Obesity-induced vena cava compression syndrome: a case report of a rare precipitant of a type 2 myocardial infarction in a patient with critical aortic stenosis

Background

Obesity is a global health problem of increasing prevalence with a broad range of multisystem complications. An under-recognized complication of severe obesity is the potential haemodynamic compromise that may arise due to pathological external compression of the inferior vena cava whilst lying in the supine position, a phenomenon known as obesity-induced vena cava compression syndrome.

Case summary

A 56-year-old independent woman presented to a rural Australian hospital for routine dressing care for bilateral lymphoedema on a background of class III morbid obesity (weight 197 kg, body mass index 68.55 kg/m³) and aortic stenosis. Whilst laid in the supine position with both legs elevated to aid lower limb venous return, the patient developed angina with associated troponin rise (15 to 75 to 332 ng/L) and inferolateral territory ischaemic changes on electrocardiogram. The pain then resolved shortly after restoring the patient to the upright position. A transthoracic echocardiogram showed critical bicuspid aortic stenosis. Computerized tomography coronary angiogram showed no significant coronary artery disease. Following multidisciplinary discussions, a transcatheter aortic valve insertion was performed via a transfemoral approach. Post-procedure, she went into atrial fibrillation, she was cardioverted into a sinus rhythm with new left bundle branch block. There were no complications otherwise, and the patient was discharged home following a brief period of convalescence.

Discussion

We describe a case of suspected obesity-induced vena cava compression syndrome precipitating a type 2 myocardial infarction in a pre-load dependent patient with critical bicuspid valve aortic stenosis. This case highlights a potential haemodynamic consequence of morbid obesity in the supine position.

Impact of Surgical and Transcatheter Aortic Valve Replacement on Frailty Score

OBJECTIVE

Frailty is common in the aortic stenosis (AS) population and impacts outcomes after both transcatheter and surgical aortic valve replacement (TAVR and sAVR, respectively). Frailty can significantly impact the decision regarding the suitability of a patient for aortic valve intervention, with frail patients often excluded. Since many frailty tools use indicators which may be influenced by AS itself, some of which are subjectively symptom driven, we sought to determine the impact of intervention on frailty scores.

METHODS

A prospective, observational cohort study included patients being assessed for aortic valve (AV) intervention with either TAVR or sAVR due to severe aortic stenosis. Patients were assessed for symptoms at baseline, and 1- and 6-months post intervention subjectively, using the New York Heart Association (NYHA) class and the Kansas City Cardiomyopathy Questionnaire (KCCQ), and objectively, using a 6-minute walk test (6MWT). These were compared with frailty at baseline and final review using the Fried Frailty Scale (FFS).

RESULTS AND CONCLUSIONS

Sixty-six (66) patients completed pre- and post-intervention reviews. The mean FFS score was significantly lower, indicating less frailty, at 6 months relative to pre procedure (1.18 vs 1.73, p=0.002). This correlated with the change in symptoms (p<0.001). Between intervention groups, the final mean FFS of both groups decreased significantly, with TAVR to 1.33 (p=0.030) and sAVR to 0.8 (p=0.015). There was no difference in the degree of improvement between interventions (p=0.517). Aortic valve intervention improves frailty scores in both TAVR and sAVR treated patients.

Impact of increased augmentation index and valvuloarterial impedance on symptom recovery after aortic valve replacement for severe aortic stenosis

Background

Aortic stenosis (AS) is a common valvular disorder with a large symptomatic burden resulting from increased myocardial workload due to valvular obstruction. The contribution of increased afterload from arterial stiffness on symptoms is uncertain. The purpose of this analysis was to determine the symptomatic impact of arterial stiffness as determined by Applanation Tonometry.

