An Urgent Call for Studies That Address the Cardiovascular Consequences of Legalization of Marijuana

In about a decade, half of the United States has legalized marijuana for recreational use. The drug has been associated with acute myocardial infarction, acute stroke, congestive heart failure, and various cardiac arrythmias. Data have shown that legalization of the drug led to an increase of its use as well as an increase in tetra hydro cannabinoid positive tests in patients admitted to emergency departments. In Colorado, one of the earlier states to implement legalization, there was an increase in traffic accidents, suicide rates, and even total mortality. However, there is a paucity of data on the effect of marijuana legalization on various cardiovascular events. It is prudent to have well-designed studies with enough power to provide consumers and health care providers the information they need to decide whether the risks of marijuana, especially on the cardiovascular front, are worth the "high" or potential benefits that have been described for other medical conditions.

Impact of symptom-to-reperfusion-time on transmural infarct extent and left ventricular strain in patients with ST-segment elevation myocardial infarction: a 3D view on the wavefront phenomenon

AIMS

We examined the association between the symptom-to-reperfusion-time and cardiovascular magnetic resonance (CMR)-derived global strain parameters and transmural infarct extent in ST-segment elevation myocardial infarction (STEMI) patients.

METHODS AND RESULTS

The study included 108 STEMI patients who underwent successful primary percutaneous coronary intervention (PPCI). Patients were categorized according to the median symptom-to-reperfusion-time: shorter (<160 min, n = 54) and longer times (>160 min, n = 54). CMR was performed 2-7 days after PPCI and at 1 month. CMR cine imaging was performed for functional assessment and late gadolinium enhancement to evaluate transmural infarct extent. Myocardial feature-tracking was used for strain analysis. Groups were comparable in relation to incidence of LAD disease and pre- and post-PPCI thrombolysis in myocardial infarction (TIMI) flow grades. The mean transmural extent score at follow-up was lower in patients with shorter reperfusion time (P < 0.01). Both baseline and follow-up maximum transmural extent scores were smaller in patients with shorter reperfusion time (P = 0.03 for both). Patients with shorter reperfusion time had more favourable global left ventricular (LV) circumferential strain (baseline, P = 0.049; follow-up, P = 0.01) and radial strain (baseline, P = 0.047; follow-up, P < 0.01), whilst LV longitudinal strain appeared comparable for both baseline and follow-up (P > 0.05 for both). In multi-variable regression analysis including all three strain directions, baseline LV circumferential strain was independently associated with the mean transmural extent score at follow-up (β=1.89, P < 0.001).

CONCLUSION

In STEMI patients, time-to-reperfusion was significantly associated with smaller transmural extent of infarction and better LV circumferential and radial strain. Moreover, infarct transmurality and residual LV circumferential strain are closely linked.

Association of the COVID-19 Pandemic on Treatment Times for ST-Elevation Myocardial Infarction: Observations from the Los Angeles County Regional System

Previous studies have documented longer treatment times and worse outcomes for patients with ST-elevation myocardial infarction (STEMI) who underwent primary percutaneous coronary intervention (PCI) during the COVID-19 pandemic. The objective of the present study was to evaluate the impact of the COVID-19 pandemic on treatment times and outcomes for patients with STEMI who underwent primary PCI within a regional system of care. This was a retrospective study using data from the Los Angeles County Emergency Medical Services Agency. Data on the emergency medical service activations were abstracted for patients with STEMI from March 19, 2020 to January 31, 2021, during the COVID-19 pandemic and for the same interval the previous year. All adult patients (≥18 years) with STEMI who underwent emergent coronary angiography were included. The primary end point was the first medical contact (FMC) to device time. The secondary end points included treatment time intervals, vascular complications, need for emergent coronary artery bypass surgery, length of hospital stay, and in-hospital mortality. During the study period, 3,017 patients underwent coronary angiography for STEMI, 1,893 patients pre-COVID-19 and 1,124 patients during COVID-19 (40% lower). A total of 2,334 patients (77%) underwent PCI. During the COVID-19 period, rates of PCI were significantly lower compared with the control period (75.1% vs 78.7%, p = 0.02). FMC to device time was shorter during the COVID-19 period compared with the control period (median 77.0 vs 81.0 minutes, p = 0.004). For patients with STEMI complicated by out-of-hospital cardiac arrest, FMC to device time was similar during the COVID-19 period compared with the control period (median 95.0 [33.0] vs 100.0 [40.0] minutes, p = 0.34). Vascular complications, the need for emergent bypass surgery, length of hospital stay, and in-hospital mortality were similar between the periods. In conclusion, in this large regional system of care, we found a relatively small but significant decrease in treatment times, yet overall, similar clinical outcomes for patients with STEMI who underwent primary PCI and were treated during the COVID-19 period compared with a control period. These findings suggest that mature cardiac systems of care were able to maintain efficient care despite the challenges of the COVID-19 pandemic.

Effects of Electronic Cigarette Vaping on Cardiac and Vascular Function, and Post-myocardial Infarction Remodeling in Rats

The effect of electronic cigarette (E-cig) vaping on cardiac and vascular function during the healing phase of myocardial infarction (MI), and post-MI remodeling was investigated. Sprague Dawley rats were subjected to left coronary artery ligation to induce MI. One week later, rats were randomized to receive either 12 weeks of exposure to purified air (n = 37) or E-cig vapor (15 mg/ml of nicotine) (n = 32). At 12 weeks, cardiac and vascular function, and post-MI remodeling were assessed. Baseline blood flow in the femoral artery did not differ between groups, but peak reperfusion blood flow was blunted in the E-cig group (1.59 ± 0.15 ml/min) vs. the air group (2.11 ± 0.18 ml/min; p = 0.034). Femoral artery diameter after reperfusion was narrower in the E-cig group (0.54 ± 0.02 mm) compared to the air group (0.60 ± 0.02 mm; p = 0.023). Postmortem left ventricular (LV) volumes were similar in the E-cig (0.69 ± 0.04 ml) and air groups (0.73 ± 0.04 ml; p = NS); and myocardial infarct expansion index did not differ between groups (1.4 ± 0.1 in E-cig group versus 1.3 ± 0.1 in air group; p = NS). LV fractional shortening by echo did not differ between groups at 12 weeks (E-cig at 29 ± 2% and air at 27 ± 1%; p = NS). Exposure to E-cig during the healing phase of MI was associated with altered vascular function with reduced femoral artery blood flow and diameter at reperfusion, but not with worsened LV dilation or worsened cardiac function.

The association of tadalafil exposure with lower rates of major adverse cardiovascular events and mortality in a general population of men with erectile dysfunction

BACKGROUND

Tadalafil is a long-acting phosphodiesterase-5 inhibitor (PDE-5i) indicated for erectile dysfunction (ED).

HYPOTHESIS

Our hypothesis was that tadalafil will reduce the risk of major adverse cardiovascular events (MACE: composite of cardiovascular death, myocardial infarction, coronary revascularization, unstable angina, heart failure, stroke) and all-cause death in men with ED.

METHODS

A retrospective observational cohort study was conducted in a large US commercial insurance claims database in men with a diagnosis of ED without prior MACE within 1 year. The exposed group (n = 8156) had ≥1 claim for tadalafil; the unexposed group (n = 21 012) had no claims for any PDE-5i.

RESULTS

Primary outcome was MACE; secondary outcome was all-cause death. Groups were matched for cardiovascular risk factors, including preventive therapy. Over a mean follow-up of 37 months for the exposed group and 29 months for the unexposed group, adjusted rates of MACE were 19% lower in men exposed to tadalafil versus those unexposed to any PDE-5i (hazard ratio [HR] = 0.81; 95% confidence intervals [CI] = 0.70-0.94; p = .007). Tadalafil exposure was associated with lower adjusted rates of coronary revascularization (HR = 0.69; 95% CI = 0.52-0.90; p = .006); unstable angina (HR = 0.55; 95% CI = 0.37-0.81; p = .003); and cardiovascular-related mortality (HR = 0.45; CI = 0.22-0.93; p = .032). Overall mortality rate was 44% lower in men exposed to tadalafil (HR = 0.56; CI = 0.43-0.74; p < .001). Men in the highest quartile of tadalafil exposure had the lowest rates of MACE (HR: 0.40; 95% CI: 0.28-0.58; p < .001) compared to lowest exposure quartile.

CONCLUSION

In men with ED, exposure to tadalafil was associated with significant and clinically meaningful lower rates of MACE and overall mortality.

