The relationship between the metabolic syndrome defined by various criteria and the extent of coronary artery disease

The association between the severity of coronary artery disease (CAD) and metabolic syndrome (MS) as defined by recently proposed criteria remains unknown. Therefore, we investigated the association between the severity of CAD and MS based on four sets of criteria. The frequency of MS and the severity of CAD determined using the Gensini score (GS) were assessed in 656 consecutive patients who underwent elective coronary angiography for the first time. Using the various criteria, 25.4% of males and 25.6% of females fulfilled the NCEP-ATPIII criteria, 46.6% of males and 21.3% of females fulfilled the International Diabetes Federation (IDF) criteria, 44.0% of males and 41.9% of females fulfilled the American Heart Association/National Heart, Lung, and Blood Institute (AHA/NHLBI) criteria, and 42.5% of males and 18.8% of females fulfilled the Japanese definition. On multivariate analysis, MS defined according to the AHA/NHLBI criteria was related to an increased risk of extensive CAD in males [odds ratio (OR) 1.89, p=0.001]. MS defined according to the IDF criteria was associated with the highest risk for extensive CAD in females (OR 2.83, p=0.019). In conclusion, MS was found to be associated with the extent of CAD. However, gender-specific differences and MS definition-specific differences exist.

The adverse prognostic significance of the metabolic syndrome with and without hypertension in patients who underwent complete coronary revascularization

OBJECTIVES

The metabolic syndrome is associated with high risk for long-term coronary artery disease mortality. However, few studies have examined the prognostic importance of the metabolic syndrome with and without hypertension.

METHODS

The data of 1133 nondiabetic patients who underwent complete revascularization were analyzed. The patients were categorized by the presence of the metabolic syndrome using the modified American Heart Association/National Heart, Lung, and Blood Institute statement and by the presence of hypertension. All patients were divided into four groups: neither the metabolic syndrome nor hypertension (group 1); the metabolic syndrome without hypertension (group 2); hypertension without the metabolic syndrome (group 3); and both the metabolic syndrome and hypertension (group 4). Cox proportional hazards were used in adjusted analyses for all-cause and cardiac mortality, as well as for the composite incidence of fatal and nonfatal stroke.

RESULTS

The progress of 276 (24.4%) patients in group 1, 413 (36.5%) in group 2, 105 (9.3%) in group 3, and 339 (29.9%) in group 4 was analyzed. The mean follow-up was 10.4 +/- 3.4 years. Patients in group 4 had a higher risk of all-cause mortality (hazard ratio 1.78, P = 0.004). In addition, patients in groups 2 and 4 had a higher risk of cardiac mortality (group 2: hazard ratio 2.84, P = 0.04, group 4: hazard ratio 3.91, P = 0.001) and stroke (group 2: hazard ratio 2.46, P = 0.03, group 4: hazard ratio 2.09, P = 0.03).

CONCLUSION

The metabolic syndrome both with and without hypertension is associated with increased risk of cardiac mortality and stroke incidence in patients who underwent complete coronary revascularization.

Relationship between the metabolic syndrome and the incidence of stroke after complete coronary revascularization over a 10-year follow-up period

OBJECTIVES

The prevalence of the metabolic syndrome, regarded as an important risk factor for coronary artery disease and stroke, is growing. However, the association between the metabolic syndrome and stroke, particularly in patients following coronary revascularization, remains unknown. Therefore, the relationship between the metabolic syndrome and stroke was examined among patients who had achieved complete coronary revascularization.

METHODS

1836 consecutive patients who had achieved complete revascularization from 1984 to 1992 were studied. The patients were categorized according to the presence or absence of the metabolic syndrome using the modified AHA/NHLBI statement (obesity was defined as a body mass index >or=25 kg/m(2)). Multivariate Cox proportional hazards regression was used for adjusted analyses for all-cause and cardiac mortality, as well as for the incidence of fatal and non-fatal stroke.

RESULTS

The progress of 826 (45.0%) patients with the metabolic syndrome and 1010 (55.0%) patients without the metabolic syndrome was analyzed. The mean follow-up was 11.4+/-2.9 years. Overall, there were 130 (7.1%) strokes, and the risk of stroke was significantly higher in patients with metabolic syndrome than in those without metabolic syndrome (HR 1.3; 95% CI 1.0-2.1; P=0.045).

CONCLUSION

The presence of the metabolic syndrome is a significant predictor of stroke, as well as all-cause and cardiac mortality, among patients who achieve complete coronary revascularization.

