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.

Effect of time since onset of risk factors on the occurrence of ischemic stroke

OBJECTIVE

To determine the effect of time since onset of risk factors on the modeling of risk factors for ischemic stroke.

METHODS

The resources of the Rochester Epidemiology Project allowed identification of the 1,397 incident cases of ischemic stroke and age- and sex-matched control subjects from the population for 1970 through 1989. These cases and controls permitted the development of a multiple conditional logistic regression model to estimate the odds ratios of ischemic stroke for various risk factors. The time since onset variables for each risk factor were then added to the model to determine which were significant and to assess their impact on variables in the model.

RESULTS

The time since onset variables for congestive heart failure and TIA were the only variables of this type included in the resultant model. Each showed the highest risk for stroke soon after the onset of the risk factor. In addition, the influence of congestive heart failure was higher at younger ages. Hypertension (with or without left ventricular hypertrophy) increases the risk for stroke but has a diminishing influence with increasing age. In addition, persons with left ventricular hypertrophy are at a higher risk than those with hypertension alone, although this difference also decreases with age. The time since onset variables pertaining to systolic hypertension at 140 to 159 mm Hg, 160 to 179 mm Hg, and > or =180 mm Hg were not significant in any analysis.

CONCLUSIONS

TIA and congestive heart failure were the only risk factors for stroke for which time since onset was significant in the model for predicting ischemic stroke.

T-cell immunity in acute coronary syndromes

Acute coronary syndromes (ACS) are complications of atherosclerotic vascular disease that are triggered by the sudden rupture of an atheroma. Atherosclerotic plaque stability is determined by multiple factors, of which immune and inflammatory pathways are critical. Unstable plaque is characterized by an infiltrate of T cells and macrophages, thereby resembling a delayed hypersensitivity reaction. On activation, T cells secrete cytokines that regulate the activity of macrophages, or the T cells may differentiate into effector cells with tissue-damaging potential. Constitutive stimulation of T cells and macrophages in ACS is not limited to the vascular lesion but also involves peripheral immune cells, suggesting fundamental abnormalities in homeostatic mechanisms that control the assembly, turnover, and diversity of the immune system as a whole. This review gives particular attention to the emergence of a specialized T-cell subset, natural killer T cells, in patients with ACS. Natural killer T cells have proinflammatory properties and the capability of directly contributing to vascular injury.

Molecular fingerprint of interferon-gamma signaling in unstable angina

BACKGROUND

Activation of circulating monocytes in patients with acute coronary syndromes may reflect exposure to bacterial products or stimulation by cytokines such as IFN-gamma. IFN-gamma induces phosphorylation and nuclear translocation of transcription factor STAT-1, which initiates a specific program of gene induction. To explore whether monocyte activation is IFN-gamma driven, patients with unstable (UA) or stable angina (SA) were compared for nuclear translocation of STAT-1 complexes and upregulation of IFN-gamma-inducible genes CD64 and IP-10.

METHODS AND RESULTS

Peripheral blood mononuclear cells were stained for expression of CD64 on CD14(+) monocytes and analyzed by PCR for transcription of IP-10. Expression of CD64 was significantly increased in patients with UA. Monocytes from UA patients remained responsive to IFN-gamma in vitro, with accelerated transcriptional competency of CD64. IP-10-specific sequences were spontaneously detectable in 82% of the UA patients and 15% of SA patients (P<0.001). Most importantly, STAT-1 complexes were found in nuclear extracts prepared from freshly isolated monocytes of patients with UA, which provides compelling evidence for IFN-gamma signaling in vivo.

CONCLUSIONS

Monocytes from UA patients exhibit a molecular fingerprint of recent IFN-gamma triggering, such as nuclear translocation of STAT-1 complexes and upregulation of IFN-gamma-inducible genes CD64 and IP-10, which suggests that monocytes are activated, at least in part, by IFN-gamma. IFN-gamma may derive from stimulated T lymphocytes, which implicates specific immune responses in the pathogenesis of acute coronary syndromes.

Time trends in the prevalence of atherosclerosis: a population-based autopsy study

PURPOSE

Mortality from coronary heart disease is declining but little is known about trends in the prevalence of atherosclerosis. Autopsy rates in Olmsted County, Minnesota, are higher than the national average, offering an opportunity to address this matter. In this study, we determined the prevalence of anatomic coronary disease among autopsied Olmsted County residents and examined the generalizability of these findings.

SUBJECTS AND METHODS

Reports of the 2,562 autopsies performed between 1979 and 1994 on Olmsted County residents > or =20 years of age were reviewed for the presence of coronary disease.

RESULTS

Among autopsied decedents less than 60 years old at death and among coroner's cases, the prevalence of anatomic coronary disease declined with time (P for trend = 0.05); no trend was detected among older persons or noncoroner's cases. By logistic regression analysis, the crude odds ratio ([OR] per 5 years) for the association between time and anatomic coronary disease was 0.94 (95% confidence interval [CI]: 0.86 to 1.03; P = 0.18]. Age, sex, and antemortem diagnosis of heart disease were also strongly related to the presence of disease. After adjustment for sex and antemortem diagnosis of heart disease, the prevalence of anatomic coronary disease decreased more in younger people than in older people (age 40 years: OR 0.43 [95% CI: 0.24 to 0.80]; age 60 years: OR 0.62 [95% CI: 0.45 to 0.87]; age 80 years: OR 0.89 [95% CI: 0.64 to 1.23]).

CONCLUSION

The prevalence of anatomic coronary disease at autopsy decreased between 1979 and 1994, particularly among younger people, supporting the notion that the burden of coronary disease has shifted toward the elderly. These results suggest that the decreased incidence of coronary artery disease has contributed to the recent decrease in coronary mortality, particularly among younger people.

Monoclonal T-cell proliferation and plaque instability in acute coronary syndromes

BACKGROUND

Unstable angina (UA) is associated with systemic inflammation and with expansion of interferon-gamma-producing T lymphocytes. The cause of T-cell activation and the precise role of activated T cells in plaque instability are not understood.

METHODS AND RESULTS

Peripheral blood T cells from 34 patients with stable angina and 34 patients with UA were compared for the distribution of functional T-cell subsets by flow cytometric analysis. Clonality within the T-cell compartment was identified by T-cell receptor spectrotyping and subsequent sequencing. Tissue-infiltrating T cells were examined in extracts from coronary arteries containing stable or unstable plaque. The subset of CD4(+)CD28(null) T cells was expanded in patients with UA and infrequent in patients with stable angina (median frequencies: 10.8% versus 1.5%, P<0.001). CD4(+)CD28(null) T cells included a large monoclonal population, with 59 clonotypes isolated from 20 UA patients. T-cell clonotypes from different UA patients used antigen receptors with similar sequences. T-cell receptor sequences derived from monoclonal T-cell populations were detected in the culprit but not in the nonculprit lesion of a patient with fatal myocardial infarction.