Princeton IV consensus guidelines: PDE5 inhibitors and cardiac health

BACKGROUND

In 1999, 1 year after the approval of the first oral phosphodiesterase type 5 (PDE5) inhibitor for the treatment of erectile dysfunction (ED), the first Princeton Consensus Conference was held to address the clinical management of men with ED who also had cardiovascular disease. These issues were readdressed in the second and third conferences. In the 13 years since the last Princeton Consensus Conference, the experience with PDE5 inhibitors is more robust, and recent new data have emerged regarding not only safety and drug-drug interactions, but also a potential cardioprotective effect of these drugs.

AIM

In March 2023, an interdisciplinary group of scientists and practitioners met for the fourth Princeton Consensus Guidelines at the Huntington Medical Research Institutes in Pasadena, California, to readdress the cardiovascular workup of men presenting with ED as well as the approach to treatment of ED in men with known cardiovascular disease.

METHOD

A series of lectures from experts in the field followed by Delphi-type discussions were developed to reach consensus.

OUTCOMES

Consensus was reached regarding a number of issues related to erectile dysfunction and the interaction with cardiovascular health and phosphodiesterase-5 inhibitors.

RESULTS

An algorithm based on recent recommendations of the American College of Cardiology and American Heart Association, including the use of computed tomography coronary artery calcium scoring, was integrated into the evaluation of men presenting with ED. Additionally, the issue of nitrate use was further considered in an algorithm regarding the treatment of ED patients with coronary artery disease. Other topics included the psychological effect of ED and the benefits of treating it; the mechanism of action of the PDE5 inhibitors; drug-drug interactions; optimizing use of a PDE5 inhibitors; rare adverse events; potential cardiovascular benefits observed in recent retrospective studies; adulteration of dietary supplements with PDE5 inhibitors; the pros and cons of over-the-counter PDE5 inhibitors; non-PDE5 inhibitor therapy for ED including restorative therapies such as stem cells, platelet-rich plasma, and shock therapy; other non-PDE5 inhibitor therapies, including injection therapy and penile prostheses; the issue of safety and effectiveness of PDE5 inhibitors in women; and recommendations for future studies in the field of sexual dysfunction and PDE5 inhibitor use were discussed.

CLINICAL IMPLICATIONS

Algorithms and tables were developed to help guide the clinician in dealing with the interaction of ED and cardiovascular risk and disease.

STRENGTHS AND LIMITATIONS

Strengths include the expertise of the participants and consensus recommendations. Limitations included that participants were from the United States only for this particular meeting.

CONCLUSION

The issue of the intersection between cardiovascular health and sexual health remains an important topic with new studies suggesting the cardiovascular safety of PDE5 inhibitors.

Choriocapillaris and Retinal Vascular Alterations in Presymptomatic Alzheimer's Disease

Purpose

To compare optical coherence tomography angiography (OCTA) retina metrics between cognitively healthy subjects with pathological versus normal cerebrospinal fluid (CSF) Aβ42/tau ratios.

Methods

Swept-source OCTA scans were collected using the Zeiss PLEX Elite 9000 and analyzed on 23 cognitively healthy (CH) subjects who had previously undergone CSF analysis. Thirteen subjects had a pathological Aβ42/tau (PAT) ratio of <2.7132, indicative of presymptomatic Alzheimer's disease (AD), and 10 had a normal Aβ42/tau (NAT) ratio of ≥2.7132. OCTA en face images of the superficial vascular complex (SVC) and deep vascular complex were binarized and skeletonized to quantify the perfusion density (PD), vessel length density (VLD), and fractal dimension (FrD). The foveal avascular zone (FAZ) area was calculated using the SVC slab. Choriocapillaris flow deficits (CCFDs) were computed from the en face OCTA slab of the CC. The above parameters were compared between CH-PATs and CH-NATs.

Results

Compared to CH-NATs, CH-PATs showed significantly decreased PD, VLD, and FrD in the SVC, with a significantly increased FAZ area and CCFDs.

Conclusions

Swept-source OCTA analysis of the SVC and CC suggests a significant vascular loss at the CH stage of pre-AD that might be an indicator of a neurodegenerative process initiated by the impaired clearance of Aβ42 in the blood vessel wall and by phosphorylated tau accumulation in the perivascular spaces, a process that most likely mirrors that in the brain. If confirmed in larger longitudinal studies, OCTA retinal and inner choroidal metrics may be important biomarkers for assessing presymptomatic AD.

Biomarkers - Part 1

BACKGROUND

The CSF amyloid to tau ratio can isolate cognitively healthy participants into normal Aβ42/tau (CH-NAT) or a pathological Aβ42/tau (CH-PAT) with a low or high risk of cognitive decline, respectively. We aim to determine if plasma Aβ42/tau ratios can differentiate CH-NAT from CH-PAT participants.

METHOD

Study participants (> 65 years of age) were recruited, and demographic, neurological, and neuropsychological data were obtained in an ongoing HMRI Brain Aging study. Overnight fasting plasma and CSF were collected within a month of examination, and the levels of Aβ38, Aβ40, Aβ42 (MSD 6E10 kit), and total tau were quantified using the MSD electrochemiluminescence platform. Differences in fluid biomarker levels and the plasma ratios (n = 55) and CSF ratios (Aβ42/Aβ40, n = 41, Aβ42/tau, n = 55) were determined using nonparametric student t-test and correlations using a Spearman test.

RESULT

Aβ40 and Aβ42 levels were higher (15-18-fold, and 10-14-fold, respectively), while tau levels are 8-13-fold higher in CSF than in plasma. Plasma and CSF Aβ40 were not distinct in CH-NAT compared with CH-PAT. In contrast, Aβ42 levels were 30.9% lower in CH-PAT (16.3 ± 18.3 pg/ml) compared with CH-NAT plasma (23.6 ± 26.4 pg/mL) (p < 0.05). CSF Aβ42 levels in CH-PAT (171.6 ± 124.6 pg/mL) were lower by 47.6% compared with CH-NAT (327.6 ± 182.6 pg/ml) (p < 0.0001). The Aβ42/Aβ40 ratio was significantly lower in both plasma and CSF (Table 1A). Similarly, the Aβ42/tau ratio was significantly lower in plasma and CSF (Table 1B). Individually, plasma levels of Aβ42 and tau did not correlate with CSF levels. However, the ratio of Aβ42 to total tau in plasma significantly correlated with the CSF ratios (Spearman r = 0.36, p = 0.0071). Finally, CSF Aβ42/Aβ40 ratio correlated with Aβ42/tau ratio for all samples, CH (n = 100) and MCI (n = 35) (Fig. 1).

CONCLUSION

While not as robust as CSF ratios, plasma Aβ42/Aβ40 and Aβ42/tau ratios can isolate cognitively healthy participants with lower risk from participants with a higher risk of cognitive decline. Thus, plasma represents a less invasive medium for the biomarker classification of aging participants.

Flavoring Agents in E-cigarette Liquids: A Comprehensive Analysis of Multiple Health Risks

The availability of a wide range of flavored e-cigarettes is one of the primary reasons for vaping initiation and persistent use among adolescents and young people. This plethora of flavors available on the market are crafted using different flavoring agents such as cinnamaldehyde, vanillin, benzaldehyde, ethyl maltol, menthol, and dimethylpyrazine. Recent studies have brought to light the potential risks associated with e-cigarette flavoring agents and their effects on various organ systems, both with and without nicotine. Research has demonstrated that flavoring agents can induce inflammation, endothelial dysfunction, epithelial barrier disruption, oxidative stress, DNA damage, electrophysiological alterations, immunomodulatory effects, and behavioral changes, even independently of nicotine. Notably, these negative outcomes adversely affect cardiovascular system by reducing cell viability, decreasing endothelial nitric oxide synthase, nitric oxide bioavailability, soluble guanylyl cyclase activity and cyclic guanosine monophosphate accumulation, impairing endothelial proliferation and tube formation, and altering vasoreactivity resulting in vascular dysfunction. In the heart, these agents decrease parasympathetic activity, induce depolarization of resting membrane potential, loss of rhythmicity, increase isovolumic relaxation time, and change in ventricular repolarization and ventricular tachyarrhythmias. It is found that the specific response elicited by flavoring agents in different organ systems varies depending on the flavor used, the concentration of the flavoring agent, and the duration of exposure. However, the literature on the effects of flavoring agents is currently limited, emphasizing the need for more preclinical and randomized clinical trials to gain a deeper understanding and provide further evidence of the harmful effects of flavored e-cigarette use. In summary, recent research suggests that flavoring agents themselves can have detrimental effects on the body. To fully comprehend these effects, additional preclinical and clinical studies are needed to explore the risks associated with flavored e-cigarette usage.

