A 79-Year-Old Man With Aortic Stenosis

AUTHOR:
Ronald N. Rubin, MD^1,2—Series Editor

AFFILIATIONS:
¹Lewis Katz School of Medicine at Temple University, Philadelphia, Pennsylvania
²Department of Medicine, Temple University Hospital, Philadelphia, Pennsylvania

CITATION:
Rubin RN. A 79-year-old man with aortic stenosis. Consultant. 2021;61(5):e17-e19. doi:10.25270/con.2021.05.00003

DISCLOSURES:
The author reports no relevant financial relationships.

CORRESPONDENCE:
Ronald N. Rubin, MD, Temple University Hospital, 3401 N Broad Street, Philadelphia, PA 19140 (blooddocrnr@yahoo.com)

A 79-year-old man is being evaluated for aortic stenosis. He is known to have had aortic stenosis for the last several years, with serial clinical follow-up visits for symptoms and noninvasive tests for aortic stenosis parameters.

One year ago, his transaortic valve gradient was 44 mm Hg and jet velocity was 3.5 cm/sec. He is a lifelong heavy smoker, and results of a positron emission tomography (PET) scan showed limited lung function and capacity such that surgical aortic valve replacement (SAVR) was deemed too risky at that time. He denies angina and congestive heart failure (CHF) symptoms, but his chronic obstructive pulmonary disease (COPD) renders an accurate evaluation of this difficult, since his ambulation capacity and universe are limited. His cardiac ejection fraction has been in the range of 50% to 59%.

A battery of test results now shows progression of his aortic stenosis such that the gradient is now 55 mm Hg with an aortic valve area of 0.9 cm² and jet velocity of 4.0 cm/sec. His ejection fraction remains at 50%. However, a chest radiograph revealed a new speculated mass of 4 cm in diameter in the right lung proximally with bilateral mediastinal adenopathy. PET scan findings have been markedly consistent with a diagnosis of bronchogenic carcinoma of the mass and mediastinal lymph nodes.

Physical examination findings reveal a thin man who is comfortable at rest. His blood pressure is 105/75 mm Hg, pulse is 96 bpm, and respiration is 16 br/min. A significant delay of the carotid pulsation into the neck is noted. His chest has diminished breath sounds, but bilateral fine wheezes are present. His cardiac rhythm is regular, and a coarse, rasping systolic murmur is heard over the precordium. Trace pedal edema is present. 

Answer and discussion on next page.

Correct Answer: A

Aortic stenosis remains an important, interesting, and ever-evolving topic for review, as I have periodically done over the years in this column. The condition is a classic in medicine and will become even more common as the population ages, as well as because of the therapeutic and diagnostic “arms race,” so to speak, with newer techniques for evaluation and treatment appearing with rapidity.

The main focus of the presented case is the current universe of treatment modalities and how to adjudicate their use. But before we get to the case, here is a brief overall review of severe aortic stenosis demographics, clinical features, and core evaluations. Aortic stenosis will usually have a long natural history beginning with an often-incidental finding of a rasping, classically “diamond shaped,” systolic murmur that can be confirmed as aortic stenosis noninvasively via an echocardiography scan. Follow-up is clinical, regarding the onset of the ominous hallmark findings of angina pectoris, syncope, or CHF. These days, even more detailed and accurate follow-up using noninvasive Doppler ultrasonography scanning will measure transaortic valve gradient, valve orifice, and transvalvular jet velocity to determine when aortic stenosis develops into severe aortic stenosis. Commonly accepted values for hemodynamic severe aortic stenosis includes a valve gradient of more than 40 mm Hg, valve orifice of less than 0.9 to 1.0 cm², and/or transvalvular jet velocity of 4.0 cm/sec or higher.¹

Once severe aortic stenosis has developed, there is a 2-year mortality of about 50%,² and decisions regarding some form of intervention must be made, because—quite simply—no medical therapy (eg, diuresis, angiotensin-converting-enzyme inhibitors) meaningfully improves prognosis. The presented patient has reached this point, and the potential answers address which alternative is appropriate according to the best available data and guidelines.

When patient characteristics allow, some form of aortic valve replacement (such as SARV, answer C) is recommended, which requires open cardiac surgery.¹ This requires careful evaluation of surgical mortality risk (high risk, > 8% 30-day mortality²) and often will not be chosen for most patients aged older than 80 years. The presented patient’s findings show a rather prohibitive perioperative risk related to significant COPD symptoms, and he is close to age 80 years such that, even one year previously, he was not considered able to undergo SAVR, which remains a poor choice now despite the worsening hemodynamic numbers.

