Trends in the use of mechanical and bioprosthetic aortic valve replacement in the era of transcatheter aortic valve replacement

Background

The choice between a mechanical versus a bioprosthetic valve in aortic valve replacement (AVR) is based on life expectancy, bleeding risk and co-morbidities, since bioprosthetic AVR (bAVR) as compared to mechanical AVR (mAVR), are associated with a more rapid structural deterioration. However, refinements in bioprosthetic valves and the introduction of transcatheter aortic valve replacement (TAVR) (potential for valve-in-valve procedures), will most likely influence valve selection in the future. The impact of widespread transcatheter valve replacements, on the decision to use bAVR versus mAVR, in the contemporary era and subsequent outcomes remain to be determined.

Purpose

The goal of our study was to assess trends in utilization of bAVR and mAVR in the United States while, assessing in-hospital mortality over time.

Methods

The National Inpatient database (2009–18) was used to study trends in admissions for bAVR and mAVR and in-hospital mortality over time. Survey estimation commands were used to determine weighted national estimates.

Results

There were 700,896 inpatient visits for AVR with 70.1% (95% CI 69.2%-71.1%) and 29.9% (95% CI 28.9%-30.8%) visits for bAVR and mAVR, respectively. Those undergoing bAVR were significantly older, [bAVR (69.8 years) vs mAVR (62.7 years) p<0.001]. Heart failure, cardiac arrhythmias, hypertension, diabetes with complications and renal failure were more common in those undergoing a bAVR. Through the course of the study period, the rates of mAVR decreased across all age groups (p trend <0.001), including patients younger than 50 years (p trend <0.001). Both crude (OR = 1.20 95% CI 1.13–1.27) and adjusted (OR = 1.34 95% CI 1.25–1.44) inpatient mortality was higher amongst mAVR recipients.

Conclusions

In the contemporary TAVR era, the utilization of mAVR has decreased across all age groups, including those younger than 50 years old. Although mAVR recipients were healthier with significantly less co-morbidities, inpatient mortality was higher after mAVR compared to bAVR. In addition to understanding the causes accounting for the higher mortality after mAVR, future research should focus on developing TAVR friendly bAVR; possibly enhancing our ability to perform percutaneous valve-in-valve procedures in the future.

Funding Acknowledgement

Type of funding sources: None.

Gender disparities in the treatment of aortic stenosis – an analysis of the united states national inpatient sample (2009–2018)

Introduction

Gender disparity in the management of a variety of cardiovascular disorders has been well established. Studies have shown that women are less likely to undergo surgical aortic valve replacement (SAVR), and have higher mortality and health care cost in the management of aortic stenosis (AS). The impact of transcatheter aortic valve replacement (TAVR) on this gender disparity has not been well established.

Purpose

We sought to examine the impact of gender on outcomes following aortic valve replacement for AS in the era of routine transcatheter valve replacement.

Methods

We used the National Inpatient Sample (2009–18), a representative probability sample of the United States, to study visits for all aortic valve replacements and in-hospital outcomes as a function of gender. Survey estimation commands were used to provide national estimates.

