Notes from NEJM Review Article: Redfield MM. (2016), Heart Failure with Preserved Ejection Fraction
Case: 73 yo woman seen for hospital f/u after admission for AF with RVR and pulm edema. She c/o fatigue and DOE. Cr 1.4, eGFR 37, NT-proBNP 300. Echo EF 70% with nl LV dimensions. Elevated LA pressure and pulm arterial systolic pressure approx 52.
THE CLINICAL PROBLEM:
- HF is about 50/50% – pEF vs rEF
- Observationally, pEF have about the same prognosis as rEF, but in studies, pEF do better.
- Non-cardiac deaths more common in pEF patients vs rEF.
- The main problem: left ventricular diastolic dysfunction, either baseline or induced by demand or rate. EF does not increase as expected with stress.
- Poor adaptability to load –> rapid pulmonary edema with increased load, rapid hypotension with decreased load.
- Pathophysiology: hypertension-induced remodeling (classic model), endothelial dysfunction –> myocardial inflammation/fibrosis, myocyte signaling derangement, etc. (new model)
DIAGNOSIS AND EVALUATION
- Risk factors for heart failure:
- >60 yr of age
- Proinflammatory coexisting conditions
- Previous hospitalization for heart failure
- DDx considerations:
- cardiac ischemia due to epicardial coronary disease
- lung disease
- pulmonary arterial hypertension that is unrelated to heart failure
- hypertrophic or infiltrative cardiomyopathy
- pericardial disease
- uncorrected primary valve disease
- can be very tough to differentiate DOE from HF vs DOE from non-cardiac causes or deconditioning!
- Labs and Imaging:
- In the outpatient setting, HF is less likely if BNP < 35 or NT-proBNP < 125 than in patients with higher levels
- BUT…these can be normal in obese patients or in patients with only exertional sxs! Normal in up to 30% of HFpEF patients. Also, BNPs can be up in the elderly or those with AFib without HF.
- EKG: LVH, LAE or AFib.
- CXR: Cardiomegaly, pulmonary venous hypertension, interstitial or alveolar edema, pleural effusion
- Echo (Doppler): cardiac remodeling, elevated LA pressure, abnormal relaxation, PA systolic > 35, RV enlargement or systolic dysfunction (25-30%, often also with AFib).
- Echo evidence of diastolic dysfcn can be absent in well-treated patients, or in those with only exertional symptoms!
SPECIALIZED TESTING IN SELECTED PATIENTS
- Stress testing, angiography or both: pts with CAD risk factors, if candidate for antiischemic therapy or revascularization.
- Stress testing can tell you about chronotropic insufficiency and exaggerated hypertensive response, as well as deconditioning, poor pulmonary function.
- Pulm artery cath for patients to clarify severity of pulmonary hypertension if PA pressures on Doppler > 50.
- Markedly elevated PA wedge pressures –> L atrial stiffness, hallmark of condition.
- Cardiac MRI if infiltrative or inflammatory cardiomyopathy suspected (e.g., amyloidosis, sarcoidosis, respectively).
- Cardiac scintigraphy with specific tracers: identify cardiac amyloidosis.
- Consider renal artery stenosis in those with risk factors or repeated episodes of HFpEF.
- If Cr not bad, but pt requiring high-dose diuretics, consider occult renal failure with alternative markers of eGFR (e.g., check cystatin C).
- Goals: relieve volume overload, treat co-existing conditions, increase exercise tolerance, manage chronic disease while decreasing hospitalizations. No tx has improved outcomes overall.
ANTIHYPERTENSIVES AND SPIRONOLACTONE
- ACEI/ARBs: no improved outcomes
- Spironolactone: no improved outcome, and more hyperkalemia and renal dysfunction
- Beta-blockers: conflicting data, no clear patient-oriented benefit
- So…use ACEI/ARB and B-blockers only when other reasons exist to use them! (e.g, CRF for ACEI/ARB)
- Diuretics for volume overload: Giving thiazide (eg, metazolone) prior to loop diuretic (furosemide) may work better in pts requiring high-dose loop diuretics.
- Some requiring high-dose diuretics may require IV loop diuretics
- Diuretic tx is obviously risky: monitor closely for hypoK, hypoNa, ARF
- Avoid fluctuations in Na intake, and low-Na diet MAY help (unclear), but high-Na diet definitely does not.
- Hypertension: In general, follow JNC-8. There may be some benefit to lower targets, but trials did not include HF patients, so uncertain.
- HTN + CKD: Give an ACEI/ARB.
- HTN: thiazide + CCB + ACEI/ARB for non-blacks; thiazide + CCB for blacks
- Statins: Use according to usual guidelines.
- CAD: follow usual guidelines. Select pts may benefit from revascularization for angina/ischemia.
- AFib: follow usual guidelines. Rate > rhythm control.
- Obesity: lose weight.
- OSA and lung disease: treat aggressively.
- Nitrates like isosorbide mononitrate: meh. No clear benefit in clinical outcomes.
- Cardiac rehab: may help, but insurers don’t cover it in HFpEF pts (but do for HFrEF).
- Education: self-monitoring! (Weight, salt intake, symptoms, med compliance, etc.)
AREAS OF UNCERTAINTY:
- Clinical trials of sacubitril-valsartan ongoing.
- ??? do defibrillators help
- ??? how best to optimally manage co-morbid conditions