Left ventricular function recovery in peripartum cardiomyopathy: a cardiovascular magnetic resonance study by myocardial T1 and T2 mapping

Transient Left Ventricular Dysfunction from Cardiomyopathies to Myocardial Viability: When and Why Cardiac Function Recovers

Transient left ventricular dysfunction (TLVD), a temporary condition marked by reversible impairment of ventricular function, remains an underdiagnosed yet significant contributor to morbidity and mortality in clinical practice. Unlike the well-explored atherosclerotic disease of the epicardial coronary arteries, the diverse etiologies of TLVD require greater attention for proper diagnosis and management. The spectrum of disorders associated with TLVD includes stress-induced cardiomyopathy, central nervous system injuries, histaminergic syndromes, various inflammatory diseases, pregnancy-related conditions, and genetically determined syndromes. Furthermore, myocardial infarction with non-obstructive coronary arteries (MINOCA) origins such as coronary artery spasm, coronary thromboembolism, and spontaneous coronary artery dissection (SCAD) may also manifest as TLVD, eventually showing recovery. This review highlights the range of ischemic and non-ischemic clinical situations that lead to TLVD, gathering conditions like Tako-Tsubo Syndrome (TTS), Kounis syndrome (KS), Myocarditis, Peripartum Cardiomyopathy (PPCM), and Tachycardia-induced cardiomyopathy (TIC). Differentiation amongst these causes is crucial, as they involve distinct clinical, instrumental, and genetic predictors that bode different outcomes and recovery potential for left ventricular function. The purpose of this review is to improve everyday clinical approaches to treating these diseases by providing an extensive survey of conditions linked with TLVD and the elements impacting prognosis and outcomes.

Prognostic value of mid-term cardiovascular magnetic resonance follow-up in patients with non-ischemic dilated cardiomyopathy: a prospective cohort study

BACKGROUND

The prognostic value of follow-up cardiovascular magnetic resonance (CMR) in dilated cardiomyopathy (DCM) patients is unclear. We aimed to investigate the prognostic value of cardiac function, structure, and tissue characteristics at mid-term CMR follow-up.

METHODS

The study population was a prospectively enrolled cohort of DCM patients who underwent guideline-directed medical therapy with baseline and follow-up CMR, which included measurement of biventricular volume and ejection fraction, late gadolinium enhancement, native T1, native T2, and extracellular volume. During follow-up, major adverse cardiac events (MACE) were defined as a composite endpoint of cardiovascular death, heart transplantation, and heart-failure readmission.

RESULTS

Among 235 DCM patients (median CMR interval: 15.3 months; interquartile range: 12.5-19.2 months), 54 (23.0%) experienced MACE during follow-up (median: 31.2 months; interquartile range: 20.8-50.0 months). In multivariable Cox regression, follow-up CMR models showed significantly superior predictive value than baseline CMR models. Stepwise multivariate Cox regression showed that follow-up left ventricular ejection fraction (LVEF; hazard ratio [HR], 0.93; 95% confidence interval [CI], 0.91-0.96; p < 0.001) and native T1 (HR, 1.01; 95% CI, 1.00-1.01; p = 0.030) were independent predictors of MACE. Follow-up LVEF ≥ 40% or stable LVEF < 40% with T1 ≤ 1273 ms indicated low risk (annual event rate < 4%), while stable LVEF < 40% and T1 > 1273 ms or LVEF < 40% with deterioration indicated high risk (annual event rate > 15%).

CONCLUSIONS

Follow-up CMR provided better risk stratification than baseline CMR. Improvements in the LVEF and T1 mapping are associated with a lower risk of MACE.

