminal coronary angioplasty with stent placement can be performed in octogenarians with a high rate of clinical and angiographic success with an acceptable range of morbidity and mortality, and favorable long term (two year) outcome. (c) 2000 by CVRR, Inc.

Primary angioplasty for acute myocardial infarction in the elderly

Elderly patients with acute myocardial infarction present a formidable therapeutic challenge. Although there appears to be a survival benefit from thrombolytic therapy for the eligible elderly patient, persistent concerns regarding the risk of intracranial hemorrhage impedes utilization in this age group. Primary or direct angioplasty of the infarct artery has been proven to be an effective modality for reperfusion. Randomized comparisons suggest an advantage over thrombolysis in terms of achieving superior patency and mitigating recurrent ischemic events. Primary angioplasty expands the reperfusion population by including many patients ineligible for thrombolysis and is more effective for treating patients at high risk, such as those with cardiogenic shock. Acute angiography accumulates important prognostic and decision-facilitating information. The benefits of primary angioplasty are more impressive for the aging patient. The survival gain and reduction in intracranial hemorrhage may combine to magnify the advantages of performing angioplasty on patients in this group. Emerging evidence concerning the aging population validates continued examination of this invasive reperfusion approach.

Short-term effects of rapid pacing on mRNA level of voltage-dependent K(+) channels in rat atrium: electrical remodeling in paroxysmal atrial tachycardia

BACKGROUND

Atrial fibrillation causes electrophysiological changes of the atrium, thereby facilitating its maintenance. Although the expression of ion channels is modulated in chronic atrial fibrillation, it is yet unknown whether paroxysmal atrial fibrillation can also lead to electrical remodeling by affecting gene expression.

METHODS AND RESULTS

To examine the short-term effects of rapid pacing on the mRNA level of voltage-dependent K(+) channels, high-rate atrial pacing was performed in Sprague-Dawley rat hearts. Total RNA was prepared from the atrial appendages from 0 to 8 hours after the onset of pacing, and mRNA levels of Kv1.2, Kv1. 4, Kv1.5, Kv2.1, Kv4.2, Kv4.3, erg, KvLQT1, and minK were determined by RNase protection assay. Among these 9 genes, the mRNA level of the Kv1.5 channel immediately and transiently increased, with bimodal peaks at 0.5 and 2 hours after the onset of pacing. Conversely, the pacing gradually and progressively decreased the mRNA levels of the Kv4.2 and Kv4.3 channels. The increase of Kv1.5 and the decrease of Kv4.2 and Kv4.3 mRNA levels were both rate dependent. In correspondence with the changes in the mRNA level, Kv1. 5 channel protein transiently increased in the membrane fraction of the atrium during a 2- to 8-hour pacing period. Electrophysiological findings that the shortening of the action potential produced by 4-hour pacing was almost abolished by a low concentration of 4-aminopyridine implied that the increased Kv1.5 protein was functioning.

CONCLUSIONS

Even short-term high-rate atrial excitation could differentially alter the mRNA levels of Kv1.5, Kv4.2, and Kv4.3 in a rate-dependent manner. In particular, increased Kv1.5 gene expression, having a transient nature, implied the possible biochemical electrical remodeling unique to paroxysmal tachycardia.

Systematic primary angioplasty in octogenarian and older patients

BACKGROUND

There are conflicting data about the efficacy of aggressive treatment and early intervention among high-risk patients with acute myocardial infarction (AMI), such as elderly patients. This study sought to determine the short- and long-term outcome of octogenarian and older patients after primary percutaneous transluminal coronary angioplasty (PTCA).

METHODS

In our tertiary referral center a program of primary PTCA was begun in 1995, and the systematic care for AMI included primary PTCA in all patients with AMI, with no age restriction. Over a period of 3 years, 55 octogenarian or older patients underwent primary PTCA.

RESULTS

Between January 1995 and July 1998, 719 patients with AMI underwent primary PTCA. Of these, 55 patients were octogenarians or older (mean age, 84 +/- 3 years). Primary PTCA failure occurred in 3 (5%) patients. An optimal acute angiographic result was achieved in 51 (93%) patients. Stenting of the infarct vessel was accomplished in 33 (60%) patients. The 30-day mortality rate was 16%. The mortality rate was 4% in patients without cardiogenic shock on presentation and 70% in patients with cardiogenic shock. The recurrent ischemia rate was 13% and resulted in nonfatal reinfarction in 2 patients and repeat PTCA in 5 patients. As determined by multivariate analysis, an optimal acute angiographic result and cardiogenic shock were significantly related to mortality. The 1-year survival rate was 77%.