Results

There were an estimated 431,344 SAVR and 189,137 TAVR inpatient visits during the periods of 2009–18 and 2011–18, respectively with a higher representation of women in the TAVR cohort (46.4% [95% CI, 45.9%-46.9%]) than SAVR (36.8% [95% CI, 36.4%-37.2%]). Women were slightly older with higher prevalence of uncomplicated hypertension (HTN) and pulmonary circulation disorders. However, women exhibited a lower prevalence of complicated HTN, complicated diabetes mellitus, prior percutaneous coronary intervention, prior coronary artery bypass grafting, peripheral vascular disease and renal failure. In-hospital mortality was higher in women after SAVR (3.8%±0.1 vs 2.7%±0.07, p<0.001) and TAVR (2.4%±0.1 vs 1.7%±0.1, p<0.001) compared to men. Female SAVR patients had higher rates of permanent pacemaker (PPM) implantation, stroke and significant bleeding (5.9%±0.1 vs 5%±0.1, 2.8%±0.1 vs 2.3%±0.07, and 37.8%±0.8 vs 29.8%±0.6; p<0.001, respectively) but lower rates of acute kidney injury (AKI) (16.4%±0.3 vs 20.3%±0.3, p<0.001). In addition, women undergoing TAVR had higher rates of stroke and significant bleeding (2.4%±0.1 vs 1.6%±0.09 and 28.7%±0.6 vs 22%±0.5; p<0.001 respectively) but lower rates of PPM and AKI (9.5%±0.3 vs 10.7%±0.2 and 11.3%±0.3 vs 13.4%±0.3; p<0.001, respectively). There was a reduction in mortality, compared to the early TAVR era, for all groups during the study period, particularly in female TAVR patients (from approximately 5.2% to 1.7%). In-hospital mortality for women was lower after TAVR than SAVR, both after multivariable adjustment (OR = 0.33, 95% CI 0.24–0.45) and propensity matching (mean difference 1.28%±0.49).

Conclusions

TAVR appears to have narrowed the gender disparity in the management of AS. Although women continue to have a higher in-hospital mortality following both TAVR and SAVR compared to men, TAVR is associated with a lower inpatient mortality in women compared to SAVR. Thus, TAVR may represent a bridge for the gender gap in aortic valve replacement.

Funding Acknowledgement

Type of funding sources: None.

Does the availability of transcatheter aortic valve replacement impact inpatient outcomes after surgical aortic valve replacement? Analysis of the national inpatient sample

Background

With the introduction of transcatheter aortic valve replacement (TAVR), the treatment of aortic stenosis (AS) has experienced a paradigm shift, altering patient selection for surgical aortic valve replacement (SAVR) over the past decade. What remains to be determined is the impact of a hospital's ability to offer TAVR, in the contemporary era, on inpatient outcomes following SAVR.

Purpose

The goal of this study was to assess inpatient mortality and the use of mechanical aortic valve replacement (mAVR) in patients undergoing SAVR at TAVR versus non-TAVR centers in the United States.

Methods

The National Inpatient Sample (2011–18), a probability sample of inpatient visits in the United States, was used to study trends in admissions for SAVR at TAVR and non-TAVR centers; in-hospital mortality was trended over time. Survey estimation commands were used to determine weighted national estimates.

Results

There were 559,365 inpatient visits for SAVR with 75.2% (95% CI 74.2%-76.2%) and 24.7% (95% CI 23.8%-25.8%) receiving bioprosthetic SAVR (bAVR) and mAVR, respectively at TAVR centers and 64.5% (95% CI 63.3%-65.6%) and 35.5% (95% CI 34.4%-36.7%) receiving bAVR and mAVR, respectively at non-TAVR centers. SAVR recipients at non-TAVR centers were older when compared to recipients at TAVR centers (68.3±0.09 vs 66.9±0.11 years p<0.001). Heart failure, cardiac arrhythmias, peripheral vascular disorders, complicated hypertension and diabetes, renal failure and liver disease were more common in patients undergoing SAVR at TAVR-centers. During the study period, both crude (OR = 0.78 95% CI 0.73–0.83) and adjusted (OR = 0.79 95% CI 0.73–0.86) inpatient mortality was lower amongst SAVR recipients at TAVR centers. The utilization rates of mAVR at both TAVR and non-TAVR centers decreased over time amongst all age groups (p trend <0.001).

Conclusions

Patients undergoing SAVR at TAVR centers were younger and had more co-morbidities compared to patients undergoing SAVR at non-TAVR centers. Although patients undergoing SAVR at TAVR centers had significantly more co-morbidities, inpatient mortality was lower at TAVR centers compared to non-TAVR centers. Further research is needed to determine whether the impact of a multidisciplinary cardiac approach resulted in significant differences in patient selection for SAVR, due to the availability of TAVR, influencing patient outcomes.

Funding Acknowledgement

Type of funding sources: None.