Instantaneous detection of acute myocardial infarction and ischaemia from a single carotid pressure waveform in rats

Aims

Myocardial infarction (MI) is one of the leading causes of death worldwide. It is well accepted that early diagnosis followed by early reperfusion therapy significantly increases the MI survival. Diagnosis of acute MI is traditionally based on the presence of chest pain and electrocardiogram (ECG) criteria. However, around 50% of the MIs are without chest pain, and ECG is neither completely specific nor definitive. Therefore, there is an unmet need for methods that allow detection of acute MI or ischaemia without using ECG. Our hypothesis is that a hybrid physics-based machine learning (ML) method can detect the occurrence of acute MI or ischaemia from a single carotid pressure waveform.

Methods and results

We used a standard occlusion/reperfusion rat model. Physics-based ML classifiers were developed using intrinsic frequency parameters extracted from carotid pressure waveforms. ML models were trained, validated, and generalized using data from 32 rats. The final ML models were tested on an external stratified blind dataset from additional 13 rats. When tested on blind data, the best ML model showed specificity = 0.92 and sensitivity = 0.92 for detecting acute MI. The best model's specificity and sensitivity for ischaemia detection were 0.85 and 0.92, respectively.

Conclusion

We demonstrated that a hybrid physics-based ML approach can detect the occurrence of acute MI and ischaemia from carotid pressure waveform in rats. Since carotid pressure waveforms can be measured non-invasively, this proof-of-concept pre-clinical study can potentially be expanded in future studies for non-invasive detection of MI or myocardial ischaemia.

Cardiac Effects of Phosphodiesterase-5 Inhibitors: Efficacy and Safety

The coexistence of cardiovascular disease and erectile dysfunction is widespread, possibly owing to underlying endothelial dysfunction in both diseases. Millions of patients with cardiovascular disease are prescribed phosphodiesterase-5 (PDE5) inhibitors for the management of erectile dysfunction. Although the role of PDE5 inhibitors in erectile dysfunction therapy is well established, their effects on the cardiovascular system are unclear. Preclinical studies investigating the effect of PDE5 inhibitors on ischemia-reperfusion injury, pressure overload-induced hypertrophy, and chemotoxicity suggested a possible clinical role for each of these medications; however, attempts to translate these findings to the bedside have resulted in mixed outcomes. In this review, we explore the biologic preclinical effects of PDE5 inhibitors in mediating cardioprotection. We then examine clinical trials investigating PDE5 inhibition in patients with heart failure, coronary artery disease, and ventricular arrhythmias and discuss why the studies likely have yet to show positive results and efficacy with PDE5 inhibition despite no safety concerns.

Invasive versus Conservative Management in Coronary Artery Disease

Background: In patients with ST-elevation myocardial infarction, immediate coronary angiography and intervention is the best practice, if an experienced laboratory is available. In non-Q-wave infarction most, but not all, studies suggest that early invasive strategy is superior to conservative management. Complete revascularization is preferred.Methods: A literature search regarding management of coronary artery disease was conducted in PubMed between January 1985 to January 2021. Articles published in English were reviewed, and those relevant were selected by both authors. Special focus was on the ISCHEMIA trial and related articles.Results: The utility of coronary angiography in patients with stable coronary artery disease is challenging. All patients should undergo optimal medical therapy. Patients with angina should not only receive approved anti-anginal agents but should also receive lifestyle modifications and pharmacologic therapy to control risk factors such as diabetes, hypertension, dyslipidemia, and smoking; and should consider organized physical activity programs. Low density lipoprotein should be reduced to 70 mg/dL or less. Non-invasive studies such as coronary computed tomography angiography (CCTA) are preferred. If expert CCTA is not available, then stress test, preferably with imaging, is recommended. If the results of CCTA show high risk, then coronary angiography and intervention are usually indicated. In patients with left main disease, left ventricular dysfunction, or symptoms of congestive heart failure, early invasive strategy is recommended. If none of these conditions exist, then initial medical therapy may be initiated, and invasive therapy should be utilized only if clinically indicated. In patients with chronic stable angina, continue with medical therapy and risk factor modification. If the frequency or severity of angina episodes change, coronary angiography and revascularization should be considered, as appropriate. In patients with significant renal dysfunction, angiogram may be indicated only if there is complete failure of medical therapy.Conclusion: Optimal medical therapy should be initially utilized in all patients. Early invasive management and revascularization should be utilized in patients with left ventricular dysfunction, congestive heart failure, and failure of medical therapy. A shared decision-making process should always be utilized.

Resting heart rate (variability) and cognition relationships reveal cognitively healthy individuals with pathological amyloid/tau ratio

Introduction

Resting heart rate (HR) and heart rate variability (HRV) have been linked with cognition in the general population and in older individuals. The knowledge of this aspect of heart-brain relationship is relatively absent in older individuals with early Alzheimer's disease (AD) pathology. This study explores relationships of the HR, HRV, and cognition in cognitively healthy individuals with pathological amyloid/tau ratio (CH-PATs) in cerebral spinal fluid (CSF) compared to those with normal ratio (CH-NATs).

Methods

We examined therelationshipsbetween1) resting HR and Mini-Mental State Examination (MMSE); 2) resting HR and brain processing during Stroop interference; and 3) resting vagally mediated HRV (vmHRV) and task switching performance.

Results

Our studies showed that compared to CH-NATs, those CH-PATs with higher resting HR presented with lower MMSE, and less brain activation during interference processing. In addition, resting vmHRV was significantly correlated with task switching accuracy in CH-NATs, but not in CH-PATs.

Discussion

Thesethreedifferenttestsindicatedysfunctionalheart-brainconnections in CH-PATs, suggesting a potential cardio-cerebral dysfunctional integration.

The connection between heart rate variability (HRV), neurological health, and cognition: A literature review

The heart and brain have bi-directional influences on each other, including autonomic regulation and hemodynamic connections. Heart rate variability (HRV) measures variation in beat-to-beat intervals. New findings about disorganized sinus rhythm (erratic rhythm, quantified as heart rate fragmentation, HRF) are discussed and suggest overestimation of autonomic activities in HRV changes, especially during aging or cardiovascular events. When excluding HRF, HRV is regulated via the central autonomic network (CAN). HRV acts as a proxy of autonomic activity and is associated with executive functions, decision-making, and emotional regulation in our health and wellbeing. Abnormal changes of HRV (e.g., decreased vagal functioning) are observed in various neurological conditions including mild cognitive impairments, dementia, mild traumatic brain injury, migraine, COVID-19, stroke, epilepsy, and psychological conditions (e.g., anxiety, stress, and schizophrenia). Efforts are needed to improve the dynamic and intriguing heart-brain interactions.

Effect of phosphodiesterase type 5 inhibitors on major adverse cardiovascular events and overall mortality in a large nationwide cohort of men with erectile dysfunction and cardiovascular risk factors: A retrospective, observational study based on healthcare claims and national death index data

BACKGROUND

Treatment with phosphodiesterase type 5 inhibitors (PDE-5is) is effective in treating erectile dysfunction (ED).

AIM

The objective of this study was to determine the effect of PDE-5is on the incidence of major adverse cardiovascular (CV) events (MACE; composite outcome of CV death, hospitalization for myocardial infarction, coronary revascularization, stroke, heart failure, and unstable angina pectoris) and overall mortality.

METHODS

A retrospective observational cohort study was conducted in a large US claims database in men with ≥1 diagnosis of ED without prior MACE within 1 year, from January 1, 2006, to October 31, 2020. The exposed group had ≥1 claim for PDE-5i and the unexposed group had no claims for PDE-5i, and the groups were matched up to 1:4 on baseline risk variables.

OUTCOME

The primary outcome was MACE and the secondary outcomes were overall mortality and individual components of MACE, determined by multivariable Cox proportional hazard modeling.

RESULTS

Matched plus multivariable analyses showed that MACE was lower by 13% in men exposed (n = 23 816) to PDE-5is (hazard ratio [HR] 0.87; 95% CI 0.79-0.95; P = .001) vs nonexposure (n = 48 682) over mean follow-up periods of 37 and 29 months, respectively, with lower incidence of coronary revascularization (HR 0.85; 95% CI 0.73-0.98; P = .029), heart failure (HR 0.83; 95% CI 0.72-0.97; P = .016), unstable angina (HR 0.78; 95% CI 0.64-0.96; P = .021), and CV death (HR 0.61; 95% CI 0.41-0.90; P = .014) with PDE-5i exposure. Phosphodiesterase type 5 inhibitor-exposed men had a 25% lower incidence of overall mortality (HR 0.75; 95% CI 0.65-0.87; P < .001). Men without coronary artery disease (CAD) but with CV risk factors at baseline showed a similar pattern. In the main study cohort, men in the highest quartile of PDE-5i exposure had the lowest incidence of MACE (HR 0.45; 95% CI 0.37-0.54; P < .001) and overall mortality (HR 0.51; 95% CI 0.37-0.71; P < .001) vs the lowest exposure quartile. In a subgroup with baseline type 2 diabetes (n = 6503), PDE-5i exposure was associated with a lower MACE risk (HR 0.79; 95% CI 0.64-0.97; P = .022).

