Coronary Microvascular Dysfunction in Takotsubo Syndrome Assessed by Angiography-Derived Index of Microcirculatory Resistance: A Pressure-Wire-Free Tool

Coronary microvascular dysfunction in patients with Takotsubo syndrome

BACKGROUND

The pathophysiology of Takotsubo syndrome (TTS) remains incompletely understood. While coronary microvascular dysfunction (CMD) is a potential pathophysiologic mechanism, evidence is limited.

OBJECTIVES

We sought to evaluate CMD in patients with TTS.

METHODS

Consecutive patients diagnosed with TTS were included and underwent coronary angiography with invasive microvascular function evaluation, including fractional flow reserve, Coronary Flow Reserve (CFR), Index of Microcirculatory Resistance (IMR), and Resistive Reserve Ratio (RRR). Patients had an echocardiography evaluation during their index admission and at approximately 6 weeks.

RESULTS

Thirty patients were included (mean age 74 ±9, 90 % female). Twenty-five patients (83 %) had at least one abnormal coronary microvascular function parameter. Abnormal parameters included CFR<2.5 in 20 patients (67 %), IMR>25 in 18 patients (60 %), and RRR<3.5 in 25 (83 %). Longer time from symptoms to angiography correlated with a higher CFR (r = 0.51, P<0.01), and had an area under the receiver operating characteristic curve of 0.793 (95 % CI 0.60-0.98) for pathologic CFR. Patients with emotional trigger had a lower rate of pathologic IMR compared with non-emotional trigger (36 % vs 81 %, p = 0.01). Follow up echocardiography performed at a median of 1.5 months (IQR 1.15-6) showed an improvement in left ventricular ejection fraction for all patients (from mean of 40 % to 57 %).

CONCLUSION

CMD was present in most patients with TTS. The role of microvascular function in TTS may vary according to the clinical presentation and RRR may be more sensitive for the diagnosis of CMD in TTS.

Impact of Coronary Microvascular Dysfunction in Takotsubo Syndrome: Cause, Consequence or Both?

Takotsubo syndrome (TTS) is an acute cause of heart failure characterized by a reversible left ventricular (LV) impairment usually induced by a physical or emotional trigger. TTS is not always a benign disease since it is associated with a relatively higher risk of life-threatening complications, such as cardiogenic shock, ventricular arrhythmias, respiratory failure, cardiopulmonary resuscitation and death. Despite notable advancements in the management of patients with TTS, physiopathological mechanisms underlying transient LV dysfunction remain largely unknown. Since TTS carries similar prognostic implications than acute myocardial infarction, the identification of mechanisms and predictors of worse prognosis remain key to establish appropriate treatments. The greater prevalence of TTS among post-menopausal women and the activation of the neuro-cardiac axis triggered by physical or emotional stressors paved the way forward to several studies focused on coronary microcirculation and impaired blood flow as the main physiopathological mechanisms of TTS. However, whether microvascular dysfunction is the cause or a consequence of transient LV impairment remains still unsettled. This review provides an up-to-date summary of available evidence supporting the role of microvascular dysfunction in TTS pathogenesis, summarizing contemporary invasive and non-invasive diagnostic techniques for its assessment. We will also discuss novel techniques focused on microvascular dysfunction in TTS which may support clinicians for the implementation of tailored treatments.

Impact of age on the outcomes of Takotsubo syndrome

BACKGROUND

The impact on age on the short-term and long-term prognosis in patients with Takotsubo syndrome (TTS) is unclear. We aimed to evaluate whether age has prognostic implications during hospital stay and long-term follow-up of TTS patients.

METHODS

688 consecutive patients were admitted for TTS in 7 tertiary centers from January-2008 to June-2021. We divided our cohort into two groups (patients <75 years and ≥75 years). Clinical, analytical, and hemodynamic variables as well as in-hospital management were registered and compared between groups. Mortality rates during hospital stay and follow-up were assessed. Adverse cardiovascular events (ACE) were defined as the composite of cardiovascular death, heart failure event, acute myocardial infarction, stroke and symptomatic arrhythmia.