CONCLUSIONS

UA is associated with the emergence of monoclonal T-cell populations, analogous to monoclonal gammopathy of unknown significance. Shared T-cell receptor sequences in clonotypes of different patients implicate chronic stimulation by a common antigen, for example, persistent infection. The unstable plaque but not the stable plaque is invaded by clonally expanded T cells, suggesting a direct involvement of these lymphocytes in plaque disruption.

The effect of previous coronary-artery bypass surgery on the prognosis of patients with diabetes who have acute myocardial infarction. Bypass Angioplasty Revascularization Investigation Investigators

BACKGROUND

Acute myocardial infarction in patients with diabetes is associated with high mortality. We studied whether previous revascularization by coronary-artery bypass grafting (CABG), as compared with percutaneous transluminal coronary angioplasty (PTCA), influences the prognosis in such patients.

METHODS

We classified all patients eligible for the Bypass Angioplasty Revascularization Investigation who underwent coronary revascularization within three months after entry into the study according to whether they had diabetes and whether they had undergone CABG, either initially or after PTCA. The protective effect of CABG with regard to mortality in the presence and in the absence of subsequent spontaneous Q-wave myocardial infarction was estimated with the use of Cox regression models.

RESULTS

Among the 641 patients with diabetes and the 2962 without diabetes, the cumulative five-year rates of death were 20 percent and 8 percent, respectively (P<0.001), and the five-year rates of spontaneous Q-wave myocardial infarction were 8 percent and 4 percent (P<0.001). CABG greatly reduced the risk of death after spontaneous Q-wave myocardial infarction in the patients with diabetes (relative risk, 0.09; 95 percent confidence interval, 0.03 to 0.29). Among patients with diabetes who had undergone CABG but did not have spontaneous Q-wave myocardial infarctions, the corresponding relative risk of death was 0.65 (95 percent confidence interval, 0.45 to 0.94). Among the patients without diabetes, no protective effect of CABG was evident.

CONCLUSIONS

Among patients with diabetes, previous coronary bypass surgery, as compared with coronary angioplasty, has a highly favorable influence on prognosis after acute myocardial infarction and a smaller beneficial effect among patients who do not have infarction. These findings should influence the type of coronary revascularization procedure selected for patients with diabetes who have multivessel coronary artery disease.

Sudden death in mitral regurgitation due to flail leaflet

OBJECTIVES

We sought to assess the incidence and determinants of sudden death (SUD) in mitral regurgitation due to flail leaflet (MR-FL).

BACKGROUND

Sudden death is a catastrophic complication of MR-FL. Its incidence and predictability are undefined.

METHODS

The occurrence of SUD was analyzed in 348 patients (age 67 +/- 12 years) with MR-FL diagnosed echocardiographically from 1980 through 1994.

RESULTS

During a mean follow-up of 48 +/- 41 months, 99 deaths occurred under medical treatment. Sudden death occurred in 25 patients, three of whom were resuscitated. The sudden death rates at five and 10 years were 8.6 +/- 2% and 18.8 +/- 4%, respectively, and the linearized rate was 1.8% per year. By multivariate analysis, the independent baseline predictors of SUD were New York Heart Association (NYHA) functional class (p = 0.006), ejection fraction (p = 0.0001) and atrial fibrillation (p = 0.059). The yearly linearized rate of sudden death was 1% in patients in functional class I, 3.1% in class II and 7.8% in classes III and IV. However, of 25 patients who had SUD, at baseline, 10 (40%) were in functional class I, 9 (36%) were in class II and only 6 (24%) in class III or IV. In five patients (20%), no evidence of risk factors developed until SUD. In patients with an ejection fraction > or =60% and sinus rhythm, the linearized rate of SUD was not different in functional classes I and II (0.8% per year). Surgical correction of MR (n = 186) was independently associated with a reduced incidence of SUD (adjusted hazard ratio [95% confidence interval] 0.29 [0.11 to 0.72], p = 0.007).

CONCLUSIONS

Sudden death is relatively common in patients with MR-FL who are conservatively managed. Patients with severe symptoms, atrial fibrillation and reduced systolic function are at higher risk, but notable rates of SUD have been observed without these risk factors. Correction of MR appears to be associated with a reduced incidence of SUD, warranting early consideration of surgical repair.

Perturbation of the T-cell repertoire in patients with unstable angina

BACKGROUND

Monocytes are constitutively activated in unstable angina (UA), resulting in the production of IL-6 and the upregulation of acute phase proteins. Underlying mechanisms are not understood. To explore whether the production of the potent monocyte activator IFN-gamma is altered in UA, we compared cytokine production by T lymphocytes in patients with UA (Braunwald's class IIIB) and with stable angina (SA).

METHODS AND RESULTS

Peripheral blood lymphocytes were collected at the time of hospitalization and after 2 and 12 weeks. Cytokine-producing CD4(+) and CD8(+) T cells were quantified by 3-color flow cytometry after stimulation with phorbol myristate acetate and ionomycin. UA was associated with an increased number of CD4(+) and CD8(+) T cells producing IFN-gamma, whereas patients with SA had higher frequencies of IL-2(+) and IL-4(+) CD4(+) T cells. Expansion of the IFN-gamma( +) T-cell population in UA persisted for at least 3 months. Increased production of IFN-gamma in UA could be attributed to the expansion of an unusual subset of T cells, CD4(+)CD28(null) T cells.

CONCLUSIONS

Patients with UA are characterized by a perturbation of the functional T-cell repertoire with a bias toward IFN-gamma production, suggesting that monocyte activation and acute phase responses are consequences of T-cell activation. IFN-gamma is produced by CD4(+)CD28(null) T cells, which are expanded in UA and distinctly low in SA and controls. The emergence of CD4(+)CD28(null) T cells may result from persistent antigenic stimulation.