CLINICAL IMPLICATIONS

PDE-5is may have cardioprotective effects.

STRENGTHS AND LIMITATIONS

Strengths are the large numbers of participants and consistency of the data; limitations include the retrospective nature of the study and unknown confounders.

CONCLUSIONS

In a large population of US men with ED, PDE-5i exposure was associated with lower incidence of MACE, CV death, and overall mortality risk compared to non-exposure. Risk reduction correlated with PDE-5i exposure level.

Effects of Electronic Cigarette Exposure on Myocardial Infarction and No-Reflow, and Cardiac Function in a Rat Model

PURPOSE

We investigated the effects of exposure to electronic cigarettes (E-cig) vapor on the sizes of the no-reflow and myocardial infarction regions, and cardiovascular function compared to exposure to purified air and standard cigarette smoke.

METHODS AND RESULTS

Sprague Dawley rats (both male and female, 6 weeks old) were successfully exposed to filtered air (n = 32), E-cig with nicotine (E-cig Nic⁺, n = 26), E-cig without nicotine (E-cig Nic^-, n = 26), or standard cigarette smoke (1R6F reference, n = 31). All rats were exposed to inhalation exposure for 8 weeks, prior to being subjected to 30 minutes of left coronary artery occlusion followed by 3 hours of reperfusion. Exposure to E-cig vapor with or without nicotine or exposure to standard cigarettes did not increase myocardial infarct size or worsen the no-reflow phenomenon. Exposure to E-cig Nic⁺ reduced the body weight gain, and increased the LV weight normalized to body weight and LV wall thickness and enhanced the collagen deposition within the LV wall. E-cig exposure led to cardiovascular dysfunction, such as reductions in cardiac output, LV positive and negative dp/dt, suggesting a reduction in contractility and relaxation, and increased systemic arterial resistance after coronary artery occlusion and reperfusion in rats compared to air or cigarette exposure.

CONCLUSIONS

E-cig exposure did not increase myocardial infarct size or worsen the no-reflow phenomenon, but induced deleterious changes in LV structure leading to cardiovascular dysfunction and increased systemic arterial resistance after coronary artery occlusion followed by reperfusion.

One Acute Exposure to E-Cigarette Smoke Using Various Heating Elements and Power Levels Induces Pulmonary Inflammation

Background

Electronic cigarettes (eC) may not be entirely benign. There is a lack of data on the effect of a single acute exposure of eC vapor using various heating sources and power settings upon lung injury. The purpose of this study was to determine if an acute exposure with eC vapor heated with different heating elements and power levels induced inflammatory changes in the lungs and heart.

Methods

Rats were exposed to pure air or received a single, 4-h exposure to eC vapor. The devices used either a stainless steel (SS) or nichrome (NC) heating element randomized to a low or high atomization power (45 versus 70 W). Rats were euthanized within 48 h of exposure.

Results

The eC groups showed accumulation of inflammatory cells in bronchial lumen, near the pleura, and within the alveolar spaces. The numbers of inflammatory cells per field in the lung parenchyma were significantly greater in the rats exposed to eC groups vs. the air group. There were significantly higher inflammatory gene expression changes in the lungs of animals assigned to 70 W power. We observed that eC vapor generated using burnt coils were toxic and could cause acute respiratory distress and myocarditis.

Conclusion

In conclusion, one 4-h exposure to eC vapor, in the absence of vitamin E oil or nicotine, significantly increased lung inflammation. Effects were seen after exposures to vapor generated using SS and NC heating elements at either high or low power. Vapor from devices with burnt coils can negatively affect the heart and lung.

The Correlation Between COVID-19 Hospitalizations and Emergency Medical Services Responses for Time-Sensitive Emergencies During the COVID-19 Pandemic

OBJECTIVE

COVID-19 has had significant secondary effects on health care systems, including effects on emergency medical services (EMS) responses for time-sensitive emergencies. We evaluated the correlation between COVID-19 hospitalizations and EMS responses for time-sensitive emergencies in a large EMS system.

METHODS

This was a retrospective study using data from the Los Angeles County EMS Agency. We abstracted data on EMS encounters for stroke, ST-elevation myocardial infarction (STEMI), out-of-hospital cardiac arrest (OHCA), and trauma from April 5, 2020 to March 6, 2021 and for the same time period in the preceding year. We also abstracted daily hospital admissions and censuses (total and intensive care unit [ICU]) for COVID-19 patients. We designated November 29, 2020 to February 27, 2021 as the period of surge. We calculated Spearman's correlations between the weekly averages of daily hospital admissions and census and EMS responses overall and for stroke, STEMI, OHCA, and trauma.

RESULTS

During the study period, there were 70,616 patients admitted for confirmed COVID-19, including 12,467 (17.7%) patients admitted to the ICU. EMS responded to 899,794 calls, including 9,944 (1.1%) responses for stroke, 3,325 (0.4%) for STEMI, 11,207 (1.2%) for OHCA, and 114,846 (12.8%) for trauma. There was a significant correlation between total hospital COVID-19 positive patient admissions and EMS responses for all time-sensitive emergencies, including a positive correlation with stroke (0.41), STEMI (0.37), OHCA (0.78), and overall EMS responses (0.37); and a negative correlation with EMS responses for trauma (-0.48). ICU COVID-19 positive patient admissions also correlated with increases in EMS responses for stroke (0.39), STEMI (0.39), and OHCA (0.81); and decreased for trauma (-0.53). Similar though slightly weaker correlations were found when evaluating inpatient census. During the period of surge, the correlation with overall EMS responses increased substantially (0.88) and was very strong with OHCA (0.95).

CONCLUSION

We found significant correlation between COVID-19 hospitalizations and the frequency of EMS responses for time-sensitive emergencies in this regional EMS system. EMS systems should consider the potential effects of this and future pandemics on EMS responses and prepare to meet non-pandemic resource needs during periods of surge, particularly for time-sensitive conditions.

Abstract 195: The Effect Of Phosphodiesterase-5 Inhibitors On Major Adverse Cardiovascular Events And Mortality In A Large Cohort Of Men With Erectile Dysfunction From A Nationwide Insurance Database: A Retrospective Study

Background: Phosphodiesterase type 5 inhibitor (PDE-5i) medications are effective in treating Erectile Dysfunction (ED) for tens of millions of men in the US and worldwide. The objective of this study was to determine the effect of PDE-5is on the incidence of major adverse cardiovascular events (MACE) (composite outcome of cardiovascular (CV) death, hospitalization for myocardial infarction, coronary revascularization, stroke, heart failure, or unstable angina pectoris) and all-cause death.

Methods: A retrospective observational cohort study was conducted in a large US commercial and Medicare insurance claims database in men with ≥1 diagnosis of ED without prior MACE hospitalization within 1 year from Jan 2006 to Oct 2020. The exposed group had ≥1 claim for PDE-5i; the unexposed group had no claims for PDE-5i and were matched 2:1 on baseline risk variables. The primary outcome was MACE and secondary outcome was all-cause death, determined by multivariate Cox proportional hazard modeling. Death data were obtained via National Death Index linkage.

Results: In this population, MACE was reduced by 13% in men exposed (n=23,816) to PDE-5is (hazard ratio (HR) 0.87; 95% Confidence Interval (CI) 0.79-0.95) vs. non-exposure (n=48,682) over mean follow up of 29 and 37 months, respectively. This was driven by reductions in coronary revascularization (HR 0.85; 0.73-0.98), heart failure (HR 0.83; 0.72-0.97), unstable angina (HR 0.78; 0.64-0.96), and CV death (HR 0.61; 0.41-0.90). PDE-5i-exposed men had a 25% reduction in all-cause death (HR 0.75; 0.65-0.87). Men without coronary artery disease but with CV risk factors at baseline showed a similar pattern. In the main study cohort, men in the highest quartile of PDE-5i exposure had the greatest reductions in MACE (HR 0.45; 0.37-0.54) and all-cause death (HR 0.51; 0.37-0.71) vs. the lowest exposure quartile. In a subgroup with baseline type 2 diabetes (n=6,305), PDE-5i exposure was associated with a lower MACE risk (HR 0.79; 0.64-0.97). All comparisons are significant at p<0.05.

Conclusions: In a large population of US men with ED, PDE-5i exposure was associated with reductions in MACE, CV death, and overall death risk compared to non-exposure. Risk reduction was positively correlated with PDE-5i exposure level.