RESULTS

Median age was 74.7 years and 49.4 % were ≥75 years. 86.9 % were women and 22.3 % were secondary forms of TTS. In-hospital mortality was 3.6 % (1.5 % cardiovascular). Median clinical follow-up was 4.3 years. Mortality during the follow-up period was 23 % (5.0 % cardiovascular) while ACE were 22.5 %, mainly due to heart failure events. Kaplan-Meier curves showed both higher rates of mortality and ACE in ≥75 years group (30.2 % vs 15.8 %; p < 0.001 and 28.3 % vs 16.7 %; p < 0.001). Age was independently associated with higher rates of overall mortality and ACE in patients with TTS. Hypertension, absence of sinus rhythm, Killip class > I and a more impaired coronary microvascular resistance were also associated to ACE in TTS patients.

CONCLUSIONS

Advanced age was associated with higher rate of overall mortality and ACE during long-term follow-up in TTS patients.

Effects of cardiovascular risk factors and pre-existing diseases on the short-term outcome of Takotsubo syndrome

BACKGROUND

The effects of cardiovascular risk factors (CVRF) on the development of most acute cardiac conditions are well established; however, little is known about the frequency and effects of CVRF in Takotsubo syndrome (TTS) patients.

OBJECTIVE

The aim of our study was to compare the frequency of CVRF and pre-existing diseases (PD) of TTS patients to ST-elevation myocardial infarction (STEMI) patients and analyze their effects on short-term outcome.

METHODS

We analyzed the frequency of CVRF (hypertension, hyperlipidemia, type II diabetes mellitus, smoking, chronic kidney disease, family history) as well as somatic and psychiatric PD at admission in TTS patients and compared them with STEMI patients. Their effect on short-term outcome was calculated using a combined endpoint of cardiogenic shock, cardiopulmonary resuscitation, mechanical ventilation, and/or in-hospital death.

RESULTS

In total, 150 TTS and 155 STEMI patients were included in our study. We observed a higher frequency of psychiatric (30% vs. 7%, p < 0.001), neurological (5% vs. 0%, p = 0.01), and pulmonary (18% vs. 5%, p < 0.001) PD in TTS patients as compared to STEMI patients. There were less smokers (47% vs. 61%, p = 0.03) and patients with hyperlipidemia (24% vs. 51%, p < 0.001) in the TTS cohort than in the STEMI cohort. None of the CVRF or PD behaved as an independent predictor for adverse short-term outcome in TTS patients.

CONCLUSION

Psychiatric, neurological, and pulmonary pre-existing diseases are more common in TTS than in STEMI patients. Interestingly, PD and CVRF do not seem to have any impact on the short-term outcome of TTS patients.

Coronary microvascular dysfunction in Takotsubo syndrome: an analysis using angiography-derived index of microcirculatory resistance

BACKGROUND

Coronary microvascular dysfunction (CMD) has been proposed as a crucial factor in the pathophysiology of Takotsubo syndrome (TTS). The angiography-derived index of microcirculatory resistance (caIMR) offers an alternative to conventional hyperemic wire-based IMR to assess CMD. We aimed to evaluate CMD's prevalence, transience, and impact on in-hospital outcomes in TTS.

METHODS

All three coronary arteries of 96 patients with TTS were assessed for their coronary angiography derived Index of microcirculatory Resistance (caIMR) and compared to non-obstructed vessels of matched patients with ST-elevation myocardial infarction. Further, the association between caIMR and the TTS-specific combined in-hospital endpoint of death, cardiac arrest, ventricular arrhythmogenic events and cardiogenic shock was investigated.

RESULTS

Elevated IMR was present in all TTS patients, with significantly elevated caIMR values in all coronary arteries compared to controls. CaIMR did not differ between apical and midventricular TTS types. CaIMR normalized in TTS patients with follow-up angiographies performed at a median of 28 months (median caIMR at event vs follow-up: LAD 34.8 [29.9-41.1] vs 20.3 [16.0-25.3], p < 0.001; LCX: 38.7 [32.9-50.1] vs 23.7 [19.4-30.5], p < 0.001; RCA: 31.7 [25.0-39.1] vs 19.6 [17.1-24.0], p < 0.001). The extent of caIMR elevation significantly correlated with the combined in-hospital endpoint (p = 0.036).