Trends in coronary revascularization 1989 to 1997: the Bypass Angioplasty Revascularization Investigation (BARI) survey of procedures

Use of catheter-based and surgical coronary revascularization has steadily increased in North America. Introduction of catheter-based "new devices," including intracoronary stents, has expanded the range of patients who can be treated with percutaneous approaches. We sought to address trends in the practice of catheter-based and surgical coronary revascularization during 1989 to 1997. The 17 North American institutions participating in the NHLBI Bypass Angioplasty Revascularization Investigation (BARI) periodically completed a 5-working day survey of all surgical and catheter-based coronary revascularizations. Data collected included patient demographics, vessel disease, prior interventions, and use of new devices or minimally invasive surgical techniques. The proportion of all procedures that were catheter based (vs surgical) increased from 52.1% in 1989/1990 to 62.0% in 1997 (p <0.001). Among surgically treated patients, prevalence of prior bypass surgery decreased from 13.4% in 1989/1990 to 7.5% in 1997 (p <0.001). In 1997, 3% of surgical procedures used minimal incisions or were performed without cardiopulmonary bypass. Among patients undergoing catheter-based intervention, prevalence of left main disease increased from 2.2% to 5.7% (p <0.001), myocardial infarction within 24 hours increased from 2.4% to 9.7% (p <0.001), and prior bypass surgery increased from 16.2% to 20.8% (p = 0.056). Use of new devices increased from 11.6% of catheter-based procedures in 1990 to 67.0% in 1997 (p <0.001). Compared with the early 1990s, catheter-based revascularization is currently more commonly used for patients with acute myocardial infarction, prior bypass surgery, or severe left main narrowing. These trends are likely due to the proliferation of new devices, especially intracoronary stents, since the mid 1990s.

Trends in heart disease deaths in Olmsted County, Minnesota, 1979-1994

BACKGROUND

Although age-adjusted heart disease mortality has declined since the 1960s, this decline may not have applied equally to all subgroups.

OBJECTIVE

To examine recent trends in heart disease mortality, specifically in women and in the elderly.

METHODS

Age- and sex-specific heart disease mortality (International Classification of Diseases, Ninth Edition, Clinical Modification [ICD-9-CM] codes 390-398, 402, 404-429) in Olmsted County, Minnesota, between 1979 and 1994 were studied.

RESULTS

The total number of heart disease deaths was 3095; 1578 (51%) occurred in women and 1984 (64%) in persons aged 75 years or older. Most heart disease deaths (77%) were coronary disease deaths (ICD-9-CM codes 410-414). Age-adjusted heart disease mortality rates declined from 123 per 100,000 (95% confidence interval [CI], 102-144/100,000) in 1979 to 81 per 100,000 (95% CI, 67-95/100,000) in 1994. Poisson regression analyses indicated that the trends differed according to sex and age. For women, the relative risk (RR) of heart disease death in 1994 compared with 1979 was 0.69 vs 0.53 for men (P = .06). This equates to a decline in heart disease mortality of 2.5% per year in women or 32% over the period and 4.2% per year in men or 47% over the period. The decline was less pronounced as age increased (P < .001). For 60-year-old women, the RR for 1994 compared with 1979 was 0.59, whereas for 80-year-old women, the RR for 1994 compared with 1979 was 0.76. For men, the RR for 1994 compared with 1979 was 0.60 for 80-year-old men vs 0.46 for 60-year-old men.

CONCLUSIONS

Between 1979 and 1994, in Olmsted County, the decline in heart disease mortality was of lesser magnitude in women and in the elderly, emphasizing the importance of age- and sex-specific trends to characterize time patterns in heart disease deaths to target preventive measures.

Is a strategy of intended incomplete percutaneous transluminal coronary angioplasty revascularization acceptable in nondiabetic patients who are candidates for coronary artery bypass graft surgery? The Bypass Angioplasty Revascularization Investigation (BARI)

OBJECTIVES

Our objective was to determine whether a strategy of intended incomplete percutaneous transluminal coronary angioplasty revascularization (IR) compromises long-term patient outcome.

BACKGROUND

Complete angioplasty revascularization (CR) is often not planned nor attempted in patients with multivessel coronary disease, and the extent to which this influences outcome is unclear.

METHODS

Before randomization, in the Bypass Angioplasty Revascularization Investigation, all angiograms were assessed for intended CR or IR via angioplasty. Outcomes were compared among patients with IR intended if assigned to angioplasty, randomized to coronary artery bypass graft surgery (CABG) versus angioplasty; and within angioplasty patients only, among patients with IR versus CR intended.

RESULTS

At 5 years, there was a trend for higher overall (88.6% vs. 84.0%) and cardiac survival (94.5% vs. 92.1%) in CABG versus angioplasty patients with IR intended. The excess mortality in angioplasty patients occurred solely in diabetic subjects; overall and cardiac survival were similar among nondiabetic CABG and angioplasty patients. Freedom from myocardial infarction (MI) at 5 years was higher in nondiabetic CABG versus angioplasty patients (92.4% vs. 85.2%, p = 0.02), vet was similar to the rate observed (85%) in nondiabetic CABG and angioplasty patients with CR intended. Five-year rates of death, cardiac death, repeat revascularization and angina were similar in all angioplasty patients with IR versus CR intended. However, a trend for greater freedom from subsequent CABG was seen in CR patients (70.3% vs. 64.0%, p = 0.08).

CONCLUSIONS

Intended incomplete angioplasty revascularization in nondiabetic patients with multivessel disease who are candidates for both angioplasty and CABG does not compromise long-term survival; however, subsequent need for CABG may be increased with this strategy. Whether the risk of long-term MI is also increased remains uncertain.

Coronary revascularization in diabetic patients: a comparison of the randomized and observational components of the Aypass Angioplasty Revascularization Investigation (BARI)

BACKGROUND

Patients with treated diabetes in the randomized-trial segment of the Bypass Angioplasty Revascularization Investigation (BARI) who were randomized to initial revascularization with PTCA had significantly worse 5-year survival than patients assigned to CABG. This treatment difference was not seen among diabetic patients eligible for BARI who opted to select their mode of revascularization. We hypothesized that differences in patient characteristics, assessed and unmeasured, together with the treatment selection in the registry, at least partially account for this discrepancy.

METHODS AND RESULTS

Among diabetics taking insulin or oral hypoglycemic drugs at entry, angiographic and clinical presentations were comparable between randomized and registry patients. However, more registry patients were white, and registry diabetics tended to be more educated and more physically active and to report better quality of life. Procedural characteristics and in-hospital complications were comparable. The 5-year all-cause mortality rate was 34.5% in randomized diabetic patients assigned to PTCA versus 19.4% in CABG patients (P=0.0024; relative risk [RR]=1.87); corresponding cardiac mortality rates were 23.4% and 8.2%, respectively (P=0.0002; RR=3.10). The CABG benefit was more apparent among patients requiring insulin. In the registry, all-cause mortality was 14.4% for PTCA versus 14.9% for CABG (P=0.86, RR=1.10), with corresponding cardiac mortality rates of 7.5% and 6. 0%, respectively (P=0.73; RR=1.07). These RRs in the registry increased to 1.29 and 1.41, respectively, after adjustment for all known differences between treatment groups.

