Successful intervention for decompensated heart failure with complicated pathophysiologies with complex interdependence: a case report

Abstract

Introduction

Current evidence-based guidelines on valvular disease and heart failure (HF) recommend cardiac resynchronization therapy (CRT) after optimal medical treatment (OMT) in patients with functional mitral regurgitation (FMR) as first-line treatment.¹ However, this strategy focused on long-term outcomes, and there is limited evidence for cases of acute decompensated HF that do not respond to OMT. Furthermore, the coexistence of an atrial septal defect (ASD) with severe left ventricular dysfunction (LVD) and severe FMR is rare in older patients. Determining the appropriate first-line treatment in such patients requires careful consideration of the underlying pathophysiology along with the correct OMT. We present the complex case of a patient with LVD, FMR, and iatrogenic ASD (IASD) who presented with acute decompensated HF refractory to the initial OMT.

Summary figure

Case presentation

A 72-year-old man in cardiogenic shock was admitted to our hospital. His medical history included angina pectoris and paroxysmal AF. He had undergone percutaneous coronary intervention for the left ascending artery and pulmonary vein isolation 3 and 1 year before admission, respectively. At the time of admission, his heart rate was 112 b.p.m. with an irregular rhythm, blood pressure was 78/52 mmHg on intravenous catecholamine, and oxygen saturation was 94% on room air. Physical examination revealed bilateral fine pulmonary crackles, a holosystolic apical murmur, leg oedema, and cold limbs. Chest radiography revealed pulmonary oedema and pleural effusion, while electrocardiography revealed tachycardia due to AF. Transthoracic echocardiography revealed severe LVD [ejection fraction (EF) 15%, a decline from the 24% measured 2 years earlier], severe FMR [regurgitant fraction (RF) 55%, effective regurgitant orifice area (ERO) 0.54 cm²], and left-to-right shunts through IASDs formed via atrial septal puncture during the pulmonary vein isolation (Qp/Qs: 2.1; Figure 1). Tricuspid annular plane systolic excursion was 23.7 mm. Laboratory testing showed elevated serum creatinine (1.97 mg/dL), total bilirubin (1.55 mg/dL), and brain natriuretic peptide (1500 pg/mL) levels; the troponin I level was within the normal range (0.018 ng/mL). Coronary angiography revealed no significant coronary artery stenosis, while RHC revealed elevated PAWP (22 mmHg), pulmonary artery pressure (systolic, 43 mmHg; diastolic, 18 mmHg; mean, 30 mmHg), and right atrial pressure (10 mmHg).

Figure 1

On admission, chest radiography showed pulmonary oedema and pleural effusion, and an electrocardiogram after electrical cardioversion revealed left bundle block with QRS duration of 152 ms. Transthoracic echocardiography showed severe functional mitral regurgitation (regurgitant fraction 55%, effective regurgitant orifice area 0.54 cm²) and left-to-right shunts through iatrogenic atrial septal defects (Qp/Qs 2.1).

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The patient was stabilized in our ICU using electrical cardioversion, IABP insertion, and intravenous dobutamine and furosemide. An electrocardiogram after electrical cardioversion revealed sinus rhythms with left bundle block and QRS duration of 152 ms (Figure 1). On Day 10, after haemodynamic stabilization, the IABP was removed. The patient was gradually weaned off dobutamine, and we initiated OMT with an angiotensin receptor blocker, a mineralocorticoid receptor antagonist, a sodium–glucose cotransporter 2 inhibitor, and oral diuretics. These medications were carefully titrated, eventually transitioning to Entresto (replacing valsartan) 50 mg, spironolactone 25 mg, dapagliflozin 10 mg, furosemide 40 mg, tolvaptan 18.75 mg, and pimobendan 5 mg. However, despite the patient maintaining sinus rhythm and receiving OMT for >1 month, the severe dyspnoea on exertion, pulmonary oedema, and pleural effusion did not improve. On Day 45, TTE did not show improvement in severe LVD (EF 18%), FMR (RF 62%, ERO 0.63 cm²), and haemodynamic left-to-right shunt through IASD (Qp/Qs: 2.1; Figure 2). Pulmonary artery wedge pressure also did not improve (28 mmHg) on RHC. On Day 48, the heart team discussed additional interventional therapy options and selected CRT implantation.

Figure 2

Two weeks after cardiac resynchronization therapy, transthoracic echocardiography showed improved functional mitral regurgitation (regurgitant fraction 38%, effective regurgitant orifice area 0.16 cm²) and iatrogenic atrial septal defect (Qp/Qs 1.3; A’, B’) compared to before cardiac resynchronization therapy (regurgitant fraction 62%, effective regurgitant orifice area 0.63 cm², and Qp/Qs 2.1; A, B).