CONCLUSION

TTS patients had evidence of elevated caIMR in at least one coronary artery with a trend towards higher LAD caIMR in apical type TTS and normalization after recovery. Furthermore, extent of caIMR elevation was associated with increased risk of in-hospital MACE of TTS patients.

An Extensive Review on Imaging Diagnosis Methods in Takotsubo Syndrome

Takotsubo Syndrome (TS) is an acute, reversible cardiac dysfunction, with complex, not entirely understood pathophysiology and heterogeneous clinical picture. Imaging methods each have a crucial role in the diagnosis, in-hospital management, short term and long term follow up. Coronary angiography needs to be performed, especially in the setting of a suspected acute coronary syndrome, in order to rule out coronary artery disease. Echocardiography plays a central role both in the acute and the chronic phase. It is the first imaging investigation performed in patients with TS, valuable to diagnose systolic dysfunction, the wall motion pattern and early complications. Cardiac magnetic resonance tissue characterization provides an essential role in the differential diagnosis of TS with other non-ischemic causes of systolic dysfunction. This review focuses on the imaging methods and the important part they play in the complex management of the disease.

Coronary microvascular dysfunction is a hallmark of all subtypes of MINOCA

INTRODUCTION

Myocardial infarction without obstructive coronary artery disease (MINOCA) is a heterogeneous clinical condition presenting with myocardial necrosis not due to an obstruction of a major coronary artery. Recently, a relevant role of coronary microvascular dysfunction (CMD) in the pathogenesis of MINOCA has been suggested; however, data on this are scarce. Particularly, it is unclear if CMD is equally present in all subtypes of MINOCA or differentially identifies one or more of these conditions. Therefore, the aim of this study was to assess CMD in all three coronary vessels of MINOCA patients, relating it with the clinical subtype.

METHODS

We retrospectively assessed coronary microvascular function in all three coronary territories by means of angiography-based index of microvascular resistance (aIMR) in 92 patients (64 with working diagnosis of MINOCA, 28 control patients). To further assess the association of CMD with MINOCA subtypes, MINOCA patients were subdivided according to clinical data in coronary cause (n = 13), takotsubo (n = 13), infiltrative or inflammatory cardiomyopathy (n = 9) or unclear (n = 29).

RESULTS

Patients with working diagnosis of MINOCA showed a significantly elevated average aIMR compared to control patients (30.5 ± 7.6 vs. 22.1 ± 5.9, p < 0.001) as a marker of a relevant CMD; these data were consistent in all vessels. Among MINOCA subtypes, no significant difference in average aIMR could be detected between patients with coronary cause (33.2 ± 6.6), takotsubo cardiomyopathy (29.2 ± 6.9), infiltrative or inflammatory cardiomyopathy (28.1 ± 6.8) or unclear cause (30.6 ± 8.5; p = 0.412). Interestingly, aIMR was significantly elevated in the coronary vessel supplying the diseased myocardium compared with other vessels (31.9 ± 11.4 vs. 27.8 ± 8.2, p = 0.049).

CONCLUSION

Coronary microvascular dysfunction is a hallmark of all MINOCA subtypes. This study adds to the pathophysiological understanding of MINOCA and sheds light into the role of CMD in MINOCA.

Unveiling the Enigma: Exploring the Intricate Link Between Coronary Microvascular Dysfunction and Takotsubo Cardiomyopathy

This review article delves into the intricate and evolving relationship between coronary microvascular dysfunction (CMD) and takotsubo cardiomyopathy (TCM), two intriguing cardiovascular conditions increasingly recognised for their potential interplay. We examine their characteristics, shared pathophysiological mechanisms, diagnostic challenges, and management strategies. Emerging evidence suggests a link between microvascular dysfunction and the development of TCM, leading to a deeper exploration of their connection. Accurate diagnosis of both conditions becomes essential, as microvascular dysfunction may modify TCM outcomes. We underscore the significance of understanding this connection for improved patient care, emphasising the need for tailored interventions when CMD and TCM coexist. Collaborative research and heightened clinical awareness are advocated to advance our comprehension of this relationship. Through interdisciplinary efforts, we aim to refine diagnostic precision, develop targeted therapies, and enhance patient outcomes in cardiovascular medicine.

