Risk stratification of patients with

Heeschen C, Hamm CW, MhrovicV etal. N-terminal pro-B-type natriuretic peptide levels for dynamic risk stratification of patients with acute coronary syndromes. Circulation 2004 ... 

Results from several studies support the monitoring BNP or NT proBNP for the risk stratification of patients with CHF, with or without a previous history. This involves patients presenting with a wide range of clinical pathologies, including (-g 63,io6,i72,i9o noHcardiac pathologies... 

Jernberg T, Stridsberg M, Venge P, Lindahl B. N-terminal pro brain natriuretic peptide on admission for early risk stratification of patients with chest pain and no ST-segment elevation. J Am Coll Cardiol 2002 40 437-45. 

Konstantinides S, Geibel A, Olschewski M, Kasper W, Hruska N, Jackie S, et al. Importance of cardiac troponins I and T in risk stratification of patients with acute pulmonary embohsm. Circulation 2002 106 1263-8. 

The presence of different ECG patterns plays a decisive role in the risk stratification of patients with NSTE-ACS. Table 8.1 shows the different ECG patterns found in STE-ACS and NSTE-ACS. We will just highlight here that in case of NSTE-ACS the prognosis is worse when the patient evolves towards a non-Q-wave infarction and even more so when it ends up as a Q-wave infarction. Factors, such as age, the presence of refractory angina and previous infarctions, ejection fraction, enzymatic level,... 

Holper EM, Antman EM, McCabe CH et al. A simple, readily available method for risk stratification of patient with unstable angina and non-ST elevation myocardial infarction. Am J Cardiol 2001 87 1008. 

Wong CK, Gao W, Stewart RA et al. Hirulog Early Reperfusion Occlusion (HERO-2) Investigators. Risk stratification of patients with acute anterior myocardial infarction and right bundle-branch block importance of QRS duration and early ST-segment resolution after fibrinolytic therapy. Circulation 2006b 114(8) 783. 

M. J. Tanasijevic, C. P. Canon, and E. M. Antman The role of cardiac troponin-I (CTnl) in risk stratification of patients with unstable coronary artery disease. Clinical Cardiology 22, 11 (1999). 

Risk stratification of patients with nonischemic cardiomyopathy has proven to be more challenging than in their counterparts with CAD. The Defibrillators in Non-Ischemic Cardiomyopathy Treatment Evaluation... 

To date, the most promising role of TWA appears to be in the risk stratification of patients with ischemic cardiomyopathy with a moderately reduced LVEF, especially in conjunction with another marker of risk stratification such as the EP study, as demonstrated in the ABCD trial. TWA is mainly useful for its high NPV in this population, as it is in patients with nonischemic cardiomopathy and in patients with a relatively preserved LVEF soon after a MI. Its NPV does not appear to be sufficient to withhold ICD placement in higher risk (lower LVEF) patients, and its PPV value is not sufficient in any of the studied populations to recommend ICD implantation, even when combined with other risk markers. 

Table 2.1 American College of Cardiology/American Heart Association system for risk stratification of patients with non-ST-elevation acute coronary syndromes... 

The Controversy 167 Risk Stratification of Patients With Asymptomatic CAS 168 Carotid Artrey Stenting for Asymptomatic Carotid Artery Disease 170 Summary 174 References 176... 

Most experts agree that certain patients with asymptomatic CAS are at high risk for stroke and may derive significant benefit from carotid revascularization. Identification of those patients, however, has been elusive in clinical trials. Risk stratification of patients with asymptomatic CAS is particularly important among patients with 60% to 79% stenosis, in whom the appropriate management is more uncertain. Identifying high-risk patients will certainly lead to better resource utilization for both medical and revascularization therapies for patients with asymptomatic CAS. 

The troponins have been used successfully in the diagnosis of Ml and in the risk stratification of patients with unstable angina. 

Dinckal, M.H., et al., QT dispersion in the risk stratification of patients with unstable angina correlation with clinical course, troponin T and scintigraphy. Acta Cardiol, 2004. 59(3) p. 283-9. 

Chamuleau SA, Meuwissen M et al. (2002) Usefulness of fractional flow reserve for risk stratification of patients with multivessel coronary artery disease and an intermediate stenosis. Am J Cardiol 89 377-380... 

Serum biomarkers of acute coronary syndrome play a critical role in the diagnosis and risk stratification of patients with ACS. Myocardial necrosis observed in patients with ACS releases a variety of proteins into blood that can be used as biomarkers. Antiquated markers include aspartate aminotransferase, lactate dehydrogenase (LD) and its isoenzyme (LDl), myoglobin, and creatine kinase (CK) and its isoenzyme (CK-MB). While some of these markers are still in routine use, there is consensus among experts in the field of cardiology, emergency medicine, and laboratory medicine that cardiac troponin is the gold standard marker for ACS. 