Syncope masquerading as a panic disorder: role of the subcutaneous loop recorder in eliciting the appropriate diagnosis

The present case describes a 49-year-old woman with apparent panic disorder in whom the Reveal Plus, a newly developed subcutaneous loop recorder, was used to show that the panic attacks were secondary to prolonged episodes of ventricular asystole.

Asymptomatic left ventricular permanent pacemaker malposition detected on routine follow-up--a case report

The authors present an asymptomatic left ventricular pacemaker lead malposition that was detected upon routine 2-D Echocardiography. Clinical implication diagnosis and therapeutic options on left ventricular pacemaker lead malposition are discussed.

Prolonged QRS duration (QRS >/=170 ms) and left axis deviation in the presence of left bundle branch block: A marker of poor left ventricular systolic function?

BACKGROUND

Left bundle branch block (LBBB) is commonly associated with structural heart disease and left ventricular dysfunction. We propose that the QRS duration and degree of left-axis deviation (LAD) identify significant left ventricular systolic dysfunction in patients with LBBB.

METHODS

In this prospective study the ejection fraction (EF) of 300 consecutive patients with LBBB was evaluated by echocardiography. The relationship between QRS duration and LAD (axis between -30 degrees and -90 degrees ) and EF were derived.

RESULTS

There was no significant difference in age, sex, presence of ischemic or nonischemic cardiomyopathy and valvular heart disease, and EF among the patients with or without LAD. The EF of patients with QRS >/=170 milliseconds with LAD (n = 20) and without LAD (n = 18) was 25% +/- 16% and 23% +/- 13%, respectively (P =.71). The mean EF (24% +/- 10%) of the patients with a QRS duration of >/=170 milliseconds (n = 38) was significantly lower than the mean EF (36% +/- 16%) of the patients with a QRS duration of <170 milliseconds (n = 262, P <.015). The QRS duration also had a significant (P <.001) inverse correlation with EF (R = 0.37, adjusted R (2) = 0.13, SE of estimate = 16.21). However, the QRS axis was not significantly correlated with EF and did not have added predictive value.

CONCLUSIONS

The QRS duration has a significant inverse relationship with EF and prolongation of QRS duration (>/=170 milliseconds) in the presence of LBBB is a marker of significant left ventricular systolic dysfunction. The presence of LAD in LBBB does not signify a further decrease in EF.

Adolescents in the age of AIDS: myths, misconceptions, and misunderstandings regarding sexually transmitted diseases

The purpose of this study is twofold: to evaluate the extent of knowledge possessed by young people residing in an urban sexually transmitted disease (STD) and AIDS epicenter about STDs, including AIDS; and to determine whether knowledge levels varied by age, gender, race/ ethnicity, and/or previous health instruction. A total of 867 adolescents (472 females and 395 males) attending a large public high school in New York City completed a self-administered survey. Levels of knowledge about AIDS transmission and prevention were high (mean percentage correct = 91.8%). Nonetheless, adolescent respondents locked awareness about the prevalence of common STDs, had limited understanding of the ways in which these diseases can be transmitted and prevented, and were unaware of potentially serious sequelae resulting from exposure to infectious agents (e.g., infertility from chlamydial infections). Young people who had taken a health education course in which STDs were discussed did slightly better on the knowledge survey than did their peers. While the prevention of HIV infection is, and should be, a national priority, more concerted efforts are needed to better educate young people about other STDs in the overall context of sexual health.

Time dependent changes in duration of ventricular repolarization after AV node ablation: insights into the possible mechanism of postprocedural sudden death

