Pierluigi Costanzo

Do changes of 6-minute walk distance predict clinical events in patients with pulmonary arterial hypertension? A meta-analysis of 22 randomized trials.

OBJECTIVES The objectives of this study were to verify whether improvement in 6-min walk distance (6MWD) is associated with clinical outcome in pulmonary arterial hypertension (PAH). BACKGROUND 6MWD is used as an endpoint to assess the benefit of therapies in PAH. However, whether changes in 6MWD correlate with clinical outcome is unknown. METHODS Randomized trials assessing 6MWD in patients with PAH and reporting clinical endpoints were included in a meta-analysis. The meta-analysis was performed to assess the influence of treatment on outcomes. Meta-regression analysis was performed to test the relationship between 6MWD changes and outcomes. RESULTS Twenty-two trials enrolling 3,112 participants were included. Active treatments led to significant reduction of all-cause death (odds ratio [OR]: 0.429; 95% confidence interval [CI]: 0.277 to 0.664; p < 0.01), hospitalization for PAH, and/or lung or heart-lung transplantation (OR: 0.442; 95% CI: 0.309 to 0.632; p < 0.01), initiation of PAH rescue therapy (OR: 0.555; 95% CI: 0.347 to 0.889; p = 0.01), and composite outcome (OR: 0.400; 95% CI: 0.313 to 0.510; p < 0.01). No relationship between 6MWD changes and outcomes was detected. CONCLUSIONS In patients with PAH, improvement in 6MWD does not reflect benefit in clinical outcomes.

Impact of gender in primary prevention of coronary heart disease with statin therapy: A meta-analysis

BACKGROUND Evidence of lipid-lowering from clinical trials that included women is adequate to support their use in secondary prevention in women with known coronary disease. However the role of statin therapy in primary prevention is still controversial, in particular for female gender. The aim of our study is to perform a meta-analysis comparing by gender the cardiovascular outcomes related to statin therapy in primary prevention. METHODS We performed a meta-analysis including 8 randomized controlled trials (19,052 and 30,194 men, mean follow-up 3.9 years) that assessed the cardiovascular outcomes related to statin therapy, including studies that provided sex-specific results. MEDLINE and the Cochrane Database, were searched for articles published in English and other languages up to March 2008. RESULTS Statins do not appear to have a beneficial effect on total mortality for both men and women in primary prevention over the 2.8- to 5.3 year study period (men: 95% Confidence Interval (CI) 0.83-1.04; comparison p = 0.22; women: 0.96; CI 0.81-1.13; p = 0.61). Statin therapy reduced the risk of coronary heart disease (CHD) events in men (0.59; CI 0.48-0.74; p = 0.0001), however in women this risk reduction was weakly significant (0.89 CI 0.79-1.00; p = 0.05) and disappeared when in sensitivity analysis, trials not entirely of primary prevention were excluded (HPS, PROSPER) (0.95 CI 0.78-1.16; comparison p = 0.562). CONCLUSIONS Our study showed that statin therapy reduced the risk of CHD events in men without prior cardiovascular disease, but not in women. Statins did not reduce the risk of total mortality both in men and women.

A meta-analysis reporting effects of angiotensin-converting enzyme inhibitors and angiotensin receptor blockers in patients without heart failure.

OBJECTIVES The goal of the study was to assess the effects of angiotensin-converting enzyme inhibitors (ACE-Is) and angiotensin receptor blockers (ARBs) on the composite of cardiovascular (CV) death, myocardial infarction (MI), and stroke, and on all-cause death, new-onset heart failure (HF), and new-onset diabetes mellitus (DM) in high-risk patients without HF. BACKGROUND ACE-Is reduce CV events in high-risk patients without HF whereas the effects of ARBs are less certain. METHODS Twenty-six randomized trials comparing ARBs or ACE-Is versus placebo in 108,212 patients without HF were collected in a meta-analysis and analyzed for the risk of the composite outcome, all-cause death, new-onset HF, and new-onset DM. RESULTS ACE-Is significantly reduced the risk of the composite outcome (odds ratio [OR]: 0.830 [95% confidence interval (CI): 0.744 to 0.927]; p = 0.001), MI (OR: 0.811 [95% CI: 0.748 to 0.879]; p < 0.001), stroke (OR: 0.796 [95% CI: 0.682 to 0.928]; p < 0.004), all-cause death (OR: 0.908 [95% CI: 0.845 to 0.975]; p = 0.008), new-onset HF (OR: 0.789 [95% CI: 0.686 to 0.908]; p = 0.001), and new-onset DM (OR: 0.851 [95% CI: 0.749 to 0.965]; p < 0.012). ARBs significantly reduced the risk of the composite outcome (OR: 0.920 [95% CI: 0.869 to 0.975], p = 0.005), stroke (OR: 0.900 [95% CI: 0.830 to 0.977], p = 0.011), and new-onset DM (OR: 0.855 [95% CI: 0.798 to 0.915]; p < 0.001). CONCLUSIONS In patients at high CV risk without HF, ACE-Is and ARBs reduced the risk of the composite outcome of CV death, MI, and stroke. ACE-Is also reduced the risk of all-cause death, new-onset HF, and new-onset DM. Thus, ARBs represent a valuable option to reduce CV mortality and morbidity in patients in whom ACE-Is cannot be used.