Utilities and Limitations of Cardiac Magnetic Resonance Imaging in Dilated Cardiomyopathy

Dilated cardiomyopathy (DCM) is one of the most common types of non-ischemic cardiomyopathy. DCM is characterized by left ventricle (LV) dilatation and systolic dysfunction without coronary artery disease or abnormal loading conditions. DCM is not a single disease entity and has a complex historical background of revisions and updates to its definition because of its diverse etiology and clinical manifestations. In cases of LV dilatation and dysfunction, conditions with phenotypic overlap should be excluded before establishing a DCM diagnosis. The differential diagnoses of DCM include ischemic cardiomyopathy, valvular heart disease, burned-out hypertrophic cardiomyopathy, arrhythmogenic cardiomyopathy, and non-compaction. Cardiac magnetic resonance (CMR) imaging is helpful for evaluating DCM because it provides precise measurements of cardiac size, function, mass, and tissue characterization. Comprehensive analyses using various sequences, including cine imaging, late gadolinium enhancement imaging, and T1 and T2 mapping, may help establish differential diagnoses, etiological work-up, disease stratification, prognostic determination, and follow-up procedures in patients with DCM phenotypes. This article aimed to review the utilities and limitations of CMR in the diagnosis and assessment of DCM.

Early detection and serial monitoring during chemotherapy-radiation therapy: Using T1 and T2 mapping cardiac magnetic resonance imaging

Purpose

To confirm the ability of native T1 and T2 values in detecting and monitoring early myocardial injuries of chest radiotherapy in neoplasm patients.

Materials and methods

Fifteen participants received non-anthracycline chemotherapy and chest radiotherapy, and 30 age/gender-matched controls were enrolled in this prospective study. Cardiac magnetic resonance scans were performed within 2 days, 3 months, and 6 months after chest radiotherapy. Myocardial native T1 and T2 values were measured in irradiated and nonirradiated areas. Meanwhile, the parameters of left ventricular function and left ventricular myocardial strain were obtained.

Results

There were no significant differences in left ventricular function, native T1, T2, and strain between patients and controls before chest radiotherapy. In 15 participants who were followed up for 6 months, there was a significant change only in left ventricular ejection fraction (LVEF) among baseline and the first follow-up (P = 0.021), while the adjusted P-value was higher than 0.05 after Bonferroni correction, as well as other parameters. Native T1 values were elevated at 3 and 6 months in irradiated areas compared with baseline (1,288.72 ± 66.59 ms vs. 1,212.51 ± 45.41 ms; 1,348.01 ± 54.16 ms vs. 1,212.51 ± 45.41 ms; P &lt; 0.001 for both). However, T2 values only changed at 3 months in irradiated areas compared with baseline (44.21 ± 3.35 ms vs. 39.14 ± 1.44 ms; P = 0.006). Neither the native T1 nor T2 values changed in nonirradiated areas during the follow-up period (all P &gt; 0.05). There were no significant differences in strain changes during the follow-up period (all P &gt; 0.05).

Conclusion

Native T1 and T2 values elevated at 3 months after chest radiotherapy, whereas LVEF showed no significant change during the 6-month follow-up.

Meta-Analysis of Long-Term (>1 Year) Cardiac Outcomes of Peripartum Cardiomyopathy

Peripartum cardiomyopathy is the development of heart failure toward the end of pregnancy or in the months after delivery in the absence of other attributable causes, with left ventricular systolic dysfunction and a left ventricular ejection fraction (LVEF) generally <45%. Given that patients are relatively young at the time of diagnosis, this study was performed to summarize current evidence surrounding the long-term cardiac outcomes. MEDLINE, Embase, Cochrane CENTRAL, and CINAHL were searched for original studies that reported long-term (>1 year) patient outcomes. Of the 3,144 total records identified, 62 studies involving 4,282 patients met the selection criteria. The mean LVEF was 28% at diagnosis and 47% at the time of the last follow-up. Approximately half of the patients achieved myocardial recovery (47%), most commonly defined as an LVEF >50% (n = 21). The prevalence of implantable cardioverter-defibrillator use, left ventricular assist device implantation, and heart transplantation was 12%, 7%, and 11%, respectively. The overall all-cause mortality was 9%, and despite having more cardiovascular risk factors, patients residing in high-income countries had superior outcomes, including reduced rates of mortality.