Although effective, there is a disturbing incidence of sudden death after AV node ablation. The mechanism may be related to proarrhythmia associated with prolongation in ventricular repolarization from the sudden decrease in heart rate. To examine this issue, we studied 15 patients undergoing complete radiofrequency ablation of the AV node for rapid atrial arrhythmias. Twelve-lead ECGs of paced rhythms at rates of 60, 80, 100, and 120 beats/min were recorded at time points of 30 minutes, 24 hours, 1 week, and 1 month after ablation. The QT interval was measured in the limb and precordial leads with the best T wave offset. The change in the QT interval (delta QT) relative to the measurement at 30-minute postablation was calculated. For comparison, a similar procedure was performed on patients receiving pacemakers for primary bradycardia (n = 5). The mean QT interval at 60 beats/min, 30-minutes postablation was significantly longer than at time points thereafter (482 +/- 39 vs 446 +/- 28 ms at 1 month, limb leads, for example, P < 0.05). Analysis of delta QT revealed a significant shortening of the QT interval at nearly every paced rate at every time point relative to the value at 30-minute postablation. The QT intervals shortened and stabilized after 24 hours. Neither the QT interval nor delta QT changed significantly in patients paced for primary bradycardia. We conclude that there is a relative increase in the duration of ventricular repolarization after AV node ablation, which then decreases and stabilizes after 24 hours. Such changes are not seen in patients being paced for primary bradycardia. This data is consistent with the hypothesis that sudden death after AV node ablation may be related to proarrhythmia from prolonged ventricular repolarization.

Effects of aging and gender on QT dispersion in an overtly healthy population

The objective of this study was to measure the normal variation of QT dispersion (QTd) with respect to age and gender. The QT interval is a measure of the duration of ventricular depolarization and repolarization, while the QTd is a measure of the variability of the ventricular recovery time. The QTd has been suggested as a means of identifying those patients at risk for sustained ventricular tachyarrythmias and sudden cardiac death (SCD). A total of 250 patients (120 women, 130 men; age range 20-86 years) were recruited for this study. The QT intervals were measured in each of the 12 standard leads of the electrocardiogram. Data are presented as mean (mu) +/- SD. The QTd did not vary significantly within the same gender. A significant difference (P < 0.001) was noted in QTd between men (age [mu] = 53.3 +/- 15.6 years, QTd = 0.044 +/- 0.019 s) and women (age [mu] = 52.1 +/- 15.1 years, QTd = 0.034 +/- 0.015 s). Overall, men had a greater QTd, while women had a longer QT. In conclusion, we found that men had a longer QTd, which may explain the increased risk of SCD. However, women have a longer QT interval with a smaller QTd. A longer QTmin, as opposed to a longer QTmax, is responsible for the shorter QTd in women. This longer QTmin in women may predispose to an increased risk of drug induced torsades de pointes.

Double-wave reentry in orthodromic atrioventricular reciprocating tachycardia: paradoxical shortening of the tachycardia cycle length with development of ipsilateral bundle branch block

INTRODUCTION

Attempts to terminate reentrant tachyarrhythmias by rapid pacing may accelerate the tachycardia. One mechanism for acceleration is double-wave reentry, where two simultaneous wavefronts travel around the same circuit.

METHODS AND RESULTS

We report pacing acceleration of AV reciprocating tachycardia (AVRT) due to double-wave reentry in a patient with Wolff-Parkinson-White syndrome. The patient had presented with atrial fibrillation and rapid conduction across a left lateral bypass tract. Intravenous procainamide was given during electrophysiologic study because of incessant atrial fibrillation and restored sinus rhythm. Orthodromic AVRT was induced and attempts to terminate the AVRT with right ventricular pacing initiated two alternate tachycardias, both with a left bundle branch block (LBBB) morphology. The first tachycardia, as expected for bundle branch block ipsilateral to the bypass tract, had a longer cycle length (CL) than the original tachycardia (366 msec compared to 297 msec). The second tachycardia had a paradoxically shorter CL, 238 msec compared to 297 msec. Electrogram analysis revealed that the circuit traversed by the accelerated LBBB tachycardia was the same as the slower LBBB tachycardia. The activation sequence revealed two independent wavefronts, traversing this common circuit. As described previously in experimental models, double-wave reentry was initiated when an antidromic-stimulated impulse blocked before colliding with the previous orthodromic impulse, thus allowing two orthodromic impulses to circulate within the circuit.

CONCLUSION

We speculate that conduction slowing by procainamide combined with the intrinsic AV nodal delay resulted in the necessary increase in the excitable gap required to develop double-wave reentry. This is the first description of sustained double-wave reentry in humans.