In-Hospital Heart Failure in Patients With Takotsubo Cardiomyopathy Due to Coronary Artery Disease: An Artificial Intelligence and Optical Coherence Tomography Study

BACKGROUND

Takotsubo syndrome (TTS) is often associated with symptoms of heart failure (HF) during the acute phase of the disease. 3-dimensional optical coherence tomography (OCT) may be used to assess the extent of angiographically silent underlying coronary artery disease (CAD). This study aims to use an artificial intelligence algorithm to analyze OCT findings and to determine whether the presence of pre-existing CAD predisposes TTS patients to present HF at admission.

METHODS

This is an observational and retrospective study that enrolled TTS patients who underwent coronary angiography and OCT examination of left anterior descending (LAD) coronary artery. Plaque characterization was automatically analyzed via an artificial intelligence model from OCT images. An angiography-derived index of microcirculatory resistance (IMRangio) using the optic flow ratio (OFR) was calculated to assess its correlation with plaque volumes.

RESULTS

Thirty-seven patients were included (94.6 % women) with a median age of 82.0 years. Ten patients (27 %) showed some degree of HF at admission. Sixty-seven coronary non-obstructive plaques were analyzed. Tissue compositional analysis showed that patients with HF had an increased overall plaque volume (79.0 mm³ vs 28.6 mm³; p = 0.011) and longer plaque lesion length (12.8 mm vs 7.2 mm; p = 0.006). Patients with HF also showed an increased percentage of lipidic and calcified plaque tissue (26.4 % vs 13.4 %; p = 0.019 and 4.5 % vs 0.0 %; p = 0.001, respectively). A moderate positive correlation was found between global overall plaque volume and IMRangio.

CONCLUSION

Increased overall plaque volume was associated with the development of HF during the acute phase of TTS, suggesting that the presence of angiographically silent underlying CAD may play a prognostic role in these patients.

Angiography-derived index of microvascular resistance in takotsubo syndrome

Coronary microvascular dysfunction (CMD) has been proposed as a key driver in the etiopathogenesis of Takotsubo syndrome (TTS), likely related to an "adrenergic storm" upon a susceptible microvascular circulation. The aim of our manuscript was to assess CMD in patients with TTS through the computation of the angiography-derived index of microcirculatory resistance (IMR) and its correlation with clinical presentation. Coronary angiograms of 41 consecutive TTS patients were retrospectively analyzed to derive angiography-based indices of CMD. Three indices (NH-IMRangio, AngioIMR and A-IMR) were calculated based on quantitative flow ratio. CMD was defined as an IMRangio value ≥ 25 units. The correlation between CMD and clinical presentation was then assessed. Median age was 76 years, 85.7% were women and mean left ventricular ejection fraction (LVEF) at first echocardiogram was 41.2%. Angiography-derived IMR was higher in left anterior descending artery (LAD) than circumflex and right coronary artery with either NH-IMRangio (53.9 ± 19.8 vs 35.8 ± 15.4 vs 40.8 ± 18.5, p-value < 0.001), AngioIMR (47.2 ± 17.3 vs 31.8 ± 12.2 vs 37.3 ± 13.7, p-value < 0.001) or A-IMR (52.7 ± 19 vs 36.1 ± 14.1 vs 41.8 ± 16.1, p-value < 0.001). All patients presented CMD with angiography-derived IMR ≥ 25 in at least one territory with each formula. Angiography-derived IMR in LAD territory was significantly higher in patients presenting with LVEF impairment (≤ 40%) than in those with preserved ventricular global function (NH-IMRangio: 59.3 ± 18.1 vs 46.3 ± 16.0 p-value = 0.030; AngioIMR: 52.9 ± 17.8 vs 41.4 ± 14.2, p-value = 0.037; A-IMR: 59.2 ± 18.6 vs 46.3 ± 17.0, p-value = 0.035). CMD assessed with angiography-derived IMR is a common finding in TTS and it is inversely correlated with LV function. The available formulas have a substantial superimposable diagnostic performance in assessing coronary microvascular function.