CONCLUSIONS

BARI registry results are not inconsistent with the finding in the randomized trial that initial CABG is associated with better long-term survival than PTCA in treated diabetic patients with multivessel coronary disease suitable for either surgical or catheter-based revascularization.

Effect of age in the Bypass Angioplasty Revascularization Investigation (BARI) randomized trial

BACKGROUND

The influence of age on the relative success of either percutaneous transluminal coronary angioplasty (PTCA) or coronary artery bypass grafting (CABG) in patients requiring myocardial revascularization continues to be controversial.

METHODS

In the Bypass Angioplasty Revascularization Investigation (BARI) trial, 1,829 patients with symptomatic multivessel coronary artery disease requiring revascularization were randomly assigned to undergo either CABG or PTCA.

RESULTS

Seven hundred nine patients (39%) were 65 to 80 years old at baseline; the other 1,120 were younger than 65 years. The in-hospital 30-day mortality rate for PTCA and CABG in the younger patients was 0.7% and 1.1%, respectively, and that for patients 65 years or older was 1.7% and 1.7%, respectively. In older compared with younger patients, stroke was more common after CABG (1.7% versus 0.2%, p = 0.015) and heart failure or pulmonary edema was more common after PTCA (4.0 versus 1.3%, p = 0.011). In both age groups, CABG resulted in greater relief of angina and fewer repeat procedures. The 5-year survival rate in patients younger than 65 years was 91.5% for CABG and 89.5% for PTCA. In patients 65 years or older, the 5-year survival rate was 85.7% for CABG and 81.4% for PTCA. Cardiac mortality at 5 years was greater in patients assigned to the PTCA group than in those assigned to the CABG group. However, no significant treatment differences were noted in cardiac mortality when only nondiabetic patients were examined.

CONCLUSIONS

Within the context of the Bypass Angioplasty Revascularization Investigation trial, older patients with multivessel coronary disease do well with either PTCA or CABG. Compared with younger patients, older patients had less recurrent angina and were less likely to undergo repeat procedures, particularly among those assigned to undergo CABG. Cardiac mortality was greater in patients 65 years or older assigned to undergo PTCA; however, this difference was not noted when treated diabetic patients were excluded from analysis.

Impact of preoperative symptoms on survival after surgical correction of organic mitral regurgitation: rationale for optimizing surgical indications

BACKGROUND

Surgical correction of mitral regurgitation in patients with no or mild symptoms remains controversial, particularly because the impact of preoperative symptoms on postoperative outcome is unknown.

METHODS AND RESULTS

The long-term outcome of 478 patients with organic mitral regurgitation (199 in NYHA functional class I/II and 279 in class III/IV before surgery) operated on between 1984 and 1991 was analyzed. In patients in NYHA class I/II before surgery compared with those in class III/IV, postoperative long-term survival was higher (at 10 years, 76+/-5% versus 48+/-4%, P<0.0001), with lower operative mortality (0.5% versus 5.4%, P=0.003) and better late survival (P<0.0001). Comparison of observed and expected survival showed identical curves in patients in class I/II before surgery (P=0.18), whereas excess mortality was observed in patients in class III/IV before surgery (P<0.0001). Excess mortality associated with severe symptoms was also confirmed in all subgroups (all P<0.003) and in multivariate analysis (P=0.0036; adjusted hazard ratio [95% CI], 1.81 [1.21 to 2.70]).

CONCLUSIONS

In patients with organic mitral regurgitation, preoperative functional class III/IV symptoms are associated with excess short- and long-term postoperative mortality independently of all baseline characteristics. These data should lead to consideration of surgical correction of severe organic mitral regurgitation when no or minimal symptoms are present in patients at low operative risk, especially if repair is feasible.

Excess mortality due to coronary artery disease after valve surgery. Secular trends in valvular regurgitation and effect of internal mammary artery bypass

BACKGROUND

During the 1980s, mortality from coronary artery disease (CAD) decreased markedly in the United States. This raises the question of whether a parallel decrease occurred in excess mortality due to CAD in patients undergoing surgical correction of valvular regurgitation.

METHODS AND RESULTS

Survival of 752 patients (age, 64 +/- 13 years) with isolated left-sided valvular regurgitation operated on from 1980 to 1991 was analyzed. Of 242 patients with CAD (stenosis > or = 70%), 208 had coronary artery bypass grafting. Multivariate analysis identified CAD as an independent predictor of operative mortality (odds ratio [OR] = 2.35, P = 0.012), overall (hazard ratio [HR] = 1.65, P < 0.0001) and late mortality (HR = 1.57, P = 0.0006), and postoperative congestive heart failure (HR = 2.35, P = 0.0001). Comparison of patients operated on in 1980 to 1985 with those operated on in 1986 to 1991, excess of operative, overall, and late mortality and postoperative congestive heart failure (adjusted for age and gender) related to associated CAD did not decrease significantly (P = 0.23, P = 0.64, P = 0.90, and P = 0.61, respectively). Overall survival was better for patients receiving an internal mammary artery graft than those receiving vein grafts only (HR = 0.57, P = 0.011).

CONCLUSIONS

In contrast to the secular trend for decreased mortality from CAD, excess mortality related to associated CAD after surgery for valvular regurgitation has not decreased. Internal mammary artery grafts were associated with improved outcome. In patients with valvular regurgitations, these results support continued active search of associated CAD, wide use of internal mammary artery graft, and vigorous efforts for secondary prevention of complications of CAD.

Mitral regurgitation: a new clinical perspective

Mitral regurgitation is a common valvular heart disease, particularly in the elderly population. The timing of surgical repair is controversial, but recent literature suggests a new clinical perspective on the management of this disease. Despite receiving medical treatment and having few initial symptoms, patients with mitral regurgitation due to flail leaflets have an excess mortality rate (6.3% per year) and high morbidity. Ten years after mitral regurgitation has been diagnosed, 90% of the patients have either died or undergone an operation. After surgical correction of mitral regurgitation, left ventricular dysfunction is a frequent complication and is the cause of excess heart failure and mortality. This complication is due to preoperative left ventricular dysfunction but is incompletely predictable with use of current methods. Conversely, considerable progress in surgery has resulted in an extremely low operative mortality rate (about 1% in patients younger than 75 years of age) and high feasibility of valve repair, even in patients with anterior leaflet prolapse. These facts have led to the new perspective that early surgical correction (before occurrence of overt symptoms or left ventricular dysfunction) should be considered when patients are diagnosed with severe mitral regurgitation.