Rhythm management in atrial fibrillation--with a primary emphasis on pharmacologic therapy: Part 3

Atrial fibrillation (AF) is the most common, sustained, symptomatic tachyarrhythmia that clinicians are called upon to manage. Management strategies include ventricular rate control coupled with anticoagulation, versus restoration and maintenance of sinus rhythm. Rate control may be achieved pharmacologically, with agents that impair AV nodal conduction directly and/or by increasing parasympathetic/sympathetic balance, or by modifying or ablating the AV nodal region anatomically. Rhythm control may be achieved by electrical or pharmacologic conversion followed by maintenance of sinus rhythm by pharmacologic (or occasionally ablative) therapies. This article will present current approaches to rate and rhythm control issues in atrial fibrillation. Parts 1 and 2, published previously, dealt with rate control and with the restoration of sinus rhythm. Part 3, the current article, details the selection process of choosing a therapy to maintain sinus rhythm, including the likelihood of success, the risks of therapy, and individualization of therapy as dependent upon the nature of the structural heart disease present. It also discusses nonpharmacologic approaches that have been recently developed or are undergoing development. One suggested drug selection algorithm is provided.

Rhythm management in atrial fibrillation--with a primary emphasis on pharmacological therapy: Part 2

Atrial fibrillation (AF) is the most common, sustained, symptomatic tachyarrhythmia that clinicians are called upon to manage. Management strategies include ventricular rate control coupled with anticoagulation, versus restoration and maintenance of sinus rhythm. Rate control may be achieved pharmacologically, with agents that impair AV nodal conduction directly and/or by increasing parasympathetic/sympathetic balance, or by modifying or ablating the AV nodal region anatomically. Rhythm control may be achieved by electrical or pharmacological conversion followed by maintenance of sinus rhythm by pharmacological (or occasionally ablative) therapies. This article will present current approaches to rate and rhythm control issues in AF. Part 1, published previously, dealt with rate control. Part 2, the current article, details approaches to the restoration of sinus rhythm by electrical and pharmacological means. The former may use transthoracic or catheter-based energy delivery systems. The latter may use intravenous or oral drug approaches. Part 3, to be published in a subsequent edition of PACE will deal with the maintenance of sinus rhythm.

Rhythm management in atrial fibrillation--with a primary emphasis on pharmacological therapy: Part 1

Atrial fibrillation (AF) is the most common, sustained, symptomatic tachyarrhythmia that clinicians are called upon to manage. Management strategies include ventricular rate control coupled with anticoagulation, versus restoration and maintenance of sinus rhythm. Rate control may be achieved pharmacologically, with agents that impair AV nodal conduction directly and/or by increasing parasympathetic/sympathetic balance, or by modifying or ablating the AV nodal region anatomically. Rhythm control may be achieved by electrical or pharmacological conversion followed by maintenance of sinus rhythm by pharmacological (or occasionally ablative) therapies. This article will present current approaches to rate and rhythm control issues in AF. Part 1, the current manuscript, details approaches to rate control and includes a drug selection algorithmic conclusion. It also introduces the subject of the pursuit of sinus rhythm. Parts 2 and 3, to be published in subsequent editions of PACE, will deal with therapeutic measures to restore and maintain sinus rhythm.

An inexpensive dual-excitation apparatus for fluorescence microscopy

Ion sensitive indicator molecules can be employed in conjunction with fluorescence microscopy in single cells to measure rapid changes in the intracellular concentration of several ionic species. A number of these probes (e.g. fura-2) require the capability of measuring emission intensity at two excitation wavelengths to quantitate properly intracellular ion concentration. We have developed a simple dual-excitation apparatus for use in such applications. The apparatus switches the excitation filter within 150 ms. This economical apparatus is well suited in situations where the ionic concentration of interest is changing relatively slowly. Moreover, by synchronizing the device's action with an external stimulus, rapid and reproducible ionic changes in excitable tissue also can be measured.