1,721,034 research outputs found
Postconditioning
No full textEarly and successful reperfusion is mandatory to limit infarct size, and reduce morbidity and mortality from acute coronary syndrome. However, reperfusion is a double edge sword, with the potential to induce additional damage to the ischemic myocardium (reperfusion injury). The reperfusion injury may account for up to 50% of final infarct size. By stimulating cardioprotective pathway, postconditioning (ischemic, remote and pharmacological postconditioning) can reduce the negative impact of ischemia and reperfusion on the heart. In the present article, we briefly elucidate the mechanisms involved in cardiac protection and discuss the available supporting data for the use of postconditioning in the clinical scenario
Controversies in fractional flow reserve
No full textFractional flow reserve (FFR) has been identified as the optimal diagnostic tool to identify significant coronary lesion. However, current evidence does not support this role. The optimal diagnostic strategy should give highly sensitive and specific results with lowest cost and accomplishing this task has been made more difficult in the era following the COURAGE trial
Persistent angina: the Araba Phoenix of cardiology
No full textAbstract
Percutaneous coronary intervention (PCI) has not been shown to reduce mortality in patients with stable coronary artery disease (CAD). The long-term clinical success of PCI is defined as the persistent relief of signs and symptoms of myocardial ischemia for more than 6 months after the index procedure. Data from large trials investigating the use of PCI in patients with stable CAD show that angina is still experienced in a large number of patients one year after the procedure and that this proportion increases over time. These data are, however, largely from post-hoc analyses of studies powered to measure other end points. We conducted the first prospective study investigating the incidence of persistent angina and inducible ischemia in patients with stable CAD undergoing PCI rated as 'successful' by the interventional cardiologist, and present an interim analysis of data from 220 patients. The mean age of our patients was 65 years; they were mostly male, mildly obese, hypertensive and dyslipidemic. Most patients had single-vessel disease affecting the left anterior descending artery and received a drug-eluting stent, and all patients had a positive stress test before PCI. At the follow-up visit, which was performed within 4 weeks of the index procedure, 52% of patients still had a positive stress test. Before PCI, 66% of patients reported experiencing angina on exertion. At the follow-up visit, one-third of those patients were still experiencing angina. Patients experiencing persistent angina (21% of the study population) graded their symptoms as improved (66%), unchanged (33%) or worsened (1%) after the procedure. We hypothesize that coronary microvascular dysfunction is a possible cause of persistent angina in this highly select group of patients. Risk factors for microvascular dysfunction include dyslipidemia, smoking and diabetes. It is currently difficult to dissect the relative contributions of coronary artery stenosis and microvascular dysfunction in precipitating myocardial ischemia. A better understanding of these mechanisms could reduce the number of unnecessary PCI procedures. Moreover, treatment options in patients who continue to experience angina despite 'optimal' medical therapy and 'successful' PCI are urgently required
Interventional cardiology : Cost-effectiveness of PCI guided by fractional flow reserve
Full text linkCoronary revascularization strategies have been evaluated in numerous clinical trials. As coronary revascularization has become more common, concerns over financial costs have increased
Myocardial protection during PCI in STEMI : strategy reperfusion effects in acute MI patients (stream study)
Full text linkBackground: Numerous strategies have been proposed to preserve cardiac muscle during myocardial infarction. Intracoronary adenosine and
post conditioning has been reported to reduce infarct size in patients with acute MI. Our purpose is to compare these two strategies.
Methods: Consecutive patients undergoing primary percutaneous coronary intervention (PCI) for STEMI within 6 hours after symptom onset were
randomly assigned to the postconditioning, adenosine or controls group. Exclusion criteria were: previous MI, revascularization, controindication
to PCI or cardiogenic shock. Adenosine was administrated in 2 mg bolus with over the wire cathether; postconditioning included 4 sequencies of 1
minute balloon inflation/one minute reperfusion. Primary end point include: wall motion score index (1-6 months), ST resolution 30 minute after the
procedure, cardiac markers (peak values) and infarct related end diastolic wall tickness. 2-way ANOVA is used to identify interaction between the
treatment modality. A P<0.05 will be considered statistically significant.
Results: 46 patients were enrolled. The 3 groups were similar for age, sex, and infarct location. There was no difference between adenosine
administration and postconditioning in terms of primary endpoint. There were statistical significative results among treatments (adenosine
+postconditioning) vs controls. Wall motion score index at 6 months was improved in treated patients (adenosine group 1.15 WMSI mean,
postconditioning group 1.15, controls group 1.89- p<0.05) Treated patients showed reduction in wall tickness (calculate as the percentage
reduction in tickness of the ischemic wall between discharge and six months follow up) (adenosine group 13.0%, postconditioning group 19.2%,
controls group 5.1% p<0.05). Complete ST-segment resolution occurred in 56 % of patients in the adenosine group and in 68 % of patients in
postconditioning group and 27% of patients in the conventional PCI group (P<0.05).