The impact of pravastatin therapy on long-term outcome in patients with metabolic syndrome undergoing complete coronary revascularization

BACKGROUND

Few studies dealing with the efficacy of statin therapy among patients with metabolic syndrome (MS) and coronary artery disease (CAD) have been conducted. In particular, there have been no studies of the efficacy of statins among Asian MS patients with treated CAD.

METHODS AND RESULTS

Data from 1,138 consecutive patients who underwent complete revascularization (coronary intervention or bypass surgery) were collected. Of these, 529 patients who satisfied the criteria for MS using the American Heart Association/National Heart, Lung and Blood Institute statement (body mass index >or=25 was used instead of waist circumference) were assessed. All-cause and cardiovascular mortality of patients given statins and those not given statins at least 2 weeks before the complete revascularization were compared. To adjust for the variables that would have been related to the decision to give statins, the propensity score was calculated, and multivariate Cox regression was carried out. Statins were given to 146 patients. During follow-up (9.1 +/-2.5 years), 104 patients died. On multivariate analysis, statin use was significantly associated with reduced all-cause (hazard ratio (HR) 0.56, 0.31-0.99; P=0.049) and cardiovascular (HR 0.53, 0.30-0.96; P=0.042) mortality.

CONCLUSIONS

In patients with MS and CAD, statins given at least 2 weeks before the complete revascularization, was associated with a reduced risk of all-cause and cardiovascular mortality.

Prognostic significance of glomerular filtration rate estimated by the Japanese equation among patients who underwent complete coronary revascularization

An equation that accurately estimates the glomerular filtration rate (GFR) in the Japanese population has been proposed; however, the prognostic significance of estimated GFR (eGFR) defined according to this equation has not been reported. In addition, the prognostic significance of eGFR during long-term follow-up after complete coronary revascularization remains unclear. We assessed the prognostic significance of eGFR values, estimated by the new Japanese equation, in a cohort of patients following complete coronary revascularization. We studied consecutive patients with complete revascularization from 1984 to 1992. Patients on dialysis were excluded. A novel Japanese equation was used to estimate the GFR: eGFR=194×(serum creatinine)(-1.094)×(age)(-0.287)(×0.739 if female). Multivariate Cox proportional hazards regression analyses were performed to determine all-cause and cardiac mortality. We analyzed data of 1809 patients, of whom 571 (31.6%) had an eGFR of ≥90 mlmin(-1) per 1.73 m(2), 917 (50.7%) had an eGFR of 60-89 mlmin(-1) per 1.73 m(2), 298 (16.5%) had an eGFR of 30-59 mlmin(-1) per 1.73 m(2) and 23 (1.3%) had an eGFR of <30 mlmin(-1) per 1.73 m(2). During follow-up (11.4±2.9 years), there were 397 (22.0%) all-cause and 123 (6.8%) cardiac deaths overall. Patients with an eGFR of 30-59 mlmin(-1) per 1.73 m(2), and <30 mlmin(-1) per 1.73 m(2) revealed significantly greater risk of all-cause mortality than those with eGFR of ≥90 mlmin(-1) per 1.73 m(2) (hazard ratio (HR) 1.91, P<0.001, HR 3.35, P<0.001, respectively). Furthermore, incidence of cardiac death was higher in patients with an eGFR of 30-59 mlmin(-1) per 1.73 m(2) than those with an eGFR of ≥90 mlmin(-1) per 1.73 m(2) (HR 2.89, P<0.001). GFR as estimated using the new Japanese equation had a prognostic significance among patients with complete coronary revascularization.

Comparison of the Apnea-Hypopnea Index Determined by a Peripheral Arterial Tonometry-Based Device With That Determined by Polysomnography - Results From a Multicenter Study

Background: Sleep disordered breathing (SDB) is prevalent and associated with increased mortality in patients both with and without cardiovascular disease (CVD). Many portable monitoring devices, including peripheral arterial tonometry (PAT)-based devices, have been developed. Although previous studies have demonstrated that the apnea-hypopnea index (AHI) determined by PAT devices (pAHI) is strongly correlated with AHI determined by polysomnography (AHI-PSG), no data have been reported from a Japanese patient population or patients with CVD. In this study we compared the parameters determined by PAT-based devices with those determined by polysomnography in Japanese patients with CVD. Methods and Results: We enrolled 120 patients undergoing overnight polysomnography at 6 Japanese centers. A PAT-based device was used simultaneously with polysomnography. Polysomnography recordings were scored centrally by a technician in a blinded manner. PAT-based device recordings were scored using an automatic algorithm. There was a strong correlation between pAHI and AHI-PSG (r=0.896; P<0.001) with acceptable agreement. The strong correlation between pAHI and AHI-PSG was observed in patients with CVD (n=55; P=0.849; P<0.001) and without CVD (n=65; r=0.927; P<0.001). The presence or absence of CVD did not affect the relationship between pAHI and AHI-PSG (P=0.225). Conclusions: A PAT-based device provides a reliable AHI in a Japanese patient population, even in patients with CVD. These findings may help reduce the number of patients with undiagnosed SDB and CVD.