Incremental prognostic value of global longitudinal strain to the coronary microvascular resistances in Takotsubo patients

BACKGROUND

Global longitudinal strain (GLS) allows an accurate assessment of left ventricular function with prognostic value. We aimed to evaluate whether the assessment of GLS in the acute phase of Takotsubo syndrome (TTS) provides incremental prognostic value to the degree of impaired microvascular resistance (MR) in TTS patients at 1-year follow-up.

METHODS

We recruited patients admitted for TTS who underwent cardiac angiography and echocardiography from January 2017 to June 2020. Left anterior descending coronary artery non-hyperaemic angiography-derived index of microcirculatory resistance (LAD NH-IMRangio) was calculated. NT-proBNP, high-sensitive cardiac troponin T (hs-cTnT), left ventricular ejection fraction (LVEF) and GLS were measured at admission. Major adverse cardiac events (MACE) were defined as the composite of cardiovascular death, repeat hospitalizations for heart failure (HF) and acute myocardial infarctions.

RESULTS

67 patients had both GLS and NH-IMRangio available and were included in the study. Median age was 75.2 years and 88% were women. Rate of MACE at 1-year was 13.4%. Kaplan-Meier curves showed higher rates of MACE at 1-year in patients with both higher LAD NH-IMRangio and GLS values compared with those with higher LAD NH-IMRangio and lower GLS values (33.3% vs. 11.1%; p = 0.049). NT-proBNP levels at admission and the recovery of LVEF were correlated with GLS values while MR and hs-cTnT were not.

CONCLUSION

GLS provides incremental prognostic value to the degree of impaired MR in TTS patients. The combination of a poorer GLS with a higher degree of impaired MR was associated with a higher rate of MACE in these patients.

Prognostic value of coronary microvascular dysfunction assessed by coronary angiography-derived index of microcirculatory resistance in diabetic patients with chronic coronary syndrome

Background

Coronary microvascular dysfunction (CMD) is common and is associated with unfavorable cardiovascular events in patients with diabetes mellitus (DM). Coronary angiography-derived index of microcirculatory resistance (caIMR) is a recently developed wire- and hyperemic agent-free method to assess CMD. We aimed to investigate the prognostic impact of CMD assessed by caIMR on clinical outcomes in patients with DM and chronic coronary syndrome (CCS).

Methods

CCS patients who underwent coronary angiography between June 2015 to May 2018 were included. Coronary microvascular function was measured by caIMR, and CMD was defined as caIMR ≥ 25U. The primary endpoint was major adverse cardiac events (MACE). Kaplan-Meier analysis and Cox proportional hazards models were used to assess the relationship between caIMR and the risk of MACE.

Results

Of 290 CCS patients, 102 patients had DM. Compared with non-diabetic patients, CMD (caIMR ≥ 25U) was higher among DM patients (57.8% vs. 38.3%; p = 0.001). During a mean 35 months follow-up, 40 MACE had occurred. Patients with caIMR ≥ 25 had a higher rate of MACE than patients with caIMR < 25 (20.6% vs. 8.2%, p = 0.002). Of these, the MACE rate was higher among DM patients with caIMR ≥ 25 than those with caIMR < 25 (33.9% vs. 14.0%; p = 0.022). In multivariable Cox analysis, caIMR ≥ 25 was independently associated with MACE in the DM patients but not in non-DM patients (HR, 2.760; 95% CI, 1.066–7.146; P = 0.036).

Conclusion

CMD assessed by caIMR was common and is an independent predictor of MACE among diabetic patients with CCS. This finding potentially enables a triage of higher-risk patients to more intensive therapy.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12933-022-01653-y.