Early surgery in patients with mitral regurgitation due to flail leaflets: a long-term outcome study

BACKGROUND

The optimal timing for surgery in patients with mitral regurgitation is disputed. Because of the frequency of left ventricular dysfunction, which is difficult to predict, early surgery has been recommended, but its potential benefits have not been demonstrated.

METHODS AND RESULTS

The outcomes of 221 patients (mean age, 65 +/- 13 years; 71% males) with flail leaflets diagnosed with two-dimensional echocardiography between 1980 and 1989 who were eligible for operation were analyzed. Group I comprised 63 patients who had early mitral valve surgery (within 1 month after diagnosis). Group II comprised 158 patients initially treated conservatively (80 of whom were operated on later). Group I patients were younger (P=.009), had more symptoms (P<.0001), and were more frequently in atrial fibrillation (P=.023) than group II patients. There was no difference in ejection fraction between the groups. The early surgery strategy was followed by an improved overall survival rate (P=.028) and a lower incidence of cardiovascular deaths (P=.025), congestive heart failure (P=.046), and new chronic atrial fibrillation (P=.032), as confirmed by multivariate analysis (adjusted risk ratios of 0.31, 0.18, 0.38, and 0.05, respectively; all P<.02).

CONCLUSIONS

In patients with mitral regurgitation due to flail leaflets, the strategy of early surgery versus conservative management is associated with an improved long-term survival rate, decreased cardiac mortality, and decreased morbidity after diagnosis. This outcome advantage suggests that early surgery is a reasonable treatment option to be considered in low-risk candidates with repairable valves and severe mitral regurgitation.

A population-based model of risk factors for ischemic stroke: Rochester, Minnesota

The medical record linkage system for the Rochester Epidemiology Project provided the means to identify 1,444 incidence cases of ischemic stroke and age- and sex-matched controls from the population from 1960 to 1984 to conduct a case-control study nested in the population. A multiple logistic-regression model permitted the estimation of odds ratios of ischemic stroke for each risk factor while adjusting for confounding variables. The final model, in addition to age and date of stroke, included transient ischemic attacks, hypertension, current smoking, atrial fibrillation, ischemic heart disease, mitral valve disease (other than prolapse), and diabetes mellitus. The process identified interactions showing that ischemic stroke incidence for persons with transient ischemic attacks was higher in women than in men and that the risk decreased with increasing age; that the risk of stroke with hypertension and also with current cigarette smoking decreased with increasing age; and that the risk of ischemic stroke with intermittent or persistent atrial fibrillation was similar when hypertension was present, but without hypertension the risk of stroke was more than seven times greater with persistent than with intermittent atrial fibrillation. None of the odds ratios differed over the five quinquennia of the study, and no effect of antihypertensive treatment on stroke incidence could be demonstrated in the population.

Clinical outcome of mitral regurgitation due to flail leaflet

BACKGROUND

Mitral regurgitation due to flail leaflet is difficult to manage, because it is frequently asymptomatic yet carries a high risk of left ventricular dysfunction and because the natural history of the condition is poorly defined.

METHODS

We obtained clinical follow-up data through 1994-1995 in 229 patients with isolated mitral regurgitation due to flail leaflet; this condition was first diagnosed by echocardiography between 1980 and 1989.

RESULTS

The 86 patients who were treated medically had a mortality rate significantly higher than expected (6.3 percent yearly, P=0.016 for the comparison with the expected rate in the U.S. population according to the 1990 census). Independent determinants of mortality were an older age, the presence of symptoms, and a lower ejection fraction. Patients who were even transiently in New York Heart Association functional class III or IV had a high mortality rate (34 percent yearly), but the rate was also notable (4.1 percent yearly) among those in class I or II. At 10 years, the mean (+/- SE) rates of heart failure, atrial fibrillation, and death or surgery were 63 +/- 8, 30 +/- 12, and 90 +/- 3 percent, respectively. In a multivariate analysis, surgical correction of mitral regurgitation (performed in 143 patients) was associated with a reduced mortality rate (hazard ratio, 0.29; 95 percent confidence interval, 0.15 to 0.56; P<0.001).

CONCLUSIONS

When treated medically, mitral regurgitation due to flail leaflet is associated with excess mortality and high morbidity. Surgery is almost unavoidable within 10 years after the diagnosis and appears to be associated with an improved prognosis; this finding suggests that surgery should be considered early in the course of the disease.

Contemporary practice of coronary revascularization in U.S. hospitals and hospitals participating in the bypass angioplasty revascularization investigation (BARI)

OBJECTIVES

To assess generalizability of the Bypass Angioplasty Revascularization Investigation (BARI), we conducted a separate study comparing revascularization in U.S. and BARI hospitals.

BACKGROUND

The BARI trial is a multicenter investigation comparing initial revascularization with percutaneous transluminal coronary angioplasty and coronary bypass graft surgery in patients with symptomatic multivessel coronary disease.

METHODS

All revascularization procedures during 5 consecutive workdays were surveyed at 75 U.S. hospitals offering coronary angioplasty and bypass surgery and at all BARI hospitals. Data collected were demographics, extent of disease and type of current and previous revascularization.

RESULTS

At both U.S. and BARI hospitals, 57% of all revascularization procedures were coronary angioplasty and 43% were bypass surgery. The U.S. hospitals had more patients with single-vessel disease, acute myocardial infarction and primary procedures. Other characteristics were similar. The majority of revascularization procedures were angioplasty for single-vessel disease (U.S. 32% vs. BARI 25%) and bypass surgery for triple-vessel disease (U.S. 31% vs. BARI 31%). Overall, the choice between bypass surgery and angioplasty was similar in BARI and U.S. hospitals (adjusted odds ratio [OR] 1.0, p = 0.914). However, older patients were more likely and younger patients less likely to undergo bypass surgery in BARI versus U.S. hospitals (older patients: adjusted OR 1.6, p = 0.031; younger patients: adjusted OR 0.6, p = 0.028). The BARI protocol would have excluded 65% of all candidates for revascularization, for whom indications already exist for angioplasty or bypass surgery, and another 23%, for whom angioplasty would be contraindicated for individual lesions.

CONCLUSIONS

Patients undergoing coronary revascularization in BARI and U.S. hospitals were generally similar, as was the choice between types of revascularization. Results from the BARI trial apply to approximately 300 (12%) candidates for coronary revascularization/workday.