Effects of OP2113 on Myocardial Infarct Size and No Reflow in a Rat Myocardial Ischemia/Reperfusion Model

PURPOSE

The present study was to determine whether OP2113 could limit myocardial infarction size and the no-reflow phenomenon in a rat myocardial ischemia/reperfusion model.

METHODS

Rat heart-isolated mitochondria (RHM) were used to investigate mitochondrial respiration and mitochondrial reactive oxygen species (mtROS) generation both in normal conditions and in ischemia/reperfusion-mimicking conditions (using high concentrations of succinate). Human skeletal muscle myoblasts (HSMM) in culture were used to investigate the cellular intermittent deprivation in energy substrates and oxygen as reported in ischemia/reperfusion conditions. In vivo, rats were anesthetized and subjected to 30 min of left coronary artery occlusion followed by 3 h of reperfusion. Rats were randomized to receive OP2113 as an intravenous infusion starting either 5 min prior to coronary artery occlusion (preventive), or 5 min prior to reperfusion (curative), or to receive vehicle starting 5 min prior to coronary artery occlusion. Infusions continued until the end of the study (3 h of reperfusion).

RESULTS

RHM treated with OP2113 showed a concentration-dependent reduction of succinate-induced mtROS generation. In HSMM cells, OP2113 treatment (5-10 μM) during 48H prevented the reduction in the steady-state level of ATP measured just after reperfusion injuries and decreased the mitochondrial affinity to oxygen. In vivo, myocardial infarct size, expressed as the percentage of the ischemic risk zone, was significantly lower in the OP2113-treated preventive group (44.5 ± 2.9%) versus that in the vehicle group (57.0 ± 3.6%; p < 0.05), with a non-significant trend toward a smaller infarct size in the curative group (50.8 ± 3.9%). The area of no reflow as a percentage of the risk zone was significantly smaller in both the OP2113-treated preventive (28.8 ± 2.4%; p = 0.026 vs vehicle) and curative groups (30.1 ± 2.3%; p = 0.04 vs vehicle) compared with the vehicle group (38.9 ± 3.1%). OP2113 was not associated with any hemodynamic changes.

CONCLUSIONS

These results suggest that OP2113 is a promising mitochondrial ROS-modulating agent to reduce no-reflow as well as to reduce myocardial infarct size, especially if it is on board early in the course of the infarction. It appears to have benefit on no-reflow even when administered relatively late in the course of ischemia.

Gabrb3 endothelial cell-specific knockout mice display abnormal blood flow, hypertension, and behavioral dysfunction

Our recent studies uncovered a novel GABA signaling pathway in embryonic forebrain endothelial cells that works independently from neuronal GABA signaling and revealed that disruptions in endothelial GABA_A receptor-GABA signaling from early embryonic stages can directly contribute to the origin of psychiatric disorders. In the GABA_A receptor β3 subunit endothelial cell conditional knockout (Gabrb3^ECKO) mice, the β3 subunit is deleted selectively from endothelial cells, therefore endothelial GABA_A receptors become inactivated and dysfunctional. There is a reduction in vessel densities and increased vessel morphology in the Gabrb3^ECKO telencephalon that persists in the adult neocortex. Gabrb3^ECKO mice show behavioral deficits such as impaired reciprocal social interactions, communication deficits, heightened anxiety, and depression. Here, we characterize the functional changes in Gabrb3^ECKO mice by evaluating cortical blood flow, examine the consequences of loss of endothelial Gabrb3 on cardiac tissue, and define more in-depth altered behaviors. Red blood cell velocity and blood flow were increased in the cortical microcirculation of the Gabrb3^ECKO mice. The Gabrb3^ECKO mice had a reduction in vessel densities in the heart, similar to the brain; exhibited wavy, myocardial fibers, with elongated 'worm-like' nuclei in their cardiac histology, and developed hypertension. Additional alterations in behavioral function were observed in the Gabrb3^ECKO mice such as increased spontaneous exploratory activity and rearing in an open field, reduced short term memory, decreased ambulatory activity in CLAMS testing, and altered prepulse inhibition to startle, an important biomarker of psychiatric diseases such as schizophrenia. Our results imply that vascular Gabrb3 is a key player in the brain as well as the heart, and its loss in both organs can lead to concurrent development of psychiatric and cardiac dysfunction.

Analysis of integrated clinical safety data of tadalafil in patients receiving concomitant antihypertensive medications

This pooled safety analysis assessed the incidence of hypotension‐related treatment‐emergent adverse events (TEAEs) and major adverse cardiovascular events (MACEs) in patients with concomitant use of tadalafil and antihypertensive medications. Data were pooled from seventy‐two Phase II–IV studies conducted on patients with a diagnosis of erectile dysfunction (ED) and/or benign prostate hyperplasia (BPH). Studies were categorized as either All placebo‐controlled studies or All studies. The incidences of hypotension‐related TEAEs and MACEs were analyzed by indication; by use of concomitant antihypertensive medications; and by the number of concomitant antihypertensive medications. A total of 15 030 and 22 825 patients were included in the analyses for All placebo‐controlled studies and All studies, respectively. In the All placebo‐controlled studies, the incidence of hypotension‐related TEAEs and MACEs was ranging between 0.6–1.5% and 0.0–1.0%, respectively, across all indications. Tadalafil was associated with an increase in hypotension‐related TEAEs only in the ED as‐needed group not receiving any concomitant antihypertensive medications (p‐value = .0070); no significant difference was reported between placebo and tadalafil in the groups of patients receiving ≥1 antihypertensive medication (p‐values ≥ .7386). Similarly, no significant differences (p‐values≥ .2238) were observed in the incidence of MACEs between tadalafil and placebo treatment groups, with or without concomitant use of antihypertensive medications, and across all indication categories. In the All studies group, results were similar. The pooled analysis showed no evidence that taking tadalafil alongside antihypertensive medications increases the risk of hypotension‐related TEAEs or MACEs compared with antihypertensive medications alone.

Scalability of cardiovascular intrinsic frequencies: Validations in preclinical models and non-invasive clinical studies

AIMS

Cardiovascular intrinsic frequencies (IFs) are associated with cardiovascular health and disease, separately capturing the systolic and diastolic information contained in a single (uncalibrated) arterial waveform. Previous clinical investigations related to IF have been restricted to studying chronic conditions, and hence its applicability for acute cardiovascular diseases has not been explored. Studies of cardiovascular complications such as acute myocardial infarction are difficult to perform in humans due to the high-risk and invasive nature of such procedures. Although they can be performed in preclinical (animal) models, the corresponding interpretation of IF measures and how they ultimately translate to humans is unknown. Hence, we studied the scalability of IF across species and sensor platforms.

MATERIALS AND METHODS

Scaled values of the two intrinsic frequencies ω1 and ω2 (corresponding to systolic and diastolic dynamics, respectively) were extracted from carotid waveforms acquired either non-invasively (via tonometry, Vivio or iPhone) in humans or invasively in rabbits and rats.

KEY FINDINGS

The scaled IF parameters for all species were found to fall within the same physiological ranges carrying similar statistical characteristics, even though body sizes and corresponding heart rates of the species were substantially different. Additionally, results demonstrated that all non-invasive sensor platforms were significantly correlated with each other for scaled IFs, suggesting that such analysis is device-agnostic and can be applied to upcoming wearable technologies.

SIGNIFICANCE

Ultimately, our results found that IFs are scalable across species, which is particularly valuable for the training of IF-based artificial intelligence systems using both preclinical and clinical data.

Post-Acute Sequelae of SARS-COVID-2 Syndrome: Just the Beginning

Viral diseases are some of the most common infections affecting humans. Despite the unpleasant symptoms, most people return to their normal lives without residual symptoms. Following the acute infectious phase of some viruses, however, in some individuals symptoms may linger to the extent they are unable to return to a normal lifestyle. Following coronavirus disease 2019 infection, significant numbers of patients continued to have symptoms that persisted for months after hospital discharge. Symptoms spanned many organ systems and were prominent in the pulmonary and cardiovascular systems. The exact mechanism is not clear. This group of patients represents a new challenge to our health care systems. An organized, multi-disciplinary approach and further research are warranted to be ready to deliver better care to these patients.

Task switching reveals abnormal brain-heart electrophysiological signatures in cognitively healthy individuals with abnormal CSF amyloid/tau, a pilot study

Electroencephalographic (EEG) alpha oscillations have been related to heart rate variability (HRV) and both change in Alzheimer’s disease (AD). We explored if task switching reveals altered alpha power and HRV in cognitively healthy individuals with AD pathology in cerebrospinal fluid (CSF) and whether HRV improves the AD pathology classification by alpha power alone.