Peripartum cardiomyopathy: risk factors and predictors of outcome

PURPOSE OF REVIEW

Peripartum cardiomyopathy (PPCM) contributes significantly to maternal morbidity and mortality worldwide. In this review, we describe the present-day epidemiology and current understanding of the pathogenesis of PPCM. We provide an updated approach to diagnosis and management of PPCM, and discuss risk factors and predictors of outcome.

RECENT FINDINGS

The highest incidences of PPCM have been reported in African, Asian, and Caribbean populations. Contemporary literature supports a 'two-hit' hypothesis, whereby the 'first hit' implies a predisposition, and the 'second hit' refers to an imbalanced peripartal hormonal milieu that results in cardiomyopathy. Whereas a half of patients will have left ventricular (LV) recovery, a tenth do not survive. Clinical findings and special investigations (ECG, echocardiography, cardiac MRI, biomarkers) can be used for risk stratification. Frequent prescription of guideline-directed medical therapy is associated with improved outcomes.

SUMMARY

Despite advances in elucidating the pathogenesis of PPCM, it remains unclear why only certain women develop the disease. Moreover, even with better diagnostic work-up and management, it remains unknown why some patients with PPCM have persistent LV dysfunction or die. Future research should be aimed at better understanding of the mechanisms of disease and finding new therapies that could improve survival and LV recovery.

Review of Randomized Controlled Trials in Patients with Peripartum Cardiomyopathy

INTRODUCTION

Peripartum cardiomyopathy (PPCM) is a rare but potentially lifethreatening disease, defined as idiopathic cardiomyopathy occurring towards the end of pregnancy or in the months following delivery, abortion or miscarriage. We aim to raise awareness of this condition and give an overview of current knowledge as well as an insight and comparison of clinical trials focusing on randomized controlled trials.

MATERIAL AND METHODS

Systematic literature searches were conducted using PubMed up to December 2021. Studies published involving clinical trials and interventions in women with PPCM after 1970 were selected.

RESULTS

Randomized controlled trials have shown that the addition of Bromocriptine to standardized heart failure therapy improves outcome in terms of recovery of Left Ventricular Ejection Fraction (LVEF), symptoms and death. Bromocriptine 2.5 mg twice daily for two weeks followed by 2.5 mg once daily for six weeks had the best trend and outcome. The addition of Levosimendan to standardized heart failure therapy had no effect, whereas the addition of Selenium improved heart failure symptoms but did not reduce risk in terms of unrecovered LVEF or death. One prospective study showed potential usage of TNF-alfa inhibitors, but was never tried in a randomized clinical trial.

CONCLUSION

PPCM is a rare and potentially fatal disease. New insights on pathophysiology, genetics and clinical studies, particularly randomized controlled trials, have shown that the addition of Bromocriptine has a beneficial effect in terms of improved LVEF and death. However, some clinical studies have shown promising results using anti-inflammatory pharmacological agents with an improvement in LVEF. We suggest that targeting an anti-inflammatory route may prove beneficial in patients with PPCM. However, further research is highly warranted.

The outcome of peripartum cardiomyopathy patients-single center experience

OBJECTIVE

Peripartum cardiomyopathy (PPCM) diagnosis made by excluding identifiable causes of heart failure (HF) and occurs end of the pregnancy or during the postpartum period of five months. It presents a clinical HF spectrum with left ventricular systolic dysfunction.

BACKGROUND

The purpose of this study is to retrospectively evaluate the clinical characteristics, cardiac magnetic resonance (CMR) imaging features, and end-points consisting of left ventricle recovery, left ventricular assist device implantation, heart transplantation, and all-cause mortality.

METHOD

Outpatient HF records between 2008 to 2021 were screened. Thirty-seven patients were defined as PPCM. Twenty-five patients had CMR evaluation at the time of diagnosis, and six patients were re-evaluated with CMR.