CONCLUSIONS

The results of this study suggest that the benefits of primary PTCA apply to the very elderly and support an early aggressive strategy for this high-risk patient subset.

Angioplasty but not thrombolysis improves short-term mortality of acute myocardial infarction. A multicenter survey in Yamagata, Japan

There are few district-based surveys to investigate the actual effects of thrombolytic therapy and percutaneous transluminal coronary angioplasty (PTCA) on short-term mortality in patients with acute myocardial infarction (AMI) in Japan. The study population comprised 974 patients (319 women and 655 men, aged 69 +/- 12 years) admitted with confirmed AMI to 41 hospitals in Yamagata Prefecture from January 1, 1994 to December 31, 1996. Thrombolysis and PTCA were performed in 262 (27%) and 428 (44%) patients, respectively, and 161 patients died within 28 days after the onset of AMI (short-term mortality 16.5%). Thirteen variables, including risk factors and clinical manifestations, were examined by bivariate and multiple logistic regression analyses to identify the predictors of short-term mortality. Multiple logistic regression analysis, incorporating variables with a p value < 0.05 in a bivariate analysis, demonstrated that advanced age, history of myocardial infarction and Killip class III or IV independently correlated with increased short-term mortality and treatment with PTCA independently correlated with decreased short-term mortality (odds ratio 0.21, 95% confidence interval [CI] 0.11-0.39). Thrombolytic therapy was not an independent predictor of short-term mortality (odds ratio 0.67, 95% CI 0.37-1.20). Treatment with PTCA but not thrombolysis significantly improved the short-term mortality in patients with AMI in our area-based study.

Initial results and long-term clinical and angiographic implications of coronary stenting in elderly patients

Results of 378 consecutive elderly patients (> or = 65 years) undergoing coronary stenting were compared with those of 601 younger patients. Although the restenosis rate was similar in the 2 groups, age > or = 65 years was an independent predictor of in-hospital mortality (relative risk 5.4, 95% confidence interval 1.2 to 20.1) and follow-up mortality (relative risk 2.8, 95% confidence interval 1.3 to 6.1).

[Arterial myocardial revascularization in the 9th decade of life. Personal results and review of the literature]

The rate of the population being 80 years of age and even older, has an increasing tendency in the Federal Republic of Germany. In 1996, a total of 87,372 patients received surgery supported by the heart-lung-machine, 2,383 patients out of these (2.7%) were 80 years of age and older. In view of the limited life expectance, the arterial revascularization in this age category is faced with controverse discussions. We analysed our patients in relation to this aspect. Between January 1, 1995 and June 30, 1997, 4,338 patients underwent surgery supported by the heart-lung-machine. Hundred and fifty-five out of these (3.6%) were in the 9th decade of life. Seventy-seven patients out of the 155 (49.7%, 34 women, 43 men, 80 to 88 years old, mean: 82 years of age) underwent an isolated myocardial revascularization. We performed 55 (71%) elective, 16 (21%) urgent and 6 (8%) emergency surgeries. Twelve patients (15.6%) solely received venous bypasses (Group I), 65 (84.4%) additionally also received unilateral bypasses of the internal mammaria artery (IMA) (Group II). Three patients died at our facility (3.9%), 3 further patients died during the follow-up treatment in outlying hospitals, the in-patient mortality rate in Group I therefore presented a rate of 8.3%, in Group II 7.7% and in total, a rate of 7.8%. In 1996, the in-patient mortality rate could be reduced to 3.6%. The follow-up observation time ranged between 7 and 138 weeks (median 44 weeks). The survival rate for patients with an IMA-bypass after 1 year was 86.3%, after 2 years 77%, and for the entire collective 85.3% and 75%. Whereas 96% of the patients could pre-operatively be related to Class III or IV of the NYHA-classification, 55 of the 63 survivors (87%) belonged to Class I (6%) or II (81%). Two Group I patients (22.2%), 3 Group II patients (5.6%) and 7.9% of the total collective complained about repeated angina symptoms. The myocardial revascularization with the internal mammaria artery performed on patients in the 9th decade of life, achieves an acceptable morbidity and mortality compared to solely venous coronary bypasses. The more prolonged follow-up observation period will clarify, whether the arterial myocardial revascularization also proves to be the superior method in this age category.