Congestive heart failure after surgical correction of mitral regurgitation. A long-term study

BACKGROUND

In patients with mitral regurgitation, surgical intervention produces immediate improvement in symptoms, but the long-term incidence and significance of postoperative congestive heart failure are unknown.

METHODS AND RESULTS

The long-term outcome of 576 operative survivors of surgical correction of pure mitral regurgitation performed between 1980 and 1989 was analyzed. Survival was 77 +/- 2% and 56 +/- 3% at 5 and 10 years, respectively. Cumulative incidence of congestive heart failure was 23 +/- 2%, 33 +/- 3%, and 37 +/- 3% at 5, 10, and 14 years, respectively. Survival after the first episode of congestive heart failure was dismal, 44 +/- 4% at 5 years. Cause of congestive heart failure was left ventricular dysfunction in two thirds of the patients and valvular dysfunction in the other third. With multivariate analysis, the independent predictors of postoperative heart failure were preoperative ejection fraction (P = .0001), coronary artery disease (P = .0017), and New York Heart Association functional class (P = .012), with borderline value for atrial fibrillation (P = .10). The performance of valve repair was independently predictive of a lower incidence of the combined end point of death and heart failure (P = .001), compared with valve replacement.

CONCLUSIONS

Congestive heart failure frequently occurs late after surgical correction of mitral regurgitation and portends dismal prognosis. This complication is due most often to left ventricular dysfunction; its main determinant is decreased left ventricular function preoperatively. These data should lead to earlier indication of surgical correction of mitral regurgitation, before left ventricular dysfunction occurs.

Valve repair improves the outcome of surgery for mitral regurgitation. A multivariate analysis

BACKGROUND

Mitral valve repair has been suggested as providing a better postoperative outcome than valve replacement for mitral regurgitation, but this impression has been obscured by differences in baseline characteristics and has not been confirmed in multivariate analyses.

METHODS AND RESULTS

The outcomes in 195 patients with valve repair and 214 with replacement for organic mitral regurgitation were compared using multivariate analysis. All patients had preoperative echocardiographic assessment of left ventricular function. Before surgery, patients with valve repair were less symptomatic than those with replacement (42% in New York Heart Association functional class I or II versus 24%, respectively; P = .001), had less atrial fibrillation (41% versus 53%; P = .017), and had a better ejection fraction (63 +/- 9% versus 60 +/- 12%, P = .016). After valve repair, compared with valve replacement, overall survival at 10 years was 68 +/- 6% versus 52 +/- 4% (P = .0004), overall operative mortality was 2.6% versus 10.3% (P = .002), operative mortality in patients under age 75 was 1.3% versus 5.7% (P = .036), and late survival (in operative survivors) at 10 years was 69 +/- 6% versus 58 +/- 5% (P = .018). Late survival after valve repair was not different from expected survival. After surgery, ejection fraction decreased significantly in both groups but was higher after valve repair (P = .001). Multivariate analysis indicated an independent beneficial effect of valve repair on overall survival (hazard ratio, 0.39; P = .00001), operative mortality (odds ratio, 0.27; P = .026), late survival (hazard ratio, 0.44; P = .001), and postoperative ejection fraction (P = .001).

CONCLUSIONS

Valve repair significantly improves postoperative outcome in patients with mitral regurgitation and should be the preferred mode of surgical correction. The low operative mortality is an incentive for early surgery before ventricular dysfunction occurs.

Echocardiographic prediction of left ventricular function after correction of mitral regurgitation: results and clinical implications

OBJECTIVES

This study attempted to determine the incidence, prognosis and predictability of postoperative left ventricular dysfunction in patients undergoing correction of mitral regurgitation.

BACKGROUND

Left ventricular function in patients with mitral regurgitation is altered by loading conditions and is difficult to assess. Predictive value of preoperative variables on postoperative left ventricular function and the role of echocardiography are uncertain.

METHODS

In 266 patients undergoing correction of mitral regurgitation between 1980 and 1989, left ventricular function was echocardiographically assessed preoperatively (within 6 months) and postoperatively (within 1 year).

RESULTS

After correction of mitral regurgitation, left ventricular ejection fraction decreased significantly ([mean +/- SD] 50% +/- 14% vs. 58% +/- 13%, p < 0.0001). Postoperative left ventricular dysfunction (ejection fraction < 50%) was frequent (41% of patients) and carried a poor prognosis (at 8 years survival, 38% +/- 9% vs. 69% +/- 8%, p < 0.0001). Four preoperative echocardiographic variables showed good correlation with postoperative ejection fraction: preoperative ejection fraction (r = -0.70), systolic diameter (r = -0.63), diameter/thickness ratio (r = -0.64) and end-systolic wall stress (r = -0.62) (all p < 0.0001). With multivariate analysis, ejection fraction (p = 0.0001) and systolic diameter (p = 0.0005) were independent predictors of postoperative ejection fraction, and angiographic variables provided no incremental predictive power. In addition to echocardiographic variables, recent regurgitation, functional class and coronary artery disease were also independent predictors of postoperative ejection fraction.

CONCLUSIONS

After surgical correction of mitral regurgitation, left ventricular dysfunction is frequent and carries a poor prognosis. Postoperative ejection fraction can be predicted by echocardiographic preoperative ejection fraction and systolic diameter. Recent onset of regurgitation, mild or no symptoms, and absence of coronary artery disease are independent and favorable predictors of postoperative ejection fraction. These results should lead to consideration of surgical correction at an earlier stage.

Gender differences in left ventricular functional response to aortic valve replacement

BACKGROUND

To characterize gender differences in recovery of ventricular function and survival after aortic valve replacement (AVR), baseline characteristics related to outcome were analyzed in 1012 consecutive patients (329 women and 683 men) undergoing AVR in 1983 through 1990.

