Best of heart failure
11 been hospitalized with heart failure in the past 12 months. Ivabradine significantly reduced the relative risk of hospital- ization for worsening HF or CV death (RRR 18%, p < 0.0001); the significance is driven mostly by a reduction of rehospitalization. HFNEF describes a heterogeneous pool of patients that make about 50% of HF patients with a unique set of patho- physiologic mechanisms. These patients are typically older with hypertension, obesity, renal failure, anemia, and atrial fibrillation and are more likely to be females. There is also a high incidence of diabetes and coronary artery disease in these patients [ 7 ]. In contrast to patients with impaired left ventricular EF, HFNEF patients have non-dilated left ven- tricular cavity size, concentric instead of eccentric left ven- tricular hypertrophy, and a normal EF [ 34 ]. It is controversial whether LV systolic function is truly normal in patients with HFNEF because EF is an imprecise measure of left ventricular systolic function. However, inva- sive conductance studies suggested from pressure–volume loops that end-systolic pressure–volume relationship is steeper or normal in HFNEF suggesting a normal systolic function. On the other hand, end-diastolic pressure–volume relationship is shifted leftward and upward indicating dia- stolic dysfunction [ 35 , 36 ]. Diastolic dysfunction is not uncommon among elderly patients estimated at about 5.6%, but only 1% has HFNEF [ 37 ]. In one study, the product of left ventricular mass index and left atrial volume has the highest predictive accuracy for HFNEF [ 38 ]. In addition to ventricular stiffness, arterial stiffness has also been suggested to contribute to HFNEF, and the combined ventricular–arterial stiffness leads to an exaggerated hypertensive response after small increases in LV end-diastolic volume [ 7 ]. 24.3 ACC/AHA Classification of Congestive Heart Failure The current ACC/AHA classification for CHF [ 3 ] is comple- mentary to the New York Heart Classification (NYHC) [ 39 ] and helps define the evolution of symptoms of patients with CHF. In addition, the ACC/AHA classification focuses on the risk factors for CHF by identifying patients who have risk factors for CHF. This classification includes four stages of CHF: Stage A: Asymptomatic patients with no left ventricular dys- function but are at risk of developing CHF including patients with coronary artery disease, hypertension, dia- betes mellitus, family history of cardiomyopathy, and the metabolic syndrome. Stage A is not represented in the NYHC. Stage B : Asymptomatic patients with left ventricular dys- function. This is equivalent to Class I of the NYHC. Stage C : Symptom ventricular dysf Class II and Clas ple in the United Stage D : Symptom Class IV of the in the United Sta 24.4 Pharma Heart Fa 24.4.1 Heart Fai Fraction Dysfunct As noted above, o nisms of HFNEF is with diastolic dysf patients with HF a HFNEF. “True” H nary artery disease, strictive cardiomyo and right-sided fail mia, thyrotoxicosis carditis, or intracar Diastolic dysfun ditions including cor lar disease, age [ 4 secondary to intrace [ 42 ], and hypertrop ARB (losartan) has but did not change l Isolated diastolic identified in 11.5% ease with the use o atrial size and N-t (NT-proBNP) appe function [ 45 ]. Also, are seen with differe Recently an algo posed by the work Cardiology [ 47 ]. In toms of HF, normal with evidence of a distensibility, and d of HFNEF if one of PCWP > 12 mmHg ing, E/E ′ > 15 by ti DopplerwithaBNP mL or BNP > 200 and LVH or atrial mal pulmonary ven 24 Evidence-Based Management of the Patient with Congestive Heart Failure 451 been hospitalized with heart failure in the past 12 months. Ivabradine significantly reduced the relative risk of hospital- ization for worsening HF or CV death (RRR 18%, p < 0.0001); the significance is driven mostly by a reduction of rehospitalization. HFNEF describes a heterogeneous pool of patients that make about 50% of HF patients with a unique set of atho- physiologic mechanisms. These patients are typically older with hypertension, obesity, renal failure, anemia, and atrial fibrillation and are more likely to be females. There is also a high incidence of diabetes and coronary artery disease in these patients [ 7 ]. In contrast to patients with impaired left ventricular EF, HFNEF patients have non-dilated left ven- tricular cavity size, concentric instead of eccentric left ven- tricular hypertrophy, and a normal EF [ 34 ]. It is controversial whether