Calcium channel blockers and cardiovascular outcomes: a meta-analysis of 175 634 patients

Objective The aim of this study was to assess the effect of calcium channel blocker (CCB) treatment, compared with other drugs or placebo/top of therapy, on all-cause mortality, cardiovascular death, major cardiovascular events, heart failure, myocardial infarction and stroke. Methods We performed a meta-analysis of randomized controlled trials that compared a long-acting calcium channel blocker with another drug or placebo/top of therapy and that assessed all-cause mortality and cardiovascular events. Results We included 27 trials (175 634 patients). The risk of all-cause death was reduced by dihydropyridine CCBs [odds ratio (OR) 0.96; 95% confidence interval (CI) 0.93–0.99; comparison P = 0.026; heterogeneity P = 0.87)] without influence of placebo trials. The risk of heart failure was increased by CCBs compared with active treatment (OR 1.17; 95% CI 1.11–1.24; comparison P = 0.0001; heterogeneity P = 0.0001), and it was decreased when compared with placebo (OR 0.72; 95% CI 0.59–0.87; comparison P = 0.001; heterogeneity P = 0.77), also in the subgroup of coronary artery disease patients (OR 0.76; 95% CI 0.61–0.95; comparison P = 0.01; heterogeneity P = 0.29). CCBs did not increase the risk of myocardial infarction (OR 1; 95% CI 0.95–1.04; comparison P = 0.83, heterogeneity P = 0.004), cardiovascular death (OR 0.97; 95% CI 0.93–1.02; comparison P = 0.24; heterogeneity P = 0.16), major cardiovascular events (OR 0.97; 95% CI 0.90–1.06; comparison P = 0.53; heterogeneity P = 0.0001). CCBs decreased the risk of fatal or nonfatal stroke (OR 0.86; 95% CI 0.82–0.90; comparison P = 0.0001, heterogeneity P = 0.12), also, when compared with angiotensin-converting enzyme inhibitors (OR 0.87; 95% CI 0.78–0.97; comparison P = 0.016; heterogeneity P = 0.48). Conclusion Our study demonstrates that CCBs reduce the risk of all-cause mortality compared with active therapy and prevent heart failure compared with placebo. Furthermore, with the inclusion of recent trials, we confirm that they reduce the risk of stroke, also in comparison to angiotensin-converting enzyme inhibitors and do not increase the risk of cardiovascular death, myocardial infarction and major cardiovascular events.

Prognostic role of myocardial single photon emission computed tomography in the elderly

The increase in average life expectancy will move the burden of coronary artery disease (CAD) to older patients. Myocardial perfusion imaging by single photon emission computed tomography (SPECT) has been extensively validated for diagnosis and prognostic evaluation in large population series. Yet, its use is usually limited in elderly patients in whom, despite increased absolute cardiovascular risk, diagnostic and therapeutic work-up is often underperformed. American College of Cardiology/American Heart Association guidelines recommend exercise ECG testing as the initial noninvasive method for assessment of CAD in patients with a normal or near-normal resting ECG, regardless of age. However, a considerable proportion of elderly patients is unable to reach an adequate workload during the exercise test and the majority of those undergoing for standard exercise treadmill score are classified as intermediate risk. In elderly patients, SPECT imaging may provide valuable diagnostic and prognostic information for clinical management. In particular, normal or near normal SPECT identifies elderly patients at low risk of major adverse cardiac events at the short-term follow-up.

Left ventricular hypertrophy reduction and clinical events. A meta-regression analysis of 14 studies in 12,809 hypertensive patients

BACKGROUND Left ventricular hypertrophy (LVH) is an independent risk factor for clinical events (CE), and regression of LVH is associated with reduction of cardiovascular risk. However, whether a continuous relationship between reduction of LVH and risk of CE exists has not been investigated. METHODS Randomized clinical trials evaluating LVH at baseline and reporting quantitative LVH changes and CE, stroke or new onset heart failure) were included. Meta-regression analysis was performed to test the relationship between changes in LVH and incidence of the composite outcome (all-cause death, MI, stroke or new onset heart failure) and between changes of LVH and occurrence of each component of the composite outcome. Analysis of potential confounder variables was also performed. RESULTS Fourteen trials including 12,809 participants and reporting 2259 events were included. Follow-up ranged from 0.50 to 5 years, with mean 1.97 ± 1.50 years. Mean age was 62 ± 5 years and 52% of patients were women. The composite outcome was significantly reduced by active treatments (OR: 0.851, IC: 0.780 to 0.929, p<0.001), as well stroke (OR: 0.756, IC: 0.638 to 0.895, p<0.001) whereas MI and new onset heart failure were not significantly reduced by treatments. LVH changes did not predict the reduction of CE. No significant influence on the association of baseline patients and studies characteristics was found. CONCLUSIONS A significant continuous relationship between LVH changes and CE could not be demonstrated in hypertensive patients, independently on the technique or drug used. Ad hoc designed studies should further explore the relationship between LVH modification and outcomes in hypertensive patients.