We compared low and high alpha event-related desynchronization (ERD) and HRV parameters during task switch testing between two groups of cognitively healthy participants classified by CSF amyloid/tau ratio: normal (CH-NAT, n = 19) or pathological (CH-PAT, n = 27). For the task switching paradigm, participants were required to name the color or word for each colored word stimulus, with two sequential stimuli per trial. Trials include color (cC) or word (wW) repeats with low load repeating, and word (cW) or color switch (wC) for high load switching. HRV was assessed for RR interval, standard deviation of RR-intervals (SDNN) and root mean squared successive differences (RMSSD) in time domain, and low frequency (LF), high frequency (HF), and LF/HF ratio in frequency domain.

Results showed that CH-PATs compared to CH-NATs presented: 1) increased (less negative) low alpha ERD during low load repeat trials and lower word switch cost (low alpha: p = 0.008, Cohen’s d = −0.83, 95% confidence interval −1.44 to −0.22, and high alpha: p = 0.019, Cohen’s d = −0.73, 95% confidence interval −1.34 to −0.13); 2) decreasing HRV from rest to task, suggesting hyper-activated sympatho-vagal responses. 3) CH-PATs classification by alpha ERD was improved by supplementing HRV signatures, supporting a potentially compromised brain-heart interoceptive regulation in CH-PATs. Further experiments are needed to validate these findings for clinical significance.

Cardiac MRI to Visualize Myocardial Damage after ST-Segment Elevation Myocardial Infarction: A Review of Its Histologic Validation

Cardiac MRI is a noninvasive diagnostic tool using nonionizing radiation that is widely used in patients with ST-segment elevation myocardial infarction (STEMI). Cardiac MRI depicts different prognosticating components of myocardial damage such as edema, intramyocardial hemorrhage (IMH), microvascular obstruction (MVO), and fibrosis. But how do cardiac MRI findings correlate to histologic findings? Shortly after STEMI, T2-weighted imaging and T2* mapping cardiac MRI depict, respectively, edema and IMH. The acute infarct size can be determined with late gadolinium enhancement (LGE) cardiac MRI. T2-weighted MRI should not be used for area-at-risk delineation because T2 values change dynamically over the first few days after STEMI and the severity of T2 abnormalities can be modulated with treatment. Furthermore, LGE cardiac MRI is the most accurate method to visualize MVO, which is characterized by hemorrhage, microvascular injury, and necrosis in histologic samples. In the chronic setting post-STEMI, LGE cardiac MRI is best used to detect replacement fibrosis (ie, final infarct size after injury healing). Finally, native T1 mapping has recently emerged as a contrast material-free method to measure infarct size that, however, remains inferior to LGE cardiac MRI. Especially LGE cardiac MRI-defined infarct size and the presence and extent of MVO may be used to monitor the effect of new therapeutic interventions in the treatment of reperfusion injury and infarct size reduction. © RSNA, 2021 Online supplemental material is available for this article.

Emergency Medical Services Responses to Out-of-Hospital Cardiac Arrest and Suspected ST-Segment-Elevation Myocardial Infarction During the COVID-19 Pandemic in Los Angeles County

Background Public health emergencies may significantly impact emergency medical services responses to cardiovascular emergencies. We compared emergency medical services responses to out-of-hospital cardiac arrest (OHCA) and ST-segment‒elevation myocardial infarction (STEMI) during the 2020 COVID-19 pandemic to 2018 to 2019 and evaluated the impact of California's March 19, 2020 stay-at-home order. Methods and Results We conducted a population-based cross-sectional study using Los Angeles County emergency medical services registry data for adult patients with paramedic provider impression (PI) of OHCA or STEMI from February through May in 2018 to 2020. After March 19, 2020, weekly counts for PI-OHCA were higher (173 versus 135; incidence rate ratios, 1.28; 95% CI, 1.19‒1.37; P<0.001) while PI-STEMI were lower (57 versus 65; incidence rate ratios, 0.87; 95% CI, 0.78‒0.97; P=0.02) compared with 2018 and 2019. After adjusting for seasonal variation in PI-OHCA and decreased PI-STEMI, the increase in PI-OHCA observed after March 19, 2020 remained significant (P=0.02). The proportion of PI-OHCA who received defibrillation (16% versus 23%; risk difference [RD], -6.91%; 95% CI, -9.55% to -4.26%; P<0.001) and had return of spontaneous circulation (17% versus 29%; RD, -11.98%; 95% CI, -14.76% to -9.18%; P<0.001) were lower after March 19 in 2020 compared with 2018 and 2019. There was also a significant increase in dead on arrival emergency medical services responses in 2020 compared with 2018 and 2019, starting around the time of the stay-at-home order (P<0.001). Conclusions Paramedics in Los Angeles County, CA responded to increased PI-OHCA and decreased PI-STEMI following the stay-at-home order. The increased PI-OHCA was not fully explained by the reduction in PI-STEMI. Field defibrillation and return of spontaneous circulation were lower. It is critical that public health messaging stress that emergency care should not be delayed.

Cardiovascular Health and Disease in the Context of COVID-19

First documented in China in early December 2019, the novel severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) spread rapidly and continues to test the strength of healthcare systems and public health programs all over the world. Underlying cardiovascular disease has been recognized as a risk factor for coronavirus disease 2019 (COVID-19)-related morbidity and mortality since the early days of the pandemic. In addition, evidence demonstrates cardiac and endothelial damage in somewhere between one-third and three-quarters of individuals with COVID-19, regardless of symptom severity. This damage is thought to be mediated by direct viral infection, immunopathology and hypoxemia with the additional possibility of exacerbation via medication-induced cardiotoxicity. Clinically, the cardiovascular consequences of COVID-19 may present as myocarditis with or without arrhythmia, endothelial dysfunction and thrombosis, acute coronary syndromes and heart failure. Presentation can vary widely and may or may not be typical of the condition in an individual without COVID-19. There is evidence to support the prognostic utility of cardiac biomarkers (e.g., cardiac troponin) and imaging studies (e.g., echocardiography, cardiac magnetic resonance imaging) in the context of COVID-19 and building evidence suggests that cardiovascular screening may be warranted even among those with asymptomatic or mild infection and those without traditional cardiovascular risk factors. In addition, evidence suggests the potential for long-term cardiovascular consequences for those who recover from COVID-19 with implications for the field of cardiology long into the future. Even among those without COVID-19, disruption of infrastructure and changes in human behavior as a result of the pandemic also have an upstream role in cardiovascular outcomes, which have already been documented in multiple locations. This review summarizes what is currently known regarding the pathogenic mechanisms of COVID-19-related cardiovascular injury and describes clinical cardiovascular presentations, prognostic indicators, recommendations for screening and treatment, and long-term cardiovascular consequences of infection. Ultimately, medical personnel must be vigilant in their attention to possible cardiovascular symptoms, take appropriate steps for clinical diagnosis and be prepared for long-term ramifications of myocardial injury sustained as a result of COVID-19.

E-Cigarettes and Cardiopulmonary Health

E-cigarettes have surged in popularity over the last few years, particularly among youth and young adults. These battery-powered devices aerosolize e-liquids, comprised of propylene glycol and vegetable glycerin, typically with nicotine, flavors, and stabilizers/humectants. Although the use of combustible cigarettes is associated with several adverse health effects including multiple pulmonary and cardiovascular diseases, the effects of e-cigarettes on both short- and long-term health have only begun to be investigated. Given the recent increase in the popularity of e-cigarettes, there is an urgent need for studies to address their potential adverse health effects, particularly as many researchers have suggested that e-cigarettes may pose less of a health risk than traditional combustible cigarettes and should be used as nicotine replacements. This report is prepared for clinicians, researchers, and other health care providers to provide the current state of knowledge on how e-cigarette use might affect cardiopulmonary health, along with research gaps to be addressed in future studies.

Viral myocarditis: 1917-2020: From the Influenza A to the COVID-19 pandemics

Myocarditis is common during viral infection with cases described as early as the influenza pandemic of 1917, and the current COVID-19 pandemic is no exception. The hallmark is elevated troponin, which occurs in 36% of COVID patients, with electrocardiogram, echocardiogram, and cardiac magnetic resonance being valuable tools to assist in diagnosis. Cardiac inflammation may occur secondary to direct cardiac invasion with the virus, or to intense cytokine storm, often encountered during the course of the disease. Angiotensin converting enzyme inhibitors, angiotensin receptor blockers, and judicious use of beta-blockers are beneficial in management of myocarditis. Corticosteroids may be avoided during the very early phase of viral replication, but can be of clear benefit in hospitalized, critically ill patients. Statins are beneficial to shorten the course of the disease and may decrease mortality.

Acute administration of nicotine induces transient elevation of blood pressure and increases myocardial infarct size in rats

Aims

We investigated the acute effects of nicotine on myocardial infarct size, no reflow, hemodynamics and cardiac function in an acute myocardial ischemia and reperfusion infarction rat model.