Methods

Eighty-eight patients with severe AS undergoing intervention with transcatheter aortic valve replacement (TAVR) (n = 65) or surgical aortic valve replacement (SAVR) (n = 23) were prospectively enrolled. Symptoms were recorded using the NYHA Class, Kansas City Cardiomyopathy Questionnaire (KCCQ) and a 6 min walk test (6MWT) at baseline, and 1- and 6-months post intervention. Pulse Wave Analysis (PWA) using Applanation Tonometry was performed at all reviews, including the augmentation index (AIx).

Results

Patients undergoing TAVR were older, with worse renal function and lower aortic valve areas, but were otherwise similar. There was no significant difference between the augmentation index of our AS population compared with an age matched reference population (p = 0.89).

Symptoms significantly improved after intervention according to NYHA Class, KCCQ and 6MWT. Additionally, with adjustment, the initial augmentation index correlated with the final KCCQ (Coeff. = −0.383, p = 0.02) and NYHA Class (Coeff. = 0.012, p = 0.03) and a baseline AIx value in the top quartile resulted in a significantly worse final KCCQ (95.1 v 85.2, p = 0.048) relative to the bottom 3 quartiles.

Conclusions

According to our analysis, an elevated baseline AIx is associated with a poorer symptomatic recovery after aortic valve intervention and so is worthy of consideration when assessing potential symptomatic benefit.

Multidisciplinary transcatheter aortic valve replacement heart team programme improves mortality in aortic stenosis

Objectives

To analyse the effect of the implementation of a transcatheter aortic valve replacement (TAVR) and multidisciplinary heart team programme on mortality in severe aortic stenosis (AS).

Methods

A retrospective, observational cohort study was performed using the echocardiography, cardiothoracic surgery and TAVR databases between 1 January 2006 and 31 December 2016. Outcomes were compared between the pre- and post-TAVR programme eras in a tertiary referral centre providing transcatheter and surgical interventions for AS.

All-cause mortality within 5 years from diagnosis was determined for 3399 patients with echocardiographically defined severe AS.

Results

Of 3399 patients, there were 210 deaths (6.2%) at 30 days and 1614 deaths (47.5%) at 5 years.

Overall, patients diagnosed in the post-TAVR programme era were older, with a lower ejection fraction and more severe AS, but were less comorbid.

Among 705 patients undergoing intervention, those in the post-TAVR programme era were older, with a lower ejection fraction and more severe AS but no significant differences in comorbidities.

Using an inverse probability weighted cohort and a Cox proportional hazards model, a significant mortality benefit was noted between eras alone (HR=0.86, 95% CI 0.77 to 0.97, p=0.015). When matching for age, comorbidities and valve severity, this benefit was more evident (HR=0.82, 95% CI 0.73 to 0.92, p=0.001).

After adjusting for the presence of aortic valve intervention, a significant benefit persisted (HR=0.84, 95% CI 0.75 to 0.95, p=0.005).

Conclusion

The implementation of a TAVR programme is associated with a mortality benefit in the population with severe AS, independent of the expansion of access to intervention.

Effect of Balloon Aortic Valvuloplasty on Mortality in Patients With Severe Aortic Stenosis Prior to Conservative Treatment and Surgical or Transcatheter Aortic Valve Replacement

BACKGROUND

Outcomes following an initial strategy of balloon aortic valvuloplasty (BAV) prior to medical therapy or intervention with surgical or transcatheter aortic valve replacement (SAVR or TAVR) are unclear in the modern transcatheter intervention era.

METHODS

A retrospective, observational cohort study of the echocardiography, cardiothoracic surgery and TAVR databases between 1 January 2006 and 31 December 2016 was performed to compare outcomes between all patients with severe aortic stenosis (AS) treated with or without BAV prior to medical or invasive therapy.

RESULTS

3,142 patients were available for analysis. 223 BAV treated patients had lower mortality relative to medically treated patients, particularly early (20.1% v. 7.6% at 6 months, 58.1% v. 52.5% at 5 years). Over 5 years, the adjusted hazard ratio (HR) was 0.62 (95% CI 0.48-0.80, p < 0.001). Compared with 630 patients proceeding directly to intervention, 75 patients receiving BAV experienced a higher mortality (HR = 2.76, 95% CI 2.07-3.66, p < 0.001). No subsequent excess perioperative mortality was observed with BAV compared with those receiving surgery directly (HR = 1.45, 95% CI 0.91-2.31, p = 0.117).