Therapy for acute myocardial infarction in older persons

OBJECTIVE

To review the early management of acute myocardial infarction (AMI) in older adults.

METHODS

Recently published studies relevant to the early management of AMI were systematically reviewed. When possible, the impact of older age on complication rates and clinical outcomes was evaluated.

RESULTS

In general, AMI therapies that are effective in younger patients are also effective in older patients. Conversely, older age is associated with an increased risk of complications from therapy, implying that careful patient selection is required to optimize outcomes while minimizing risks. The principal limitation of currently available data is that relatively few patients older than the age of 80 have been enrolled in prospective randomized clinical trials.

CONCLUSIONS

Thrombolysis and primary angioplasty are effective in establishing reperfusion and improving clinical outcomes in older patients with AMI. In the absence of contraindications, aspirin and beta blockers should be considered standard therapy in AMI patients of all ages, whereas heparin, nitrates, and angiotensin converting enzyme inhibitors are indicated in selected subgroups. At the present time, calcium channel blockers, magnesium, and antiarrhythmic agents are not recommended for routine use in the AMI setting, and the role of glycoprotein IIb/IIIa inhibitors, low molecular weight heparin, and other newer agents await the results of ongoing clinical trials.

Purkinje-muscle reentry as a mechanism of polymorphic ventricular arrhythmias in a 3-dimensional model of the ventricles

Multiple electrode mapping of the ventricles during complex tachyarrhythmias has revealed focal subendocardial activation whose mechanism remains unexplained. We hypothesized that reentry involving the Purkinje-muscle junctions (PMJs) may be a mechanism for such focal excitations. We have constructed an anatomically appropriate computerized 3-dimensional model of the mammalian ventricles that includes the Purkinje conduction system and 214 PMJs distributed throughout the endocardium. Isochronal maps during normal excitation, as well as during right or left bundle branch block, resembled experimental measurements and compared well with isochronal maps of propagation in the human heart. Activity observed at both sides of a PMJ in the model showed that propagation from Purkinje fibers to muscle was slower than in the opposite direction. Under these realistic and normal conditions, the evolution of reentrant activity involving muscle and the Purkinje network was simulated. The reentry pattern was independent of the initiation site. It evolved with drifting epicardial breakthroughs and transformed on the endocardium from focal activity to figure-of-8 reentry. In addition, the ECG amplitude undulated during the evolution, and decrease in the cycle period, apparent wavelength, and propagation velocity were observed. Finally, the reentry was terminated if the Purkinje system was disconnected from the muscle before it reached a relative steady state. The simulation results suggest the following: (1) Epicardial breakthroughs and endocardial focal activity may originate at the PMJs. (2) The ECG amplitude may decrease as the reentry stabilizes and the excitation wavelength decreases. (3) The Purkinje system may have a double role in the evolution of reentry: first, it is essential to the reentry at the initial stage; second, it may lead to the establishment of intramyocardial reentry, at which time the Purkinje system becomes irrelevant.

Coronary artery stenting for suboptimal PTCA results in acute myocardial infarction in patients treated with Abciximab: early and six-month outcome

Emergent percutaneous transluminal coronary angioplasty (PTCA) is an effective treatment for acute myocardial infarction. However, occasionally results of angioplasty are suboptimal due to coronary dissection or elastic recoil, leading to a high chance of recurrent ischemia. Coronary stents are occasionally employed in such settings, but a high incidence of stent thrombosis was noted by early investigators when stents were placed into areas of active thrombus formation. Since coronary thrombosis and stent thrombosis are both initiated by platelets, the potent antiplatelet agent abciximab might be useful in preventing stent thrombosis. Little information is available concerning early outcome or 6-month clinical event rate when coronary artery stents are placed for suboptimal angioplasty results for acute myocardial infarction in patients given abciximab. We deployed 75 stents as part of angioplasty for acute myocardial infarction in 40 patients given abciximab. All patients had suboptimal angioplasty results leading to stent deployment. Each obtained normal flow angiographically and no stent thrombosis or acute closure was observed. Early mortality occurred in 1 patient. All patients were followed at least 6 months, and no patient died after hospital discharge. Three patients experienced recurrent ischemic events within the first 6 months. Two of these events were due to infarct vessel restenosis. We conclude the combined use of coronary artery stents and abciximab for suboptimal PTCA results during acute myocardial infarction is associated with a low incidence of culprit vessel recurrent ischemic events within 6 months of intervention.