Main methods

Female Sprague-Dawley rats (n = 23/group) received an intravenous loading dose of nicotine at 2.0 μg/kg/min or saline control for 30 min before starting coronary artery occlusion, then followed by a maintenance dose 0.35 μg/kg/min of nicotine to the end of 30 min occlusion and 3 h reperfusion.

Key findings

At baseline, there was no difference in systolic blood pressure (BP in mmHg) (nicotine, 69.0 ± 2.7; control, 69.3 ± 4.4; p = NS) or diastolic BP (nicotine, 45.7 ± 3.2; control, 48.2 ± 4.2; p = NS) between groups. Nicotine administration initially increased systolic BP (nicotine, 97.0 ± 8.6; control, 69.2 ± 3.3, p < 0.0001) and diastolic BP (nicotine, 65.6 ± 6.4; control, 47.4 ± 3.1, p = 0.0003) at 10 min after starting injection of the loading dose; BP dropped to control levels in both groups at 30 min. During occlusion and reperfusion, the BP and heart rate were not altered by nicotine. Nicotine significantly increased myocardial infarct size as a percentage of the ischemic risk zone compared to the controls (nicotine, 54.9 ± 1.9; control, 48.6 ± 2.7, p < 0.05), but nicotine did not affect the no-reflow size and heart function.

Significance

While acute nicotine only transiently elevated blood pressure, it did not affect hemodynamic parameters during coronary artery occlusion. Nicotine increased myocardial infarct size, suggesting that the increase in infarct size was not simply due to an increase in oxygen demand due to altered afterload, heart rate, or contractility, but may have been due to a more direct effect on the myocardium.

Medical Marijuana, Recreational Cannabis, and Cardiovascular Health: A Scientific Statement From the American Heart Association

Cannabis, or marijuana, has potential therapeutic and medicinal properties related to multiple compounds, particularly Δ-9-tetrahydrocannabinol and cannabidiol. Over the past 25 years, attitudes toward cannabis have evolved rapidly, with expanding legalization of medical and recreational use at the state level in the United States and recreational use nationally in Canada and Uruguay. As a result, the consumption of cannabis products is increasing considerably, particularly among youth. Our understanding of the safety and efficacy of cannabis has been limited by decades of worldwide illegality and continues to be limited in the United States by the ongoing classification of cannabis as a Schedule 1 controlled substance. These shifts in cannabis use require clinicians to understand conflicting laws, health implications, and therapeutic possibilities. Cannabis may have therapeutic benefits, but few are cardiovascular in nature. Conversely, many of the concerning health implications of cannabis include cardiovascular diseases, although they may be mediated by mechanisms of delivery. This statement critically reviews the use of medicinal and recreational cannabis from a clinical but also a policy and public health perspective by evaluating its safety and efficacy profile, particularly in relationship to cardiovascular health.

E-cigarette or Vaping Product Use-Associated Lung Injury Produced in an Animal Model From Electronic Cigarette Vapor Exposure Without Tetrahydrocannabinol or Vitamin E Oil

E-cigarette or vaping product use-associated lung injury was recognized in the United States in the summer of 2019 and is typified by acute respiratory distress, shortness of breath, chest pain, cough, and fever, associated with vaping. It can mimic many of the manifestations of coronavirus disease 2019 (COVID-19). Some investigators have suggested that E-cigarette or vaping product use-associated lung injury was due to tetrahydrocannabinol or vitamin E acetate oil mixed with the electronic cigarette liquid. In experimental rodent studies initially designed to study the effect of electronic cigarette use on the cardiovascular system, we observed an E-cigarette or vaping product use-associated lung injury-like condition that occurred acutely after use of a nichrome heating element at high power, without the use of tetrahydrocannabinol, vitamin E, or nicotine. Lung lesions included thickening of the alveolar wall with foci of inflammation, red blood cell congestion, obliteration of alveolar spaces, and pneumonitis in some cases; bronchi showed accumulation of fibrin, inflammatory cells, and mucus plugs. Electronic cigarette users should be cautioned about the potential danger of operating electronic cigarette units at high settings; the possibility that certain heating elements may be deleterious; and that E-cigarette or vaping product use-associated lung injury may not be dependent upon tetrahydrocannabinol, vitamin E, or nicotine.

The association of nadir CD4-T cell count and endothelial dysfunction in a healthy HIV cohort without major cardiovascular risk factors

Objectives:

HIV-infected population may have increased risk of cardiovascular disease. The prevalence of traditional cardiovascular disease risk factors such as hypertension, diabetes and dyslipidemia in HIV-infected individuals has made it difficult to assess the direct effects of HIV and immune factors on endothelial dysfunction and associated increased risk of atherosclerosis. The purpose of this study was to investigate indicators of endothelial dysfunction in an HIV cohort without hypertension and diabetes.

Methods:

We studied 19 HIV-infected patients between the ages of 25–76 years old with effectively suppressed viral load and without diagnosis of hypertension or diabetes. Endothelial function was measured by digital thermal monitoring of vascular reactivity using the VENDYS technique. Endothelial function was reported as vascular reactivity index. Systolic blood pressure and diastolic blood pressure at the time of VENDYS test were measured and latest lipid panels were recorded. The association between vascular reactivity index and CD4-T cells count, different antiretroviral therapy types (non-nucleoside reverse transcriptase, nucleoside reverse transcriptase, protease inhibitors, integrase inhibitors), vitamins use, systolic blood pressure, diastolic blood pressure, high-density lipoprotein cholesterol and low-density lipoprotein cholesterol was investigated.

Results:

Mean vascular reactivity index was 1.87 ± 0.53. Vascular reactivity index, marker of endothelial dysfunction, showed a significant correlation with lower nadir CD4 count (p = 0.003) as well as low-density lipoprotein cholesterol (p = 0.02). No additional significant correlation between vascular reactivity index and the rest of the investigated variables was found.

Conclusion:

Vascular reactivity index, a clinical predictor of endothelial dysfunction, is associated with lower nadir CD4-T cell and low-density lipoprotein cholesterol in HIV-infected men with no history of hypertension or diabetes and before clinical evidence of cardiovascular disease.

Different Effects of Volatile and Nonvolatile Anesthetic Agents on Long-Term Survival in an Experimental Model of Hemorrhagic Shock

BACKGROUND

We investigated whether the cardioprotective, volatile gas anesthetic agent, isoflurane, could improve survival and organ function from hemorrhagic shock in an experimental rat model, compared to standard nonvolatile anesthetic agent ketamine/xylazine.

METHODS

Sprague Dawley rats (both genders) were randomized to receive either intraperitoneal ketamine/xylazine (K/X, 90 and 10 mg/kg; n = 12) or isoflurane (5% isoflurane induction and 2% maintenance in room air; n = 12) for anesthesia. Blood was withdrawn to maintain mean arterial blood pressure at 30 mm Hg for 1 hour, followed by 30 minutes of resuscitation with shed blood. Rats were allowed to recover and survive for 6 weeks.

RESULTS

During the shock phase, the total withdrawn blood volume (expressed as % of estimated total blood volume) to maintain a level of hypotension of 30 mm Hg was significantly higher in the isoflurane group (51.0% ± 1.5%) than in the K/X group (45.3% ± 1.8%; P = .023). Recovery of blood pressure during the resuscitation phase was significantly improved in the isoflurane group compared to the K/X group. The survival rate at 6 weeks was 1 (8.3%) of 12 in rats receiving K/X and 10 (83.3%) of 12 in rats receiving isoflurane (P < .001). Histology performed at 6 weeks demonstrated brain infarction in the 1 surviving rat receiving K/X; no brain infarction occurred in the 10 surviving rats that received isoflurane. No infarction was detected in heart, lung, liver, or kidneys among the surviving rats.

CONCLUSIONS

Isoflurane improved blood pressure response to resuscitation and resulted in significantly higher long-term survival rate.

Pathophysiology and diagnosis of coronary microvascular dysfunction in ST-elevation myocardial infarction

Early mechanical reperfusion of the epicardial coronary artery by primary percutaneous coronary intervention (PCI) is the guideline-recommended treatment for ST-elevation myocardial infarction (STEMI). Successful restoration of epicardial coronary blood flow can be achieved in over 95% of PCI procedures. However, despite angiographically complete epicardial coronary artery patency, in about half of the patients perfusion to the distal coronary microvasculature is not fully restored, which is associated with increased morbidity and mortality. The exact pathophysiological mechanism of post-ischaemic coronary microvascular dysfunction (CMD) is still debated. Therefore, the current review discusses invasive and non-invasive techniques for the diagnosis and quantification of CMD in STEMI in the clinical setting as well as results from experimental in vitro and in vivo models focusing on ischaemic-, reperfusion-, and inflammatory damage to the coronary microvascular endothelial cells. Finally, we discuss future opportunities to prevent or treat CMD in STEMI patients.