Troponin has emerged as the biomarker of choice for diagnosis and risk stratification of patients with ACS. Optimum use of this biomarker requires improvements in the performance of analytical measurements made from the central laboratory, especially from POCT platforms. To meet the current and future chnical needs, troponin assays must be faster, more analytically sensitive, and more convenient from a standpoint of information transfer. This requires development of novel delivery and detection schemes, and approaches towards data connectivity. This real-world problem illustrates the need for cooperation between clinical laboratory science, biomedical engineering, and informational science. 

Baroreflex sensitivity (BRS) is a measure of the reflex bradycardia that follows an increase in systemic blood pressure. This reflex is mediated by arterial baroreceptors and may be measured after injection of phenylephrine or after spontaneous rises in blood pressure (64). Correlation between the two different tests is poor (69) and measures of baroreflex sensitivity are only moderately reproducible (70). Data on the ability of BRS to predict sudden death are conflicting. In the ATRAMI study in 1284 patients post-MI, HRV, and BRS were assessed at discharge (71). Depressed HRV and BRS carried a significant risk of cardiac mortality when both parameters were depressed the risk increased further. Thus, ATRAMI demonstrated that since BRS adds to the prognostic value of HRV, the two measures are complimentary rather than redundant. However, in another study of 700 post-MI patients, HRV or BRS was not predictive of SCD (60). BRS also does not appear useful for risk stratification in patients with nonischemic cardiomyopathy (63). 

Therefore, in patients post-MI with ischemic cardiomyopathy, NSVT may predict SCD and total mortality however, the incremental risk stratification in patients with LVEF <35% is unclear. The utility of obtaining routine Holter monitors for screening in this population is unclear and not currently recommended (77). NSVT may be more useful in patients post-MI with LVEF over the range of 35% to 40% however, it is difficult to separate the predictive ability of NSVT versus EP study in this population. In patients with nonischemic cardiomyopathy, NSVT has not been demonstrated to reliably predict SCD. 

Cameron EA, Pratap JN, Sims TJ, et al. (2002) Three-year prospective validation of a pre-endoscopic risk stratification in patients with acute upper-gastrointestinal haemorrhage. Eur J Gastroenterol Hepatol 14 497-501... 

Risk-stratification of the patient with NSTE ACS is more complex, as in-hospital outcomes for this group of patients varies with reported rates of death of 0% to 12%, reinfarction rates of 0% to 3%, and recurrent severe ischemia rates of 5% to 20%.12 Not all patients presenting with suspected NSTE ACS will even have CAD. Some will eventually be diagnosed with non-ischemic chest discomfort. In general, among NSTE patients, those with ST-segment depression (Fig. 5-1) and/or elevated troponin and/or CK-MB are at higher risk of death or recurrent infarction. 

Numerous prospective and retrospective clinical studies have evaluated and compared the utility of measurements of cTnl and cTnT for risk stratification or clinical outcomes assessment of patients with ACS with possible myocardial... 

Gage BF, van Walraven C, Pearce LA et al. (2004). Selecting patients with atrial fibrillation for anticoagulation. Stroke risk stratification in patients taking aspirin. Circulation 110 2287-2292 Giles MF, Rothwell PM (2007). Risk of stroke early after transient ischaemic attack a systematic review and meta-analysis. Lancet Neurology 6 1063-1072... 

Whether the presence of scar and/or the amount of scar is predictive of SCD is yet to be determined. In a study of 48 patients with CAD who were referred for EP study, infarct size was compared with LVEF, with respect to their correlation with induciblity on EP study (91). They found that patients with sustained, mono-morphic VT had larger infarcts than patients who did not have inducible arrhythmias, and patients with polymorphic VT or VF had intermediate infarct masses. Infarct mass and surface area were better predictors of inducibility of monomorphic VT than LVEF. The study was limited by its small sample size, but demonstrates that scar burden on MRI may correspond to inducibility on EP study. However, while inducibility on EP study is helpful in risk stratification of SCD, as discussed earlier even patients with a negative EP study have a high rate of future SCD. Thus, the true value of delayed enhancement MRI would be to demonstrate risk stratification beyond that of conventional methods. 

FIGURE 2.1 Algorithm for risk stratification and treatment of patients with acute coronary syndromes. (STEMI, ST-elevation myocardial infarction NSTEMI, non-STEMI.)... 

---