RESULTS

The mean age was 30.5 ± 5.6 years, and the mean LVEF was 28.2% ± 6.7%. In 13(35.7%) patients, LVEF recovered during the follow-up course. The median recovery time was 281(IQR [78-358]) days. LVEF on CMR was 35.3 ± 10.5, and three patients exhibited late gadolinium enhancement(LGE) patterns. Sub-endocardial and mid-wall uptake pattern types were detected. 18(75%) patients met the Petersen left ventricle non-compaction cardiomyopathy(LVNC) criteria. Patients with NC/C ratio lower than 2.3 had lower LVEDVi and LVESVi (124.9 ± 35.4, 86.4 ± 7.5, p = .003; 86.8 ± 34.6, 52.6 ± 7.6, p = .006), respectively. The median follow-up time was 2129 (IQR [911-2634]) days. The primary endpoint-free 1-year survival was 88.9% (event rate 11.1%), and 5-year survival was 75.7% (event rate 24.3%).

CONCLUSION

In a retrospective cohort of PPCM patients, 35.7% of patients' LVEF recovered, and the primary end-point of free-5-year survival was 75%. Twenty-five patients were assessed with CMR; three of four met the Petersen CMR-derived LVNC at initial evaluation.

Peripartum Mid-Ventricular-Type Takotsubo Cardiomyopathy After Cesarean Delivery

There are several causes of heart failure during pregnancy and the peripartum period, which include peripartum cardiomyopathy, Takotsubo cardiomyopathy or stress cardiomyopathy, exacerbation of a preexisting cardiomyopathy, and acute myocarditis. It is important to determine the cause of the heart failure as the medical treatment may be different based on the diagnosis. However, it has been sometimes challenging to diagnose the cause because of the limited diagnostic tools, especially in pregnant women. Cardiac MRI can characterize myocardial injury and can be used to track the changes in myocardial tissue. We herein report a 35-year-old woman diagnosed with peripartum mid-ventricular-type Takotsubo cardiomyopathy, who was referred to our hospital due to worsening dyspnea the day after cesarean delivery. On admission, electrocardiography showed sinus tachycardia and poor progression of R waves in the precordial leads. Bedside echocardiography revealed severe hypokinesis in the mid- and apical left ventricle (LV) with a LV ejection fraction of 20%. Cardiac catheterization showed normal coronary arteries, and myocardial biopsy revealed contraction band necrosis. On acute phase (Day 4), cardiac MRI showed prolonged native T1 and T2, and severe hypokinesis and decreased regional longitudinal peak strain in the mid-anterior LV wall. During the 1^st week, precordial ST fluctuation was observed, and LV wall motion had gradually recovered. Repeat cardiac MRI revealed normalized LV wall motion and shortened values for global native T1 and T2. Thus, she was diagnosed with peripartum Takotsubo cardiomyopathy. Serial cardiac MRI may be able to differentiate Takotsubo cardiomyopathy during pregnancy and the peripartum period from other preexisting cardiomyopathies.

Prognostic value of various markers in recovery from peripartum cardiomyopathy: a systematic review and meta-analysis

AIMS

The aetiology of peripartum cardiomyopathy (PPCM) is still not clear, and it is unknown who would recover from PPCM. In this meta-analysis, for the first time, we aimed to explore the prognostic value of potential baseline factors that may help predict recovery in patients with PPCM.

METHODS

A systematic approach following the Meta-analysis of Observational Studies in Epidemiology guideline was taken by using appropriate keywords in PubMed, Scopus, and Embase databases. Studies that had compared different clinical and paraclinical markers at the time of diagnosis related to cardiovascular function between recovered and non-recovered patients with PPCM were included. To find potential predictors of recovery, the odds ratio (OR) was calculated for different parameters using the random-effects model.