CONCLUSIONS

The risk associated with BAV is low, and improves mortality compared with medical therapy. Balloon aortic valvuloplasty treated patients have poorer outcomes, but treatment with BAV does not increase perioperative mortality and may lessen it.

Catheter-based renal denervation for resistant hypertension: Twenty-four month results of the EnligHTN I first-in-human study using a multi-electrode ablation system

BACKGROUND

Long term safety and efficacy data of multi-electrode ablation system for renal denervation (RDN) in patients with drug resistant hypertension (dRHT) are limited.

METHODS AND RESULTS

We studied 46 patients (age: 60 ± 10 years, 4.7 ± 1.0 antihypertensive drugs) with drug resistant hypertension (dRHT). Reduction in office BP at 24 months from baseline was -29/-13 mmHg, while the reduction in 24-hour ambulatory BP and in home BP at 24 months were -13/-7 mmHg and -11/-6 mmHg respectively (p<0.05 for all). A correlation analysis revealed that baseline office and ambulatory BP were related to the extent of office and ambulatory BP drop. Apart from higher body mass index (33.3 ± 4.7 vs 29.5 ± 6.2 kg/m(2), p<0.05), there were no differences in patients that were RDN responders defined as ≥10 mmHg decrease (74%, n=34) compared to non-responders. Stepwise logistic regression analysis revealed no prognosticators of RDN response (p=NS for all). At 24 months there were no new serious device or procedure related adverse events.

CONCLUSIONS

The EnligHTN I study shows that the multi-electrode ablation system provides a safe method of RDN in dRHT accompanied by a clinically relevant and sustained BP reduction.

New antiplatelet agents and the role of platelet function testing in acute coronary syndromes

BACKGROUND

Dual antiplatelet therapy is a guideline mandated for patients with acute coronary syndromes (ACS). Despite its use, thrombotic events continue to occur both early and late. Platelet function testing has been used to define the in vitro effects of new antiplatelet agents, and it has been suggested that it be used to choose therapy. The role of platelet function testing, particularly with newer antiplatelet agents, remains unclear.

OBJECTIVE

We review the rationale for platelet function testing and its application in monitoring patients on antiplatelet therapy. We also review recent clinical trials of newer antiplatelet agents. On the basis of this review, we reach conclusions on the current role of antiplatelet function testing in monitoring modern antiplatelet therapy and the role of the new antiplatelet agents in the treatment of ACS.

METHODS

We reviewed recent publications on platelet function testing and clinical trials of newer antiplatelet therapies compared with clopidogrel.

RESULTS

Platelet function testing is complex, but there is now a bedside test, VerifyNow. High platelet reactivity has been associated with worse cardiovascular outcomes in patients undergoing percutaneous coronary intervention. Recent clinical trials have not found any advantage in outcomes in patients who have their therapy adjusted by monitoring their platelet function. Newer agents, prasugrel, ticagrelor, and cangrelor, produce more rapid, complete, less variable effects on platelet function than clopidogrel. Prasugrel was found to improve outcomes compared with clopidogrel in patients with ACS undergoing percutaneous intervention. Ticagrelor is beneficial in all patients with ACS and reduces cardiovascular mortality compared with clopidogrel. Cangrelor improves outcomes in patients undergoing stenting. Recent studies to assess the role of platelet function monitoring of the effects of clopidogrel and modifying treatments have not been successful.

CONCLUSION

Recent clinical trials have indicated that newer antiplatelet agents have advantages over clopidogrel in the treatment of ACS. Platelet function testing gives us a guide to the timing, efficacy, and variability of therapy and can correlate with poor patient outcomes; however, the use of antiplatelet function testing to tailor therapy does not seem appropriate.