The correct answer is: E. Mixed heart disease (constriction and restrictive cardiomyopathy)

Constrictive pericarditis (CP) and restrictive cardiomyopathy are two important etiologies to consider in the differential diagnosis in patients with symptoms of heart failure with preserved left ventricular ejection fraction. Differentiating between these two can sometimes be difficult but clinically it is very important. This is because constrictive pericarditis is treated surgically with pericardiectomy while restrictive cardiomyopathy requires optimized medical regimen. CMR and cardiac catheterization have an essential role in providing anatomical and pathophysiological data to guide the diagnostic evaluation.¹ However, in our case imaging features of both conditions are present hence the correct answer is mixed heart disease – pericardial constriction and restrictive cardiomyopathy.

Based on literature review, there has been a rise in the "frequency" of constrictive pericarditis patients due to prior cardiac surgery or radiation therapy.² Radiation therapy to the chest, particularly mediastinal, is a known risk factor for constrictive pericarditis as well as restrictive cardiomyopathy. Hemodynamically, cardiac filling is impaired in constrictive pericarditis due to abnormal pericardial restraint while in restrictive cardiomyopathy diastolic filling is impaired due to impaired ventricular relaxation. To distinguish these conditions, investigations include an echocardiogram, CT scan, CMR and/or cardiac catheterization.

Echocardiogram is usually the first line of imaging which provides hemodynamic as well as structural information. Based on the criteria used by the Mayo Clinic, presence of ventricular septal shift, medial mitral e' and hepatic vein expiratory diastolic reversal ratio have 97% specificity and 64% sensitivity to diagnose constrictive pericarditis. Medial e` velocity >9 cm/s alone has specificity and sensitivity of 81% and 83% respectively.<sup>3</sup> However, in our case, due to prior mitral valve replacement, the medial mitral e` could not be assessed for diagnostic purposes. In patients with restrictive cardiomyopathy, echocardiography usually reveals small left ventricles along with biatrial enlargement, E/A ratio >2, no significant respiratory variations across mitral valve and tissue Doppler peak e`<8 cm/sec.¹

In patients with CP, a CT scan can reveal a thickened pericardium (>2 mm), however in ~18% cases it may be normal.⁴ CT can also detect pericardial calcification and provides assessment of the cardiac structures to guide the peri-operative approach (especially in re-do open heart surgeries). It is especially helpful when echocardiogram is non-conclusive or if patient is unable to undergo CMR. On gadolinium delayed enhanced cardiac CMR imaging, the presence of pericardial late gadolinium enhancement (LGE) represents ongoing inflammation and can be a reliable indicator of response to anti-inflammatory therapy.^5-7 However, in our case LGE was not present suggesting the absence of ongoing pericarditis due which anti-inflammatory therapy may not provide any benefit.¹ CMR in patients with CP provides both structural and hemodynamic data with 93% diagnostic accuracy based on criteria such as: respirophasic discordance in atrioventricular valve inflow velocity variation, septal shift, pericardial thickness (>4 mm), diastolic septal bounce, and plethoric inferior vena cava (Table 2).⁸

Table 2

To confirm the diagnosis of CP, cardiac catheterization is performed to evaluate hemodynamics, specifically diastolic equalization of pressures in all cardiac chambers along with discordant changes in left and right ventricular systolic pressures with respiration prior to undergoing pericardiectomy. However, in our case, ventricular pressure changes were concordant consistent with restrictive physiology. Hence, it revealed that our patient had imaging features of both the constrictive pericarditis and restrictive cardiomyopathy.

Patients with confirmed constrictive pericarditis unresponsive to medical therapy should undergo radical pericardiectomy. However, it is important to be aware that patients with constrictive pericarditis due to radiation heart disease undergoing pericardiectomy have increased mortality compared to the other etiologies.^9-10 Unfortunately, mortality in patients with mixed pericardial constriction and restrictive cardiomyopathy is also higher compared to pericardial constriction alone.¹¹ Furthermore, it has been reported that after excluding for patients with radiation exposure, pericardial constriction in patients with a moderate compared to mild or no tricuspid regurgitation is associated with higher mortality after pericardiectomy.¹⁰

It was difficult to predict whether patient's symptoms would improve or worsen after pericardiectomy. Anti-inflammatory therapy could have been beneficial had this been transient constrictive pericarditis.⁷ Tricuspid regurgitation and right ventricular systolic function could worsen postoperatively and further complicate outcomes after pericardiectomy. Conversely, delaying surgical management could worsen overall prognosis and increase mortality. After detailed discussion with the patient, the patient opted for continued medical therapy with close outpatient follow up.

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References

1. Adler Y, Charron P, Imazio M, et al. 2015 ESC Guidelines for the diagnosis and management of pericardial diseases: The Task Force for the Diagnosis and Management of Pericardial Diseases of the European Society of Cardiology (ESC). Endorsed by: The European Association for Cardio-Thoracic Surgery (EACTS). Eur Hear J 2015;36:2921-64.
2. Welch TD. Constrictive pericarditis: diagnosis, management and clinical outcomes. Heart 2018;104:725-31.
3. Welch TD, Ling LH, Espinosa RE, et al. Echocardiographic diagnosis of constrictive pericarditis: Mayo Clinic criteria. Circ Cardiovasc Imaging 2014;7:526-34.
4. Talreja DR, Edwards WD, Danielson GK, et al. Constrictive pericarditis in 26 patients with histologically normal pericardial thickness. Circulation 2003;108:1852-57.
5. Cremer PC, Tariq MU, Karwa A, et al. Quantitative assessment of pericardial delayed hyperenhancement predicts clinical improvement in patients with constrictive pericarditis treated with anti-inflammatory therapy. Circ Cardiovasc Imaging 2015;8:1-7.
6. Zurick AO, Bolen MA, Kwon DH, et al. Pericardial delayed hyperenhancement with CMR imaging in patients with constrictive pericarditis undergoing surgical pericardiectomy: a case series with histopathological correlation. JACC Cardiovasc Imaging 2011;4:1180-91.
7. Feng D, Glockner J, Kim K, et al. Cardiac magnetic resonance imaging pericardial late gadolinium enhancement and elevated inflammatory markers can predict the reversibility of constrictive pericarditis after antiinflammatory medical therapy: a pilot study. Circulation 2011;124:1830-37.
8. Thavendiranathan P, Verhaert D, Walls MC, et al. Simultaneous right and left heart real-time, free-breathing CMR flow quantification identifies constrictive physiology. JACC Cardiovasc Imaging 2012;5:15-24.
9. Bertog SC, Thambidorai SK, Parakh K, et al. Constrictive pericarditis: etiology and cause-specific survival after pericardiectomy. J Am Coll Cardiol 2004;43:1445-52.
10. Góngora E, Dearani JA, Orszulak TA, Schaff HV, Li Z, Sundt TM III. Tricuspid regurgitation in patients undergoing pericardiectomy for constrictive pericarditis. Ann Thorac Surg 2008;85:163-70.
11. Yamada H, Tabata T, Jaffer SJ, et al. Clinical features of mixed physiology of constriction and restriction: echocardiographic characteristics and clinical outcome. Eur J Echocardiogr 2007;8:185-94.
12. Geske JB, Anavekar NS, Nishimura RA, Oh JK, Gersh BJ. Differentiation of constriction and restriction: complex cardiovascular hemodynamics. J Am Coll Cardiol 2016;68:2329-47.