Relative predictive value of intraventricular dysynchrony in determining long-term outcome in patients with known or suspected coronary disease

Improvement of intra-ventricular dysynchrony (IVD) in pts undergoing bi-ventricular pacing is associated with clinical improvementbut little isknownabout the relationship between IVD and prognosis.We sought whether IVD influences long-term outcome in pts with known or suspected coronary disease (CAD). Tissue Doppler imaging was performed in 184 pts (aged 61±10 years, 67% male) prior to dobutamine echo. From velocity curves the interval between QRS onset and max systolic velocity (Ts) was measured in basal septal, lateral, inferior and anterior segments. The maximal difference in Ts between segments (TsMax) was used as a measure of IVD. The standard deviation (TsSD) between all segments and the septal-lateral difference (TsSL) were also calculated. Pts were followed up for a median interval of 5 years and a Cox model used for survival analysis. The medianwall motion index (WMI) was 1.3 (IQR 1.0–1.8) at rest and 1.4 (IQR 1.3–1.9) at stress. The table shows IVD parameters. Forty-one deaths occurred during follow-up. Pts who died during follow-up, compared to survivors, showed greater IVD. WMI at rest (p = 0.03) and peak stress (p = 0.02), TsSD (p = 0.06), TsSL (p = 0.02) and TsMax (p = 0.05) but not QRS width were univariate predictors of mortality. TsSL was the only independent predictor of death (p = 0.01). Therefore, IVD is common in pts with known or suspected CAD. Pts with more IVD have reduced long-term survival, independent of WMI.

Incremental benefit of myocardial contrast to combined dipyridamole-exercise stress echocardiography for the assessment of coronary artery disease

Background-Although assessment of myocardial perfusion by myocardial contrast echocardiography (MCE) is feasible, its incremental benefit to stress echocardiography is not well defined. We examined whether the addition of MCE to combined dipyridamole-exercise echocardiography (DExE) provides incremental benefit for evaluation of coronary artery disease (CAD). Methods and Results-MCE was combined with DExE in 85 patients, 70 of whom were undergoing quantitative coronary angiography and 15 patients with a low probability of CAD. MCE was acquired by low-mechanical-index imaging in 3 apical views after acquisition of standard resting and poststress images. Wall motion, left ventricular opacification, and MCE components of the study were interpreted sequentially, blinded to other data. Significant (>50%) stenoses were present in 43 patients and involved 69 coronary territories. The addition of qualitative MCE improved sensitivity for the detection of CAD (91% versus 74%, P=0.02) and accurate recognition of disease extent (87% versus 65% of territories, P=0.003), with a nonsignificant reduction in specificity. Conclusions-The addition of low-mechanical-index MCE to standard imaging during DExE improves detection of CAD and enables a more accurate determination of disease extent.

White blood cell count predicts reduction in coronary heart disease mortality with pravastatin

Background-Elevated serum inflammatory marker levels are associated with a greater long-term risk of cardiovascular events. Because 3-hydroxy-3-methylglutaryl coenzyme-A reductase inhibitors (statins) may have an antiinflammatory action, it has been suggested that patients with elevated inflammatory marker levels may have a greater reduction in cardiovascular risk with statin treatment. Methods and Results-We evaluated the association between the white blood cell count (WBC) and coronary heart disease mortality during a mean follow-up of 6.0 years in the Long-Term Intervention With Pravastatin in Ischemic Disease (LIPID) Study, a clinical trial comparing pravastatin (40 mg/d) with a placebo in 9014 stable patients with previous myocardial infarction or unstable angina. An increase in baseline WBC was associated with greater coronary heart disease mortality in patients randomized to placebo (hazard ratio for 1 X 10(9)/L increase in WBC, 1.18; 95% CI, 1.12 to 1.25; P<0.001) but not pravastatin (hazard ratio, 1.02; 95% CI, 0.96 to 1.09; P=0.56; P for interaction=0.004). The numbers of coronary heart disease deaths prevented per 1000 patients treated with pravastatin were 0, 9, 30, and 38 for baseline WBC quartiles of <5.9, 6.0 to 6.9, 7.0 to 8.1, and >8.2X10(9)/L, respectively. WBC was a stronger predictor of this treatment benefit than the ratio of total to high-density lipoprotein cholesterol and a global measure of cardiac risk. There was also a greater reduction (P=0.052) in the combined incidence of cardiovascular mortality, nonfatal myocardial infarction, and stroke with pravastatin as baseline WBC increased ( by quartile: 3, 41, 61, and 60 events prevented per 1000 patients treated, respectively). Conclusions-These data support the hypothesis that individuals with evidence of inflammation may obtain a greater benefit from statin therapy.