Molecular imaging of atherosclerosis in translational medicine

Functional characterization of atherosclerosis is a promising application of molecular imaging. Radionuclide-based techniques for molecular imaging in the large arteries (e.g. aorta and carotids), along with ultrasound and magnetic resonance imaging (MRI), have been studied both experimentally and in clinical studies. Technical factors including cardiac and respiratory motion, low spatial resolution and partial volume effects mean that noninvasive molecular imaging of atherosclerosis in the coronary arteries is not ready for prime time. Positron emission tomography imaging with fluorodeoxyglucose can measure vascular inflammation in the large arteries with high reproducibility, and signal change in response to anti-inflammatory therapy has been described. MRI has proven of value for quantifying carotid artery inflammation when iron oxide nanoparticles are used as a contrast agent. Macrophage accumulation of the iron particles allows regression of inflammation to be measured with drug therapy. Similarly, contrast-enhanced ultrasound imaging is also being evaluated for functional characterization of atherosclerotic plaques. For all of these techniques, however, large-scale clinical trials are mandatory to define the prognostic importance of the imaging signals in terms of risk of future vascular events.

Noninvasive assessment of coronary anatomy and myocardial perfusion: going toward an integrated imaging approach.

Many noninvasive imaging techniques are available for the evaluation of patients with known or suspected chronic coronary artery disease. Among these, computed tomography-based techniques allow the quantification of coronary atherosclerotic calcium and noninvasive imaging of coronary arteries, whereas nuclear cardiology is the most widely used noninvasive approach for the assessment of myocardial perfusion. The available single-photon emission computed tomography flow agents are characterized by a cardiac uptake proportional to myocardial blood flow. In addition, different positron emission tomography tracers may be used for the quantitative measurement of myocardial blood flow and coronary flow reserve. Extensive research is currently being performed in the development of noninvasive coronary angiography and myocardial perfusion imaging using cardiac magnetic resonance. Finally, new multimodality imaging systems have been recently developed, bringing together anatomical and functional information. This review sought to provide a description of the relative merits of noninvasive imaging techniques in the assessment of coronary anatomy and myocardial perfusion in patients with known or suspected coronary artery disease.

Questioning the predictive role of carotid intima–media thickness

Interest in carotid intima-media thickness (IMT), as a tool to evaluate cardiovascular risk has been driven by studies that demonstrate a relationship between carotid IMT and the incidence of cardiovascular events. However, no study was designed and powered to demonstrate a relationship between changes in carotid IMT during follow-up and cardiovascular events. Therefore, a pooled analysis of existing clinical studies was performed to investigate this relationship. This analysis failed to demonstrate a predictive role of changes in carotid IMT for cardiovascular events. The reason for the lack of clear evidence for a predictive role for changes in IMT are uncertain but may reflect methodological problems related to intra- and inter-observer variability, as it seems unlikely that progression of carotid atherosclerosis would not predict outcome. A further meta-analysis based on individual patient-data has been planned, that may better address this issue. The variability of ultrasound measurements of carotid IMT are likely to be reduced by further development of automatic calculation of this index by MRI.

Use of Carotid Intima-Media Thickness Regression to Guide Therapy and Management of Cardiac Risks

Opinion statementAlthough carotid intima-media thickness (IMT) has been broadly used as a tool to evaluate cardiovascular risk, its role as a surrogate endpoint is still debated. The main issue is the fact that no study has ever been powered to show a relationship between changes in carotid IMT during follow-up and cardiovascular events. A meta-analysis of existing clinical studies was performed to investigate this relationship but it failed to demonstrate a predictive role of regression in carotid IMT for cardiovascular events. The reasons for the lack of a clear evidence for a predictive role of IMT progression are unknown but are likely multifactorial. Firstly, it may depend on the fact that this index is not a pure atherosclerosis index. Second, carotid atherosclerosis does not always reflect coronary atherosclerosis. Furthermore, methodologic problems related to intra- and interobserver variability make this index not adequately reproducible when tracking the progression of carotid atherosclerosis. A further meta-analysis based on individual patient data, instead of published data, has been planned to better address the predictive role of IMT. Lastly, in the future, the variability of ultrasound measurements of carotid IMT are likely to be reduced by further development of automatic calculation of this index by magnetic resonance imaging.