METHODS AND RESULTS

Seventy-seven percent of patients had aortic stenosis (AS), 11% insufficiency (AI), and 12% mixed AS/AI; 42% underwent concomitant coronary artery bypass. Women as a group had a greater mean age (P < .0001), had AS more frequently than AI or AS/AI (P < .01), had coronary disease less frequently (P < .01), and had a higher preoperative left ventricular ejection fraction (EF) (P < .0001), although preoperative New York Heart Association (NYHA) functional class was similar (P = NS) compared with men. Male sex (P < .0001), advanced age (P < .0003), AI rather than AS (P < .01), and greater extent of coronary disease (P < .04) were independently associated with lower preoperative EF. Women with coronary disease were as likely as men (P = NS) to undergo concomitant coronary bypass, and completeness of revascularization did not differ (P = NS) by gender. Observed survival probabilities after AVR (expressed as 30-day/5-year) were .97/.81 overall, .94/.77 for women, and .98/.83 for men (P < .02). Cox model analysis showed advanced age, decreased preoperative EF, greater extent of coronary disease, requirement for annular enlargement, smaller prosthetic valve size, and advanced NYHA class (all P < .04) but neither female sex nor smaller body surface area (both P = NS) as multivariate risk factors for overall mortality. In 664 patients (66%), postoperative EF was measured a mean 1.4 years after AVR. In patients with preoperative EF < or = 45% (n = 167), the change in EF after AVR was greater (P < .02) in women (from 33 +/- 8% to 48 +/- 15%, P < .001) than in men (from 32 +/- 9% to 42 +/- 15%, P < .001). By multivariate regression analysis, female sex (P < .02) and lesser extent of coronary disease (P < .05) were independent predictors of early improvement in EF. Improvement in EF conveyed an independent subsequent survival benefit to both women (P < .03) and men (P < .001), and the magnitude of benefit did not differ (P = .4) between the two groups.

CONCLUSIONS

These data suggest that gender-related factors importantly influence the adaptive and recovery response of the left ventricle to pressure and volume overload. However, gender differences in LV adaptation do not influence survival after AVR.

Echocardiographic prediction of survival after surgical correction of organic mitral regurgitation

BACKGROUND

Left ventricular dysfunction is a frequent cause of death after successful surgical repair of mitral regurgitation. The role of preoperative echocardiographic left ventricular variables in the prediction of postoperative survival and thus their clinical implications remain uncertain.

METHODS AND RESULTS

The survival of 409 patients operated on between 1980 and 1989 for pure, isolated, organic mitral regurgitation and with a preoperative echocardiogram (within 6 months of operation) was analyzed. The overall survival was 75% at 5 years (90% of expected), 58% at 10 years (88% of expected), and 44% at 12 years (73% of expected). Operative mortality was 6.6% and markedly improved from 1980 to 1984 (10.7%) to 1985 to 1989 (3.7%). Multivariate analysis showed that age (P = .0003), date of operation (P = .003), and functional class (P = .016) but not left ventricular function were predictors of operative mortality. In the most recent period (1985 to 1989), operative mortality was 12.3% in patients age 75 years or older and 1.1% in patients younger than 75 years. Late survival was analyzed in the operative survivors. Multivariate analysis showed that the most powerful predictor was echocardiographic ejection fraction (EF) (P = .0004), followed by age (P = .0031), creatinine level (P = .0062), systolic blood pressure (P = .0164), and presence of coronary artery disease (P = .0237). The late survival at 10 years was 32 +/- 12% for patients with EF < 50%, 53 +/- 9% for EF 50% to 60%, and 72 +/- 4% for EF > or = 60%. The hazard ratio compared with EF > or = 60% was 2.79 (95% confidence interval, 1.65 to 4.72) for EF < 50% and 1.81 (95% confidence interval, 1.11 to 2.95) for EF 50% to 60%. Echocardiographic EF remained the best predictor of late survival, even when combined with left ventricular angiographic variables. The survival of patients with EF > or = 60% was 100% of expected at 10 years but was better in patients in class I or II than in those in class III or IV (82 +/- 6% versus 59 +/- 6%, respectively, at 10 years; P = .0021). The preoperative predictors of operative and late mortality remained significant independent of the type of surgical correction performed in combined multivariate analyses.

CONCLUSIONS

In organic mitral regurgitation, (1) operative mortality has markedly decreased recently, being at a low 1.1% in patients younger than 75 years, and is predicted by age and symptoms and not by left ventricular function, and (2) left ventricular EF measured by echocardiography is the most powerful predictor of late survival. These results suggest that surgical treatment should be considered early, even in the absence of severe symptoms, in patients with severe mitral regurgitation, before left ventricular dysfunction occurs.

Determinants of survival and recovery of left ventricular function after aortic valve replacement

To determine factors that influence survival and recovery of ventricular function in patients undergoing aortic valve replacement in the current surgical era, baseline risk factors related to outcome were analyzed in 1,012 consecutive patients undergoing aortic valve replacement between 1983 and 1990. Forty-two percent of patients underwent concomitant coronary bypass. Observed survival probabilities (expressed as 30-day/5-year) were 0.97/0.81 overall, 0.99/0.89 for patients aged less than 70 years, and 0.95/0.74 for patients aged 70 years or greater. Advanced age (p < 0.0001), decreased ejection fraction (p < 0.0001), extent of coronary disease (p < 0.006), smaller prosthetic valve (p < 0.03), and advanced New York Heart Association class (p < 0.04) were incremental risk factors for mortality. In patients with preoperative ventricular dysfunction (ejection fraction < or = 0.45), ejection fraction measured 1.4 years after aortic valve replacement improved in 72% and the mean increment in ejection fraction was 0.175 (95% confidence interval, 0.154 to 0.195). The increment in ejection fraction was greater in female patients than in male patients (p < 0.02) and greater in patients without than with coronary disease (p < 0.02). Female sex (p < 0.02) and lesser extent of coronary disease (p < 0.05) were independent predictors of change in ejection fraction. In all patients, early improvement in ejection fraction conveyed an independent subsequent survival benefit (p < 0.0001). The results of aortic valve replacement in the current era are excellent, and the majority of patients with ventricular dysfunction demonstrate significant improvement. Early improvement in ejection fraction, influenced by coexistent coronary artery disease and sex-associated factors, importantly affects subsequent survival.

Keeping hostility in perspective: coronary heart disease and the Hostility Scale on the Minnesota Multiphasic Personality Inventory

Three prospective studies from the early 1980s found that high scores on the Hostility (Ho) Scale of the Minnesota Multiphasic Personality Inventory (MMPI) were associated with an increased incidence of coronary heart disease (CHD) and mortality from CHD and other causes. In the current study, the association between the Ho score and subsequent health status was examined in a 20-year follow-up of 620 general medical patients who completed the MMPI between 1962 and 1965. Univariately, the Ho score from the MMPI was a significant factor for predicting the development of CHD, CHD-related mortality, and total mortality. When two simple risk factors for CHD--age and sex--were also considered, however, the MMPI Ho score was no longer a significant predictive factor.

Long-term follow-up of patients undergoing closed transventricular mitral commissurotomy: a useful surrogate for percutaneous balloon mitral valvuloplasty?