Contribution of changes in risk factors to the decline of coronary heart disease mortality in Australia over three decades

BACKGROUND: Coronary heart disease has been a major cause of mortality in Australian adults, but the rate has declined by 83% from the 1968 peak by the year 2000. The study objective is to determine the contribution of changes in population risk factors - mean serum cholesterol and diastolic blood pressure and tobacco smoking prevalence - to the decline in coronary heart disease mortality in Australia over three decades. METHODS: Coronary heart disease deaths (International Classification of Disease-9, 410-414) and population by year, age group and sex were obtained from the Australian Bureau of Statistics. Risk factor levels were obtained from population surveys and estimated average annual changes by period were used to calculate average annual 'attributable' proportional declines in CHD mortality by period (age 35-64 years). RESULTS: Over the period 1968-2000, 74% of male decline and 81% of the female decline in coronary heart disease mortality rate was accounted for by the combined effect of reductions in the three risk factors. In males 36% of the decline was contributed by reductions in diastolic blood pressure, 22% by cholesterol and 16% by smoking. For females 56% was from diastolic blood pressure reduction, 20% from cholesterol and 5% from smoking. Effects of reductions in serum cholesterol on coronary heart disease mortality occurred mainly in the 1970s. Declines in diastolic blood pressure had effects on coronary heart disease mortality over the three decades, and declines in tobacco smoking had a significant effect in males in the 1980s. CONCLUSION: Most of the spectacular decline in coronary heart disease mortality over the last three decades in Australia can be ascribed to reductions in population risk factors from primary and secondary prevention.

Effect of pravastatin on cardiovascular events in people with chronic kidney disease

Background - Limited data describe the cardiovascular benefit of HMG-CoA reductase inhibitors (statins) in people with moderate chronic kidney disease (CKD). The objective of this analysis was to determine whether pravastatin reduced the incidence of cardiovascular events in people with or at high risk for coronary disease and with concomitant moderate CKD. Methods and Results - We analyzed data from the Pravastatin Pooling Project (PPP), a subject-level database combining results from 3 randomized trials of pravastatin ( 40 mg daily) versus placebo. Of 19 700 subjects, 4491 ( 22.8%) had moderate CKD, defined by an estimated glomerular filtration rate of 30 to 59.99 mL/min per 1.73 m(2) body surface area. The primary outcome was time to myocardial infarction, coronary death, or percutaneous/surgical coronary revascularization. Moderate CKD was independently associated with an increased risk of the primary outcome ( adjusted HR 1.26, 95% CI 1.07 to 1.49) compared with those with normal renal function. Among the 4491 subjects with moderate CKD, pravastatin significantly reduced the incidence of the primary outcome ( HR 0.77, 95% CI 0.68 to 0.86), similar to the effect of pravastatin on the primary outcome in subjects with normal kidney function ( HR 0.78, 95% CI 0.65 to 0.94). Pravastatin also appeared to reduce the total mortality rate in those with moderate CKD ( adjusted HR 0.86, 95% CI 0.74 to 1.00, P = 0.045). Conclusions - Pravastatin reduces cardiovascular event rates in people with or at risk for coronary disease and concomitant moderate CKD, many of whom have serum creatinine levels within the normal range. Given the high risk associated with CKD, the absolute benefit that resulted from use of pravastatin was greater than in those with normal renal function.