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After CRT implantation on Day 51, the patient’s symptoms gradually improved. After confirming the resolution of pulmonary congestion, bisoprolol 0.3125 mg was introduced. Two weeks later, significant improvements in cardiac function (EF 21%), FMR [RF 38%, regurgitant volume (RV) 24 mL, ERO 0.18 cm²], left-to-right shunts through the IASD (Qp/Qs: 1.3; Figure 2), and PAWP (10 mmHg) were observed. Furthermore, chest radiography showed complete resolution of the pulmonary oedema and pleural effusion (Figure 3). Because of his successful recovery, he was discharged on Day 76.

Figure 3

Residual pulmonary oedema and pleural effusion were observed after optimal medication therapy. (A) Two weeks after cardiac resynchronization therapy, pulmonary oedema and pleural effusion were improved (C) and QRS duration reduced from 152 to 134 ms (B, D).

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Discussion

Complicated pathophysiological conditions including LVD, severe FMR, and IASD were observed in this case. Various device-based therapeutic interventions are available for each of these pathophysiologies, but each one exhibits complex interdependence. Therefore, in cases like these, if decompensated HF is not controlled with OMT, it is crucial to consider which strategy should be selected as the next therapy.

Reduction of FMR could improve left atrial (LA) parameters such as LA volume, pressure, and stiffness^2,3 and is reportedly associated with decreasing AF burden or recurrence.^4,5 Additionally, decreased LA pressure due to transcatheter mitral valve repair (TMVR) is reportedly associated with the improvement of IASDs.⁶

In this case, neither the right atrium nor the right ventricle was dilated, and right ventricular function remained intact, thus excluding ASD as the main pathophysiological issue. On the other hand, PAWP remained elevated despite the left–right septal shunt relieving the LA pressure. Increased LA volume and elevated LA pressure, resulting from MR, could potentially escalate left-to-right shunt flow. In light of these factors, FMR rather than IASD was considered the primary cause of the decompensating haemodynamic state. Thus, the reduction of FMR was determined to be the best next step therapy. To reduce the FMR, we had two options: TMVR or CRT in addition to OMT.

Transcatheter mitral valve repair has been reported to be an effective alternative treatment option for secondary MR in high-risk and inoperable patients.¹ However, most reports on TMVR have excluded haemodynamically unstable cases, and the role of TMVR in patients in the acute phase has not been well described. Additionally, the effect of TMVR in patients with a very low EF (<20%), such as in this case, is unknown. In patients with a very low EF, especially those with decompensated HF, transient myocardial dysfunction due to an abrupt increase in afterload after MR reduction should be considered.⁷ Moreover, TMVR can increase forward stroke volume in cases of FMR by reducing MR and improving EF through left ventricular reverse remodelling; however, the effect is generally observed in the chronic phase, and its impact in the acute phase remains uncertain.^8,9 Similarly, CRT implantation increases cardiac output by establishing contraction resynchronization and left ventricular reverse remodelling. Cardiac resynchronization therapy has also been reported to improve the FMR immediately in 39–43% of cases.^10,11 Although the long-term decrease in FMR due to CRT is secondary to left ventricular remodelling, the acute effect of CRT on FMR is driven by the mechanism correcting papillary muscle dyssynchrony.¹² In patients with HF and left bundle branch abnormality, post-CRT changes in interpapillary muscle activation time delay, as measured by echocardiographic strain imaging, have been reported to correlate significantly with immediate improvement in MR.¹³ Additionally, speckle-tracking analysis conducted both at baseline and after CRT implantation could be valuable in predicting the acute effect of CRT on FMR.

When treating decompensated HF with complicated pathophysiologies that exhibit complex interdependence that is uncontrolled despite OMT, it is important to consider which pathophysiology should be addressed first and discuss appropriate interventions with the heart team. In conclusion, we encountered a case with complicated multiple pathophysiological conditions, including LVD, severe FMR, and IASD. Functional mitral regurgitation immediately improved after CRT implantation and IASD-mediated shunting.

Lead author biography

Dr Makio Muraishi is an interventional cardiologist at the Tokyo Bay Urayasu Ichikawa Medical Center.

Consent: The authors confirm that written consent for submission and publication of this case report, including the images and associated text, has been obtained from the patient in line with COPE guidance.

Funding: None declared.

Data availability

The data are available from the corresponding author upon reasonable request.

References

Author notes