OBJECTIVE

The aim of this study was to determine the long-term outcome and multivariate predictors of late events in patients who underwent transventricular mitral commissurotomy at the Mayo Clinic in the early 1960s.

BACKGROUND

Percutaneous balloon mitral valvuloplasty is an important new procedure for which long-term follow-up data are not yet available. However, such data do exist for patients who have undergone transventricular mitral commissurotomy, a similar but older and more invasive procedure.

METHODS

Follow-up data (mean duration 13.9 years) for 207 women and 60 men who underwent transventricular mitral commissurotomy were obtained from medical records, referring physicians, questionnaires and telephone interviews. Survival and survival free of repeat commissurotomy or mitral valve surgery were estimated with the Kaplan-Meier method. Cox proportional hazards model was used to determine predictors of survival and repeat mitral valve surgery.

RESULTS

Postoperatively, 92% of patients had symptomatic improvement, which was sustained for at least 3 to 4 years in 78%. At 10, 15 and 20 years postoperatively, 79%, 67% and 55%, respectively, of patients were alive and 57%, 36% and 24%, respectively, were alive and free of repeat mitral valve surgery. At 10 years, 90% of all patients were free of transient or fixed cerebrovascular events. In multivariate analyses, atrial fibrillation, age and male gender were independently associated with death, whereas mitral valve calcification, cardiomegaly and mitral regurgitation independently predicted repeat mitral valve surgery.

CONCLUSIONS

Long-term results after transventricular mitral commissurotomy are excellent in selected patients with symptomatic mitral stenosis. Because of similarities in patient selection and mechanisms of mitral valve dilation, similar favorable long-term outcomes may be expected after percutaneous balloon mitral valvuloplasty.

Relationship of cardiac disease to stroke occurrence, recurrence, and mortality

BACKGROUND AND PURPOSE

This is a study of cardiac diseases associated with the 1,382 cases of first cerebral infarction in residents of Rochester, Minn., during 1960-1984.

METHODS

This is a population-based study in Rochester, Minn., for which the medical record-linkage system was used to identify cardiac disease among patients with first cerebral infarction.

RESULTS

There were 318 patients (23%) who had at least one major potential cardiac source of emboli. The proportion of patients with a cardiac source of emboli was significantly higher among patients older than age 75 years (29%) than among younger patients (17%). The 30-day stroke recurrence rate among patients with a cardiac source of emboli (2%) was not significantly different than that among those without a cardiac source of emboli (2%). Among patients with a cardiac source of emboli, there was no difference in the probability of stroke at 30 days and at 90 days for those treated or not treated with anticoagulants. During the first 30 days after cerebral infarction, the risk of death in patients with a cardiac source of emboli (23%) was 14 times that of recurrent stroke. The risk of death at 30 days in patients without a cardiac source of emboli was 8%.

CONCLUSIONS

Significant independent predictors of death (Cox proportional-hazards analysis) were age, prior myocardial infarction, atrial fibrillation present at onset of stroke, congestive heart failure before the stroke, and an age x congestive heart failure interaction. The only significant independent predictors of recurrent stroke were cardiac valve disease and congestive heart failure.

Stroke in coronary artery bypass graft surgery: an analysis of the CASS experience. The participants in the Coronary Artery Surgery Study

An analysis of the Coronary Artery Surgery Registry (CASS) was performed to determine the occurrence of stroke after coronary artery bypass surgery in patients entered into the Coronary Artery Surgery Study Registry. Of the 10,098 patients having coronary artery bypass surgery at the Coronary Artery Surgery Study participating sites during the period July 1974 through May 1979, a total of 348 patients (or 3.4%) sustained a stroke during the first year after coronary bypass surgery. Fifty-nine strokes occurred on the day of surgery, and an additional 129 strokes occurred during hospitalization for coronary bypass surgery. Thus, 188 patients (1.9%) of the entire surgical group sustained a stroke during initial hospitalization for coronary artery bypass surgery. Logistic regression analysis was used to predict stroke on the day of surgery, during the hospitalization for surgery, and during the first year after surgery. The most powerful predictors of stroke on the day of coronary artery bypass surgery were: 1) older age (n = less than 0.0001); 2) use of alpha-adrenergic drugs after bypass (n = 0.0001); and 3) longer duration of cardiopulmonary bypass (n = 0.002). For those strokes occurring at least 1 day after coronary artery bypass but during the initial hospitalization, age and duration of cardiopulmonary bypass were the most powerful predictors of stroke. An analysis of predictors of stroke within 1 yr after hospital dismissal for initial coronary bypass surgery revealed that the most powerful predictor was a history of previous cerebrovascular disease (n less than 0.0001) and a history of hypertension (n less than 0.0001).(ABSTRACT TRUNCATED AT 250 WORDS)

Some comments on the indications for the coronary artery bypass graft operation

Although the indications for coronary artery bypass grafting are clear in some subsets of patients (left main coronary artery, 3-vessel disease with impaired left ventricular function), in others considerable uncertainty persists and is related to lack of sufficient information for making patient specific comparisons of outcomes after competing forms of treatment. These comparisons need to be time related, and to emphasize not only the treatment providing the most favorable outcome, but also the magnitude of the difference in outcome as well as the degree of certainty that the difference is not related to chance alone. With appropriate data, analyses can be performed to provide highly useful patient specific comparisons of outcomes after competing forms of treatment. Such predictions and comparisons suggest the possibility that coronary artery bypass grafting would ideally be indicated while left ventricular function remains good but extensive 3-vessel disease exists. In the future, emergency coronary artery bypass grafting operations, and other special modes for myocardial management, may play a more frequent role in preserving left ventricular function in patients with acute myocardial infarctions.

The potential contribution of cardiac replacement to the control of cardiovascular diseases. A population-based estimate

The potential number of individuals who might benefit from a cardiac replacement procedure (either cardiac transplantation or insertion of a total artificial heart) was retrospectively estimated from medical records for residents of Olmsted County, Minnesota, who had died during a 5-year period. Residents were divided into two age groups: those younger than 15 years (pediatric) and those 15 to 69 years (adult). During the 5-year period of observation, cardiac disease led to death in 17 of the 8342 live births in Olmsted County. Cardiac disease also caused the deaths of 248 adults meeting the age criteria. Five children and 35 adults met all criteria for cardiac replacement. Extrapolation to the total population of the United States suggests that 2167 children (a 95% confidence interval of 361 to 3972) and 16,500 adults (a 95% confidence interval of 11,456 to 22,959) per year could potentially benefit from cardiac replacement.