Fluid Retention and Rostral Fluid Shift in Sleep-Disordered Breathing

Sleep-disordered breathing (SDB) is common and adversely affects cardiovascular morbidity and mortality. Despite multifactorial pathogenesis, SDB is prevalent in patients with fluid retention disorders, such as drug-resistant hypertension, end-stage renal disease, and heart failure, suggesting that fluid retention may play a role in the pathogenesis of SDB. During the day, fluid is likely to accumulate in the legs, and upon lying down at night is displaced from the legs. Many data suggest that some of this fluid displaced from the legs may redistribute to the upper body and predispose to SDB. This review article will highlight evidence for a relationship between SDB and fluid retention or rostral fluid shift, and discuss mechanisms that link them.

Inverse relationship of subjective daytime sleepiness to mortality in heart failure patients with sleep apnoea

AIMS

Patients with sleep apnoea (SA) and heart failure (HF) are less sleepy than SA patients without HF. HF and SA both increase sympathetic nervous system activity (SNA). SNA can augment alertness. We previously showed that in HF patients, the degree of daytime sleepiness was not related to the severity of SA but was inversely related to SNA. Elevated SNA is associated with increased mortality in HF. Therefore, we hypothesized that in HF patients with SA, the degree of daytime sleepiness will be inversely related to mortality.

METHODS AND RESULTS

In a prospective cohort study, 218 consecutive patients with systolic HF had overnight polysomnography. Among them, 80 subjects with SA (apnoea-hypopnoea index ≥15) were followed for a mean of 28 months to determine all-cause mortality rate. Subjective daytime sleepiness was assessed by the Epworth Sleepiness Scale (ESS). During follow-up, 20 patients died. The 5 year death rate in patients with ESS less than 6 (i.e. less sleepy) was significantly higher than in patients with an ESS at or above the median of 6 (i.e. sleepier) [21.3 deaths/100 patient-years vs. 6.2 deaths/100 patient-years, unadjusted hazard ratio (HR) 2.94, 95% confidence interval (CI) 1.20 to 7.20, P = 0.018]. After adjusting for confounding factors that included sex, history of hypertension, and mean arterial oxyhaemoglobin saturation, compared with the sleepier patients, less sleepy patients had greater risk of mortality (HR 2.56, 95% CI 1.01 to 6.47, P = 0.047). As a continuous variable, ESS scores were inversely related to mortality risk (HR 0.86, 95% CI 0.75 to 0.98, P = 0.022).

CONCLUSIONS

In patients with HF and SA, the degree of subjective daytime sleepiness is inversely related to the mortality risk, suggesting that among HF patients with SA, those with the least daytime sleepiness are at greater risk of death. They may therefore have greater potential for mortality benefit from therapy of SA than those with greater daytime sleepiness.

Propensity analysis of 12 years outcome after bypass graft or balloon angioplasty in patients with multivessel coronary artery disease

BACKGROUND

Randomized trials have shown that long-term mortality rates are similar between patients with multivessel coronary artery disease (CAD) treated by percutaneous coronary intervention (PCI) and by coronary artery bypass graft (CABG). However, there are scant data regarding more than 10 years long-term follow-up in Asian populations. Therefore, we performed a pooled analysis of our observational data evaluating long-term outcomes of PCI as compared with CABG in patients with multivessel disease among a Japanese population.

METHODS AND RESULTS

We enrolled 1364 patients, of whom 225 (16.5%) and 1139 (83.5%) underwent PCI and CABG, respectively. During follow-up (12.8±3.4 years), 377 patients died (cardiac death, 125; cardiovascular death, 177) and 322 underwent revascularization. We predicted the probability of undergoing PCI using propensity analysis. After adjusting for baseline variables including propensity score, PCI and CABG did not differ in terms of all-cause (hazard ratio (HR) 1.12; 95% confidence interval (CI) 0.72-1.73; p=0.62), cardiac (HR 0.62; 95%CI 0.32-1.23; p=0.17), and cardiovascular mortality (HR 0.83; 95%CI 0.45-1.52; p=0.54). However, the incidence of revascularization was significantly higher in the PCI group than in the CABG group (HR 0.20; 95%CI 0.15-0.28; p<0.0001).

CONCLUSION

Although PCI was associated with a significantly higher risk of revascularization than CABG, long-term mortality rates did not significantly differ between the two procedures in this oriental population.