Role of sex on the efficacy of pharmacological and non-pharmacological treatment of heart failure with reduced ejection fraction: A systematic review

Background

Heart Failure (HF) is a growing epidemic with a similar prevalence in men and women. However, women have historically been underrepresented in clinical trials, leading to uneven evidence regarding the benefit of guideline-directed medical therapy (GDMT). This review aims to outline the sex differences in the efficacy of pharmacological and non-pharmacological treatment of HF with reduced ejection fraction (HFrEF).

Methods and results

We conducted a systematic review via Medline from inception to 31 January 2022, including all randomized clinical trials published in English including adult patients suffering HFrEF that reported data on the efficacy of each drug. Baseline clinical characteristics, primary outcomes, and sex-specific effects are summarized in tables. The systemic review has been conducted in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-analyses (PRISMA) statement. In total, 29 articles were included in the systematic review. We observed that the proportion of women enrolled in clinical trials was generally low, the absence of a prespecified analysis of efficacy by sex was frequent, and the level of quality of evidence on the efficacy of GDMT and implantable cardioverter defibrillator (ICD) or cardiac resynchronization therapy (CRT-) in women was relatively poor.

Conclusions

Sex influences the response to treatment of patients suffering from HFrEF. All the results from the landmark randomized clinical trials are based on study populations composed mainly of men. Further studies specifically designed considering sex differences are warranted to elucidate if GDMT and new devices are equally effective in both sexes.

Plasma brain natriuretic peptide, platelet parameters, and cardiopulmonary function in chronic obstructive pulmonary disease

BACKGROUND

Chronic obstructive pulmonary disease (COPD) is a chronic respiratory disease with worldwide occurrence and high disability and mortality rate. It occurs mostly in the elderly population with pulmonary heart disease, type II respiratory failure, and other serious complications.

AIM

To investigate the correlation of plasma brain natriuretic peptide (BNP) and platelet parameters with cardiac function and pulmonary hypertension in patients with COPD and pulmonary heart disease.

METHODS

From June 2016 to June 2019, 52 patients with COPD-pulmonary heart disease (pulmonary heart disease group), 30 patients with COPD (COPD group), and 30 healthy individuals (control group) in our hospital were enrolled in the study. The pulmonary heart disease group was further divided into subgroups according to cardiac function classification and pulmonary artery pressure. Plasma BNP and platelet parameters were estimated and compared among each group and subgroup. The correlation of plasma BNP and platelet parameters with cardiac function classification and pulmonary artery pressure was then analyzed.

RESULTS

In the pulmonary heart disease group, the COPD group, and the control group, the levels of plasma BNP, platelet distribution width (PDW), and mean platelet volume (MPV) showed a decreasing trend (P < 0.05), while an increasing trend was found in platelet count (PLT) and plateletcrit (PCT) levels among the three groups (P < 0.05). In the pulmonary hypertension mild, moderate, and severe subgroups, the levels of plasma BNP, PDW, and MPV showed an increasing trend (P < 0.05), while a decreasing trend was observed in PLT levels (P < 0.05); however, PCT levels showed no significant difference among the three subgroups (P > 0.05). In the cardiac function grade I, II, III, and IV subgroups, the levels of plasma BNP, PDW, and MPV showed an increasing trend (P < 0.05), while a decreasing trend was noted in PLT and PCT levels among the four subgroups (P < 0.05). Correlation analysis showed that the levels of plasma BNP, PDW, and MPV in patients with pulmonary heart disease were positively correlated with their pulmonary artery pressure (P < 0.05), while PLT was negatively correlated with their pulmonary artery pressure (P < 0.05). Moreover, plasma BNP, PDW, and MPV levels were positively correlated with cardiac function grade (P < 0.05) of these patients, while PLT and PCT levels were negatively correlated with their cardiac function grade (P < 0.05).

CONCLUSION

Plasma BNP and PLT parameters are significantly correlated with the cardiac function and pulmonary hypertension in patients with COPD and pulmonary heart disease, indicating that these parameters have high clinical relevance in reflecting the health condition of these patients and for guiding their treatment.