Determinants of subclinical diabetic heart disease

Aims/hypothesis: Subclinical left ventricular (LV) dysfunction has been shown by tissue Doppler and strain imaging in diabetic patients in the absence of coronary disease or LV hypertrophy, but the prevalence and aetiology of this finding remain unclear. This study sought to identify the prevalence and the determinants of subclinical diabetic heart disease. Methods: A group of 219 unselected patients with type 2 diabetes without known cardiac disease underwent resting and stress echocardiography. After exclusion of coronary artery disease or LV hypertrophy, the remaining 120 patients ( age 57 +/- 10 years, 73 male) were studied with tissue Doppler imaging. Peak systolic strain of each wall and systolic (Sm) and diastolic ( Em) velocity of each basal segment were measured from the three apical views and averaged for each patient. Significant subclinical LV dysfunction was identified according to Sm and Em normal ranges adjusted by age and sex. Strain and Em were correlated with clinical, therapeutic, echocardiographic and biochemical variables, and significant independent associations were sought using a multiple linear regressionmodel. Results: Significant subclinical LV dysfunction was present in 27% diabetic patients. Myocardial systolic dysfunction by peak strain was independently associated with glycosylated haemoglobin level ( p< 0.001) and lack of angiotensin- converting enzyme inhibitor treatment ( p= 0.003). Myocardial diastolic function ( Em) was independently predicted by age ( p= 0.013), hypertension ( p= 0.001), insulin ( p= 0.008) and metformin ( p= 0.01) treatment. Conclusions/ interpretation: In patients with diabetes mellitus, subclinical LV dysfunction is common and associated with poor diabetic control, advancing age, hypertension and metformin treatment; ACE inhibitor and insulin therapies appear to be protective.

Optimisation of strain rate imaging for application to stress echocardiography

We sought to improve the feasibility of strain rate imaging (SRI) during dobutamine stress echocardiography (DSE) in 56 subjects at low risk of coronary disease. The impact of several SRI changes during acquisition were studied, including: (1) changing from fundamental to harmonic imaging; (2) parallel beam-forming; (3) alteration of spatial resolution and (4) narrow sector acquisition. We assessed SR signal quality, a quantitative measure of signal noise and measurements of SRI. Of 1462 segments evaluated, 6% were uninterpretable at rest and 8% at peak stress. Signal quality was optimised by increasing temporal (p = 0.01) and spatial resolution (p<0.0001 vs. baseline imaging) at rest and peak. Increasing spatial resolution also minimised signal noise (p<0.0001). Inter-observer variability of time to peak SR and peak SR were less with high temporal and spatial resolution. SRI quality can be improved with harmonic imaging and higher temporal resolution but optimisation of spatial resolution is critical. (C) 2004 World Federation for Ultrasound in Medicine Biology.

Impact of gender on risk stratification by exercise and dobutamine stress echocardiography: long-term mortality in 4234 women and 6898 men

Aims Prior research is limited with regard to the diagnostic and prognostic accuracy of commonplace cardiac imaging modalities in women. The aim of this study was to examine 5-year mortality in 4234 women and 6898 men undergoing exercise or dobutamine stress echocardiography at three hospitals. Methods and results Univariable and multivariable Cox proportional hazards models were used to estimate time to cardiac death in this multi-centre, observational registry. Of the 11 132 patients, women had a greater frequency of cardiac risk factors (P < 0.0001). However, men more often had a history of coronary disease including a greater frequency of echocardiographic wall motion abnormalities (P < 0.0001). During 5 years of follow-up, 103 women and 226 men died from ischaernic heart disease (P < 0.0001). Echocardiographic estimates of left ventricular function (P < 0.0001) and the extent of ischaernic watt motion abnormalities (P < 0.0001) were highly predictive of cardiac death. Risk-adjusted 5-year survival was 99.4, 97.6, and 95% for exercising women with no, single, and multi-vessel ischaemia (P < 0.0001). For women undergoing dobutamine stress, 5-year survival was 95, 89, and 86.6% for those with 0, 1, and 2-3 vessel ischaemia (P < 0.0001). Exercising men had a 2.0-fold higher risk at every level of worsening ischaemia (P < 0.0001). Significantly worsening cardiac survival was noted for the 1568 men undergoing dobutamine stress echocardiography (P < 0.0001); no ischaemia was associated with 92% 5-year survival as compared with death rates of &GE; 16% for men with ischaemia on dobutamine stress echocardiography (P < 0.0001). Conclusion Echocardiographic measures of inducible wall motion abnormalities and global and regional left ventricutar function are highly predictive of long-term outcome for women and men alike.