Improved Long-term Survival with Remote Limb Ischemic Preconditioning in a Rat Fixed-Pressure Hemorrhagic Shock Model

PURPOSE

We investigated whether bilateral, lower limb remote ischemic preconditioning (RIPC) improved long-term survival using a rat model of hemorrhagic shock/resuscitation.

METHODS

Rats were anesthetized, intubated and ventilated, and randomly assigned to RIPC, induced by inflating bilateral pressure cuffs around the femoral arteries to 200 mmHg for 5 min, followed by 5-min release of the cuffs (repeated for 4 cycles), or control group (cuffs were inflated to 30 mmHg). Hemorrhagic shock was induced by withdrawing blood to a fixed mean blood pressure of 30 mmHg for 30 min, followed by 30 min of resuscitation with shed blood. Rats remained anesthetized for 1 h during which hemodynamics were monitored then they were allowed to survive for 6 weeks.

RESULTS

The percentage of estimated total blood volume withdrawn to maintain a level of 30 mmHg was similar in both groups. RIPC significantly increased survival at 6 weeks: 5 of 27 (19%) rats in the control group and 13 of 26 (50%; p = 0.02) rats in the RIPC group survived. Blood pressure was higher in the RIPC group. The diastolic internal dimension of the left ventricle, an indicator of circulating intravascular blood volume, was significantly larger in the RIPC group at 1 h after initiation of resuscitation compared to the control group (p = 0.04). Left ventricular function assessed by fractional shortening was comparable in both groups at 1 h after initiation of resuscitation. Blood urea nitrogen (BUN) was within normal range in the RIPC group (17.3 ± 1.2 mg/dl) but elevated in the control group (22.0 ± 1.7 mg/dl) at 48 h after shock.

CONCLUSIONS

RIPC significantly improved short-term survival in rats that were subjected to hemorrhagic shock, and this benefit was maintained long term. RIPC led to greater circulating intravascular blood volume in the early phase of resuscitation and improved BUN.

Remote Ischemic Conditioning in Acute Myocardial Infarction and Shock States

Remote ischemic conditioning is the phenomenon whereby brief, nonlethal episodes of ischemia in one organ (such as a limb) protect a remote organ from ischemic necrosis induced by a longer duration of severe ischemia followed by reperfusion. This phenomenon has been reproduced by dozens of experimental laboratories and was shown to reduce the size of myocardial infarction in many but not all clinical studies. In one recent large clinical trial, remote ischemic conditioning induced by repetitive blood pressure cuff inflations on the arm did not reduce infarct size or improve clinical outcomes. This negative result may have been related in part to the overall success of early reperfusion and current adjunctive therapies, such as antiplatelet therapy, antiremodeling therapies, and low-risk patients, that may make it difficult to show any advantage of newer adjunctive therapies on top of existing therapies. One relevant area in which current outcomes are not as positive as in the treatment of heart attack is the treatment of shock, where mortality rates remain high. Recent experimental studies show that remote ischemic conditioning may improve survival and organ function in shock states, especially hemorrhagic shock and septic shock. In this study, we review the preclinical studies that have explored the potential benefit of this therapy for shock states and describe an ongoing clinical study.

Lessons learned about stress and the heart after major earthquakes

There is evidence that certain stressors can trigger cardiovascular events. Several studies have now demonstrated an increase in major adverse cardiac events associated with natural disasters such as an earthquake. The purpose of this paper is to review the literature on earthquakes and cardiovascular events. Reports from 13 major quakes were reported. Earthquakes have been associated with a number of cardiac events including sudden cardiac death, fatal myocardial infarction (MI), myocardial infarction, stress cardiomyopathy, heart failure, stroke, arrhythmias, hypertension and pulmonary embolism. Most reports were associated with earthquakes of magnitude 6.0 or greater. Cardiac events were reported within hours of the quakes. In some reports there was a sharp spike in cardiac events followed by a decrease; but in other quakes the increases in cardiac events lasted weeks, months and even years. There often was an association between the cardiac events and amount of personal property loss. The Great East Japan Earthquake was an unusual event in that it was associated with a major tsunami and cardiac events appeared worse in inundated areas due to flooding. Some but not all reports suggested more MIs associated with early morning earthquakes that woke up the population. Hospitals in earthquake-prone areas should consider developing plans for handling increases in myocardial infarctions and other cardiac events that are associated with earthquakes.

Coronary artery calcium testing: A call for universal coverage

Heart attacks kill more Americans than all cancers combined. Fatal heart attack victims have no symptoms until minutes before they die, hence early detection of high-risk asymptomatic individuals is needed. Even though heart attacks kill and cost more than cancers, as a nation we spend over 20 times more on screening for asymptomatic cancer than for asymptomatic atherosclerotic cardiovascular disease (ASCVD), the underlying cause of heart attacks. Currently, payers only cover screening for risk factors of ASCVD such as blood pressure and blood cholesterol. This approach tends to miss high-risk and over-treat low-risk individuals. Although treadmill stress testing with ECG is not indicated for ASCVD detection in asymptomatic individuals, it is done often, and frequently leads to misleading conclusions or unnecessary downstream diagnostic procedures. For example, former President Clinton had passed his treadmill stress tests for several years during his presidential annual checkup but had a heart attack shortly after his presidency. This common practice is a waste of our limited resources. Instead, a more accurate risk assessment using coronary artery calcium (CAC) testing is available; and has just been adopted by ACC/AHA guidelines, however payers do not cover it. CAC is measured non-invasively with a 5-minute CT-scan of the heart, and costs less than $200, whereas cancer screening with colonoscopy and mammography costs over $3000. There is an opportunity to save lives and dollars if CAC testing is covered for appropriately selected individuals. Texas has already passed HB1290 to mandate CAC coverage. Other states must step up and take actions.

Cardiorenal Safety of OTC Analgesics

Over-the-counter analgesics are used globally for the relief of acute pain. Although effective, these agents can be associated with adverse effects that may limit their use in some people. In the early 2000s, observations from clinical trials of prescription-strength and supratherapeutic doses of nonselective and cyclooxygenase-2-selective nonsteroidal anti-inflammatory drugs (NSAIDs) raised safety concerns regarding the risk of cardiovascular adverse effects with the use of these medications. Subsequently, the US Food and Drug Administration mandated additional study of the cardiovascular safety of NSAIDs for a more comprehensive understanding of their risk. As these data were being collected, and based on a comprehensive review of prescription data and the recommendations of the US Food and Drug Administration Advisory Committee, the warning labels of over-the-counter NSAIDs were updated to emphasize the potential cardiovascular risks of these agents. The recently reported “Prospective Randomized Evaluation of Celecoxib Integrated Safety versus Ibuprofen or Naproxen” (PRECISION) trial, in which participants with osteoarthritis or rheumatoid arthritis and underlying cardiovascular risk factors were treated with prescription-strength celecoxib, ibuprofen, or naproxen, revealed similar rates of cardiovascular events (death from cardiovascular causes including hemorrhagic death, nonfatal myocardial infarction, or nonfatal stroke) among the 3 treatment groups. Although informative, the cardiovascular safety findings derived from PRECISION cannot be extrapolated to the safety of the over-the-counter pain relievers ibuprofen and naproxen, given that the doses used were higher (mean [standard deviation]: ibuprofen, 2045 [246] mg; naproxen, 852 [103] mg) and the durations of use longer (∼20 months) than recommended with over-the-counter use of NSAIDs, which for ibuprofen is up to 10 days. This review discusses the cardiorenal safety of the most commonly used over-the-counter analgesics, ibuprofen, naproxen, and acetaminophen. Available data suggest that there is little cardiovascular risk when over-the-counter formulations of these agents are used as directed in their labels.

Beyond Reperfusion: Acute Ventricular Unloading and Cardioprotection During Myocardial Infarction

Heart failure is a major cause of morbidity and mortality around the world, and myocardial infarction is its leading cause. Myocardial infarction destroys viable myocardium, and this dead tissue is replaced by a non-contractile scar that results in impaired cardiac function and a significantly increased likelihood of the patient developing heart failure. Limiting infarct scar size has been the target of pre-clinical and clinical investigations for decades. However, beyond reperfusion, few therapies have translated into the clinic that limit its formation. New approaches are needed. This review will focus on new clinical and pre-clinical data demonstrating that acute ventricular unloading prior to reperfusion by means of percutaneous left ventricular support devices reduces ischemia-reperfusion injury and limits infarct scar size. Emphasis will be given to summarizing our current mechanistic understanding of this new therapeutic approach to treating myocardial infarction.