Conclusion: Myocardial protection is feasible and well tolerated and adjunt to primary PCI ameliorat
Trials in ischemic heart disease do not represent the ischemic universe
Full text linkBackground: In clinical trials of revascularization the terms “coronary artery disease” and “ischemic heart disease” are sometimes used
interchangeably. This can create confusion in inclusion and exclusion criteria, which may lead to uncertain results. Our purpose is to investigate
if the clinical trials population comparing percutaneous coronary revascularization to medical therapy for stable ischemic heart disease re!ects
speci"cally concerns patients with demonstrable ischemia and how many patients are included in the trial with the only evidence of coronary
atherosclerosis and without ischemia.
Methods: Individual trials data (number of patients screened, number of patients enrolled, number of patients with positive stress test or without
stress test) were obtained from ACME I, ACME II, RITA I, RITA II, MASS I, MASS II, AVERT, ACIP and COURAGE. Published data were used to calculate the
number of patients included in the trials with negative stress test but signi"cant coronary artery stenosis and the number of patients excluded from
the trials with positive stress test or angina (but without signi"cant coronary artery stenosis at the time of angiography).
Results: More then 195.213 people have been screened from 1998 to 2011. Overall about 30% of patients were excluded if they did not met
the angiographic criteria, even if ischemia was present to the stress test or angina, and almost 20% of patients per trial were included without
demonstrable ischemia.
Conclusion: Clinical trials have contributed to the confusion between coronary artery disease and ischemic heart disease. This may limit the ability
to interpret the results and apply them in practice
Pharmacological Agents Targeting Myocardial Metabolism for the Management of Chronic Stable Angina : an Update
No full textDespite continuous advances in myocardial revascularization procedures and intracoronary devices, patients with ischemic heart disease (IHD) still experience worse prognosis and poor quality of life (QoL). Indeed, chronic stable angina (CSA) is a common disease with a large burden on healthcare costs. Traditionally, CSA is interpreted as episodes of reversible myocardial ischemia related to the presence of stable coronary artery plaque causing myocardial demand/supply mismatch when myocardial oxygen consumption increases. Accordingly, revascularization procedures are performed with the aim to remove the flow limiting stenosis, whereas traditional medical therapy (hemodynamic agents) aims at reducing myocardial oxygen demands. However, although effective, none of these treatment strategies or their combination is either able to confer symptomatic relief in all patients, nor to reduce mortality. Failure to significantly improve QoL and prognosis may be attributed at least in part to this “restrictive” understanding of IHD. Despite for many years myocardial metabolic derangement has been overlooked, recently it has gained increased attention with the development of new pharmacological agents (metabolic modulators) able to influence myocardial substrate selection and utilization thus improving cardiac efficiency. Shifting cardiac metabolism from free fatty acids (FA) towards glucose is a promising approach for the treatment of patients with stable angina, independently of the underling disease (macrovascular and/or microvascular disease). In this sense cardiac metabolic modulators open the way to a “revolutionary” understanding of ischemic heart disease and its common clinical manifestations, where myocardial ischemia is no longer considered as the mere oxygen and metabolites demand/supply unbalance, but as an energetic disorder. Keeping in mind such an alternative approach to the disease, development of new pharmacological agents directed toward multiple metabolic targets is mandatory
Do clinical trials in ischemic heart disease meet the needs of those with ischemia?
No full textDo Clinical Trials In Ischemic Heart Disease Meet the Needs of Those With Ischemia
The second law of thermodynamics and the heart
No full textThe second law of thermodynamics explains the phenomenon of irreversibility and the increasing entropic trend of nature. Similar to human-made machines, living structures are subjected to entropy generation, becoming 'worn' and 'damaged' from use. However, they have the possibility of eluding or deferring these processes. According to nonequilibrium thermodynamics, the heart could be considered as an open dissipative system, since it has the potential to offset the body's increasing entropic burden by using energy to export entropy to the surroundings. By organizing the tissues' molecules in order to perform external work as a result of its ability to provide oxygen and nutrients and remove waste products, the heart maintains the organization of the living structure and acts as an open dissipative system. However, the increase in tissues' randomness and disorder as a result of a number of disease states may be responsible for the intervening cardiac damage and entropy generation. This effect is known as the 'Dorian Gray effect' of the heart. Technical advances, including MRI and 3D echocardiography, may provide a means to improve the understanding of thermodynamic aspects of cardiovascular physiology and heart diseas
Prediction of post percutaneous coronary intervention myocardial ischaemia
No full textFollowing revascularisation the majority of patients obtain symptom relief and improved quality of life. However, myocardial ischaemia may recur or persist in a significant patient subset. Symptom recurrence is usually attributed to inaccurate evaluation of epicardial stenosis, incomplete revascularisation or stent failure and disease progression. However, technological advances with modern imaging and/or physiological evaluation of epicardial plaques have not solved this issue. Conversely, recent clinical studies have shown that abnormal coronary vasomotion and increased myocardial resistance are frequent determinants of post-percutaneous coronary intervention (PCI) myocardial ischaemia. Strategies to enhance prediction of post-PCI angina include proper selection of patients undergoing revascularisation, construction of clinical prediction models, and further invasive evaluation at the time of coronary angiography in those with high likelihood
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