Answers B and D relate to the newer transcatheter aortic valve replacement (TAVR) procedure, which is far less invasive with less procedural risk and has, therefore, become an alternative for the 30% of patients with severe aortic stenosis who are not candidates for SAVR.^1,2 Current and newly revised guidelines strongly recommend the use of either SAVR or TAVR for symptomatic patients with severe aortic stenosis (strong, level A) and the use of TAVR for symptomatic patients with aortic stenosis with only an intermediate (4%-8%) surgical risk.^1,2 Thus, one might argue initially that TAVR might fit the presented patient, but there are 2 subtle issues here. First, despite his cardiodynamic numbers indicating severe aortic stenosis, he is essentially asymptomatic. Second is the unfortunate and obvious fact that he now has evidence of bronchogenic carcinoma of significance. Regarding the first, the classic indication for procedure, even TAVR, is symptomatic disease. There is evolving opinion that using even more refined cardiac follow-up and testing for hemodynamic and structural changes in asymptomatic patients (eg, B-type natriuretic peptide, gadolinium scanning for chamber size and wall thickness) can even more accurately pinpoint the prognosis, favoring timing of TAVR.^3,4 But these are not standards of care as of yet.

And even as important in the presented case, there is a bronchogenic carcinoma of at least stage 3b present with its own ominous prognosis, such that the strong recommendation from current guidelines is that even TAVR should not be offered in situations of extreme frailty or serious life-shortening comorbid conditions such as his advanced bronchogenic carcinoma.² A commonly used prognosis is 12 months, and coupling the patient’s yet-asymptomatic aortic stenosis state with the lung carcinoma prognosis—which, if not 12 months, is not that much longer—answers B and D are not optimal here. An incidental fact added to the adverse effects of TAVR is the thickening and deterioration of the valve with potential risk for thromboembolic sequelae ranging from 7% to 15% of patients.⁵ In short, answer B, using an Xa inhibitor such as rivaroxaban, adds nothing to the prevention of symptoms yet causes increased risk for serious bleeding.⁵ Therefore, it is actually an incorrect choice on its own account.

So, after evaluating the most current literature and guidelines and adjusting for the very guarded and limited overall prognosis here, the most appropriate management for the presented patient is answer A, waiting for aortic stenosis symptoms to occur and reacting if/when that happens with a palliative maneuver such as balloon valvuloplasty (another strong guideline recommendation) to address symptoms and temporarily improve functional status.^2,6 Although the effect of this approach is suboptimal, it is the most appropriate answer here.

Patient Follow-Up

As addressed in the text, there were multiple reasons that made the patient a very poor SAVR candidate (eg, COPD with poor pulmonary function, the discovery of a new and rapidly growing bronchogenic carcinoma, and even the patient’s age). In fact, this patient also was not a candidate for TAVR, which is used more commonly in medically frail patients with aortic stenosis. A cancer diagnosis was made, with the patient’s life expectancy less than 12 months, which is actually a strong contraindication in the most recent guidelines.

For now, management will be expectant as long as the patient can at least minimally function within his home. A balloon valvuloplasty can be considered for palliation of more severe symptoms if they occur prior to bronchogenic carcinoma complications.

What’s the Take Home?

Both the natural history and management strategies for the most classical and common valvular lesion of aortic stenosis continue to evolve. Ongoing studies have shown the newer, less invasive technique called TAVR to be a viable alternative to traditional SAVR for many of the 30% of patients with aortic stenosis who are not candidates for SAVR. As a result, we have to even further subclassify, stage, and follow patients with aortic stenosis so as to be able to most accurately determine the most appropriate time for intervention and which is the most risk/benefit optimal choice of procedure for an individual patient.

Recently revised guidelines clearly recommend SAVR or TAVR for symptomatic patients with aortic stenosis who have “severe” aortic stenosis by traditional criteria of valve size, gradient, and aortic jet velocity. TAVR is recommended when it is judged that SAVR would carry prohibitive surgical risk. It also seems that as experience with TAVR accrues, it may become an equivalent option. Even in patients with lower surgical risk and despite the expanding efficacy and safety profile of TAVR, it is not recommended in patients with a life expectancy from comorbidities of less than one year.

References

1. Saikrishnan N, Kumar G, Sawaya FJ, Lerakis S, Yoganathan AP. Accurate assessment of aortic stenosis: a review of diagnostic modalities and hemodynamics. Circulation. 2014;129(2):244-253. https://doi.org/10.1161/circulationaha.113.002310

2. Dia A, Cifu AS, Shah AP. Management of patients with severe aortic stenosis with transcatheter valve replacement. JAMA. 2019;321(15):1527-1528. https://doi.org/10.1001/jama.2019.1336

3. Kang DH, Park SJ, Lee SA, et al. Early surgery or conservative care for asymptomatic aortic stenosis. N Engl J Med. 2020;382(2):111-119. https://doi.org/10.1056/nejmoa1912846

4. Lancellotti P, Vannan MA. Timing of intervention in aortic stenosis. N Engl J Med. 2020;382(2):191-193. https://doi.org/10.1056/nejme1914382

5. De Backer O, Dangas GD, Jilaihawi H, et al. Reduced leaflet motion after transcatheter aortic-valve replacement. N Engl J Med. 2020;382(2):130-139. https://doi.org/10.1056/nejmoa1911426

6. Mack MJ, Leon MB, Thourani VH, et al. Transcatheter aortic-valve replacement with a balloon-expandable valve in low-risk patients. N Engl J Med. 2019;380(18):1695-1705. https://doi.org/10.1056/nejmoa181405