RESULTS

Eighteen cohort studies including 1047 patients with PPCM were enrolled. Six markers out of the 11 potentially eligible markers were associated with PPCM recovery. Baseline echocardiographic parameters [left ventricular ejection fraction (LVEF) (OR = 4.84 [2.53; 9.26]), left ventricular end-diastolic diameter (OR = 3.67 [2.58; 5.23]), left ventricular end-systolic diameter (OR = 3.99 [2.27; 7.02]), and fractional shortening (OR = 6.14 [1.81; 20.85])] were strong predictors of PPCM recovery. Systolic blood pressure (OR = 2.16 [1.38; 3.38]) and diastolic blood pressure (OR = 2.06 [1.07; 3.96]) at diagnosis were also associated with recovery.

CONCLUSIONS

Patients with PPCM who have a higher baseline LVEF, lower left ventricular diameters, and higher blood pressure levels have a greater chance to recover from PPCM.

T2 mapping in myocardial disease: a comprehensive review

Cardiovascular magnetic resonance (CMR) is considered the gold standard imaging modality for myocardial tissue characterization. Elevated transverse relaxation time (T2) is specific for increased myocardial water content, increased free water, and is used as an index of myocardial edema. The strengths of quantitative T2 mapping lie in the accurate characterization of myocardial edema, and the early detection of reversible myocardial disease without the use of contrast agents or ionizing radiation. Quantitative T2 mapping overcomes the limitations of T2-weighted imaging for reliable assessment of diffuse myocardial edema and can be used to diagnose, stage, and monitor myocardial injury. Strong evidence supports the clinical use of T2 mapping in acute myocardial infarction, myocarditis, heart transplant rejection, and dilated cardiomyopathy. Accumulating data support the utility of T2 mapping for the assessment of other cardiomyopathies, rheumatologic conditions with cardiac involvement, and monitoring for cancer therapy-related cardiac injury. Importantly, elevated T2 relaxation time may be the first sign of myocardial injury in many diseases and oftentimes precedes symptoms, changes in ejection fraction, and irreversible myocardial remodeling. This comprehensive review discusses the technical considerations and clinical roles of myocardial T2 mapping with an emphasis on expanding the impact of this unique, noninvasive tissue parameter.

Myocardial oedema: pathophysiological basis and implications for the failing heart

Myocardial fluid homeostasis relies on a complex interplay between microvascular filtration, interstitial hydration, cardiomyocyte water uptake and lymphatic removal. Dysregulation of one or more of these mechanisms may result in myocardial oedema. Interstitial and intracellular fluid accumulation disrupts myocardial architecture, intercellular communication, and metabolic pathways, decreasing contractility and increasing myocardial stiffness. The widespread use of cardiac magnetic resonance enabled the identification of myocardial oedema as a clinically relevant imaging finding with prognostic implications in several types of heart failure. Furthermore, growing experimental evidence has contributed to a better understanding of the physical and molecular interactions in the microvascular barrier, myocardial interstitium and lymphatics and how they might be disrupted in heart failure. In this review, we summarize current knowledge on the factors controlling myocardial water balance in the healthy and failing heart and pinpoint the new potential therapeutic avenues.

Peripartum Cardiomyopathy: Diagnostic and Prognostic Value of Cardiac Magnetic Resonance in the Acute Stage