LV systolic function is t uly normal in patients with HFNEF because EF is an impr cise measure of left ventricular systolic function. However, inva- sive conductance studies suggested from pressure–v lume loops that end-systolic pressure–volume relationship is steeper or normal in HFNEF suggesting a normal systolic function. On the other hand, end-diastolic pressure–volume relationship is shifted leftward and upward indicating dia- stolic dysfunction [ 35 , 36 ]. Diastolic dysfunction is not uncommon among elderly patients estimated at about 5.6%, but only 1% has HFNEF [ 37 ]. In one study, the product of left ventricular mass index and left atrial volume has the highest predictive accuracy for HFNEF [ 38 ]. In addition to ventricular stiffness, arterial stiffness has also been suggested to contribute to HFNEF, and the combined ventricular–arterial stiffness leads to an exaggerated hypertensive response after small increases in LV end-diastolic volume [ 7 ]. 24.3 ACC/AHA Classification of Congestive Heart Failure The current ACC/AHA classification for CHF [ 3 ] is co ple- mentary to the New York Heart Classification (NYHC) [ 39 ] and helps define the evolution of symptoms of patients with CHF. In addition, the ACC/AHA classification focuses on the risk factors for CHF by identifying patients who have risk factors for CHF. This classification includes four stages of CHF: Stage A: Asymptomatic patients with no left ventricular dys- function but are at risk of developing CHF including patients with coronary artery disease, hypertension, dia- betes mellitus, family history of cardiomyopathy, and the metabolic syndrome. Stage A is not represented in the NYHC. Stage B : Asymptomatic patients with left ventricular dys- function. This is equivalent to Class I of the NYHC. Sta e C : Symptomatic pati nts with exerti n and with l ft ventricular dysfunction. This is equivalent to the NYHC Clas II and Class III and includes about five million peo- ple n the United States. Stage D : Symptomatic patients at rest. This is equivalent to Class IV of the NYHC and includ s ab ut 200,000 people in the United States. 24.4 Pharm cologic Therapy of Congestive Heart Failure 24.4.1 Heart Failure with Normal Ejection Fraction (HFNEF) and Diastolic Dysfunction As not d above, one of the main pathophysiologic mecha- nisms of HFNEF is diastolic dysfunction, but not all patients with diastolic dysfunction have hea t failure, and no all patients with HF and iastolic dysfunction represent “true” HFNEF. “Tru ” HFNEF oes not include those with coro- nary artery disease, valvular heart disease, restrictive or con- strictive cardiomyopathy, besity, pulmonary hyperte sion and right-sided failure, high-output failure caused by ne- mia, th rotoxic sis or art riovenous fistul , co strictive peri- carditis, or intracardiac shunt. Diastolic dysfunction has been associated with many c - dition including coronary artery d sease, hypertension, valvu- lar dis ase, age [ 40 ], elev ted triglyceride levels possibly secondary to intracellular lipid accumulation [ 41 ], sleep apne [ 42 ], and hyp rtrophic cardiomyopathy. Treatment with an ARB (losartan) has yielded improvement in diastolic function but did not change left ventricular cavity size or mass [ 43 ]. Isolated diastol c dysfuncti n is uncommon and has been identified n 11.5% of patients with no CAD or valvular dis- ease with the use of echocardiography [ 44 ]. Increase in left atrial size and N-terminal p o B-type natriuretic peptide (NT-proBNP) app rs to be predictors of LV diastolic dys- function [ 45 ]. Als , varying degrees of d astolic dysfunction re see with different left ventricular geometric patterns [ 46 ]. Recently an algorithm to diagnose HFNEF has been pro- posed by the working group of the European Society of Cardiology [ 47 ]. In general, patients with signs and sy p- toms of HF, normal EF > 50%, and LVEDVI < 97 mL/m 2 and with evidence of abnormal LV relaxa ion, filling, diastolic distensibility, and diastolic stiff ess will meet the diagnosis of HFNEF if one of the following three criteria is met: mean PCWP > 12 mmHg or LVEDP > 16 mmHg by invasive test- ing, E/E ′ > 15 by tissue Doppler, or 8 < E/E ′ < 15 by tissue Doppl rwithaBNP>200pg/mLand/orNT-proBNP>220pg/ mL or BNP > 200 pg/mL and/or NT-proBNP > 220 pg/mL and LVH or atri l fibrillation or left atrial dilation or abnor- mal pulmonary venous return. 24 Evidence-Based Management of the Patient with Congestive Heart Failure
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