This study aimed to evaluate the diagnostic and prognostic value of cardiac magnetic resonance in acute peripartum cardiomyopathy (PPCM). A total of 17 patients with PPCM in the acute stage and 15 healthy controls were retrospectively analyzed regarding myocardial function, edema, late gadolinium enhancement (LGE), and T1 and T2 mappings (T1, T2). Echocardiographic follow-ups were performed. Functional recovery was defined as a left ventricular ejection fraction (LVEF) of ≥50%. Patients with PPCM displayed biventricular dysfunction with reduced myocardial strain parameters and left ventricular and atrial dilatation, as well as diffuse myocardial edema (T2 signal intensity ratio: 2.10 ± 0.34 vs. 1.58 ± 0.21, p < 0.001; T1: 1070 ± 51 ms vs. 980 ± 28 ms, p = 0.001; T2: 63 ± 5 ms vs. 53 ± 2 ms, p < 0.001). Visual myocardial edema was present in 10 patients (59%). LGE was positive in 2 patients (12%). A total of 13 patients (76%) showed full LVEF recovery. The absence of visual myocardial edema and impairment of strain parameters were associated with delayed LVEF recovery. Multivariable Cox regression analysis revealed global longitudinal strain as an independent prognostic factor for LVEF recovery. In conclusion, biventricular systolic dysfunction with diffuse myocardial edema seems to be present in acute PPCM. Myocardial edema and strain may have prognostic value for LVEF recovery.

Clinical Features and Outcomes of Peripartum Cardiomyopathy in Nigeria

BACKGROUND

Nigeria has the highest incidence of peripartum cardiomyopathy (PPCM) in the world. However, data on PPCM-related outcomes are limited.

OBJECTIVES

The purpose of this study was to examine the clinical profile, myocardial remodeling, and survival of patients with PPCM in Nigeria.

METHODS

This study consecutively recruited 244 PPCM patients (median 7 months postpartum) at 14 sites in Nigeria and applied structured follow-up for a median of 17 months (interquartile range: 14 to 20 months). Left ventricular reverse remodeling (LVRR) was defined as the composite of left ventricular (LV) end-diastolic dimension <33 mm/m² and absolute increase in left ventricular ejection fraction (LVEF) ≥10%. LV full recovery was defined as LVEF ≥55%.

RESULTS

Overall, 45 (18.7%) patients died during follow-up. Maternal age <20 years (hazard ratio [HR]: 2.40; 95% confidence interval (CI): 1.27 to 4.54), hypotension (HR: 1.87; 95% CI: 1.02 to 3.43), tachycardia (HR: 2.38; 95% CI: 1.05 to 5.43), and LVEF <25% at baseline (HR: 2.11; 95% CI: 1.12 to 3.95) independently predicted mortality. Obesity (HR: 0.16; 95% CI: 0.04 to 0.55) and regular use of beta-blockers at 6-month follow-up (HR: 0.20; 95% CI: 0.09 to 0.41) were independently associated with reduced risk for mortality. In total, 48 patients (24.1%) achieved LVRR and 45 (22.6%) achieved LV full recovery. LVEF <25% at baseline (HR: 0.66; 95% CI: 0.47 to 0.92) and regular use of beta-blockers at 6-month follow-up (HR: 1.62; 95% CI: 1.17 to 2.25) independently determined the risk for LV full recovery. Progressive reverse remodeling of all cardiac chambers was observed. In total, 18 patients (7.4%) were hospitalized during the study.

CONCLUSIONS

This is the largest study of PPCM in Africa. Consistent with late presentations, the mortality rate was high, whereas frequencies of LVRR and LV full recovery were low. Several variables predicted poor outcomes, and regular use of beta-blockers correlated with late survival and LV functional recovery.

The Role of MRI in Prognostic Stratification of Cardiomyopathies

PURPOSE OF THE REVIEW

The aim of this review was to discuss the role of cardiac magnetic resonance (CMR) for the prognostic stratification of cardiomyopathies, highlighting strengths and limitations.

RECENT FINDINGS

CMR is considered as a diagnostic pillar in the management of non-ischemic cardiomyopathies. Over the last years, attention has shifted from CMR's diagnostic capability towards prognostication in the various settings of cardiomyopathies. CMR is considered the gold standard imaging technique for the evaluation of ventricular volumes and systolic function as well as providing non-invasive virtual-histology by means of specific myocardial tissue characterization pulse sequences. CMR is an additive tool to risk stratifying patients and to identify those that require strict monitoring and more aggressive treatment.