Case Study

PROJECT DETAILS


  • Category Cardiovascular Disease
  • RESEARCH TYPE Self Funded
  • RESEARCH YEAR 2019
  • Location USA

Case Study: Plant-Based Diet with Lipid Medications Superior to Stent in Restoring Aerobic Exercise Capacity to Middle-Aged Athlete

By Peter Megdal, Phd, independent researcher


A 55-year-old elite competitive cyclist noticed an abrupt 14% reduction in cycling power within a two year period. Asymptomatic, he sought a cardiac evaluation utilizing maximal exercise testing. The patient demonstrated horizontal ST segment depression at 90% of his maximal oxygen uptake, indicating cardiac ischemia. Upon angiography, three non-obstructive (<50%) and two obstructive (>60%) stenoses were characterized and the right coronary artery was stented. His three-month poststent maximal oxygen uptake declined 5%. After aggressive diet and lipid therapy, three-year follow-up testing showed no cardiac ischemia and a dramatic 20% increase in maximal oxygen uptake.


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Introduction

Atherosclerotic cardiovascular disease characterized by fatty plaques narrowing coronary arteries is the leading cause of mortality worldwide[1]. Endurance athletes are known to have atherosclerotic cardiovascular disease at rates similar to non-athletes. However, myocardial infarction and subsequent death may be substantially lower[2, 3]. Aerobic functional capacity of an athlete with moderate to severe disease can far exceed that of an aged-matched non-diseased sedentary counterpart[4]. Although it is understood that the aging process will ultimately reduce a person’s maximal oxygen uptake and therefore athletic performance, it is difficult to distinguish between simple age-related decline and disease-induced decline[5].

It is important to note that population studies for both masters athletes and the general population demonstrate an expected linear aerobic decline of approximately 0.5 to 1.0% per year from the mid-20’s [5-7]. For this reason, if an athlete, as illustrated herein, notices a persistent, unrecoverable and steep performance decline, there may be cause for concern – even in the absence of symptomatology. Several recent investigations have highlighted the fact that individuals with seemingly normal cholesterol and other risk-factors may have not only subclinical disease but also potentially life-threatening stenosis[4, 8, 9]. Highly trained older athletes might have an abnormal electrocardiogram without symptoms which may or may not be benign[10]. In fact, the only symptom an older athlete may experience might be a reduction in aerobic performance[11]. This decline might be attributed to the aging process and thus the dangers of atherosclerotic cardiovascular disease progression might be inadvertently missed or ignored. Because an athlete may feel “inoculated” from atherosclerotic cardiovascular disease though an active lifestyle, they may never seek cardiac screening, however evidence supports they are at similar risk to the general population[2, 4].


Materials and methods

Maximal oxygen uptake stress test:

The patient underwent a maximum oxygen stress test using a cycling ergometer with resistance increasing at a rate of 1 watt/2 seconds. A full-face mask was used, and gas exchange ratio was recorded to determine oxygen uptake. The exercise tests lasted approximately 15 minutes with an ending power of over 400 watts. This protocol matched the patient’s preferred sport of cycling closely and was therefore ideal because of his very high level of cycling fitness[12].

Cycling power meter measurements:

Cycling power output was measured in watts. The PowerTap® power meter is a rear wheel hub based device utilizing an internal strain gauge that electronically transmits real-time power data to a head unit when the bicycle is pedaled. It is accurate within +/- 2%[13]. There are considerable advantages of this type of measurement and recording: the device is portable, lightweight and can store several workouts. In addition, the data can be exported to various software packages for analysis which include weekly, monthly and yearly trends for power of different durations allowing for a full catalog of physical energy output for multiple interpretations. In this case, 20-minute average maximal power was used since the patient regularly competed in time-trial events of this duration. This provides an excellent aerobic test comparable to laboratory maximal oxygen uptake testing in terms of duration and power output.

Angiogram and Stenting:

An angiogram was performed utilizing the percutaneous trans-ulnar artery approach. The proximal left anterior descending artery had a 30% stenosis at the first diagonal branch, and the mid-portion had a 50% stenosis after the second diagonal branch. The first diagonal had a 50% stenosis at its ostium. The ostium of the second diagonal also had a 60% stenosis. The right coronary artery had a 65% stenosis proximally. The mid right coronary artery had a tandem 30-65% stenosis. A Medtronic Launcher JR4 guiding catheter of 6-French was inserted over a guidewire and engaged into the right coronary ostium. A Boston Scientific Promus Premier RX stent of 4.00 mm by 38 mm long was inserted over the wire under fluoroscopic guidance. The stent was placed across both lesions of the proximal and mid right coronary artery. The diagonal branches were not stented due to inaccessibility. Post-intervention imaging of the right coronary artery revealed a residual 5% stenosis.

Diet:

The therapeutic diet consisted of a low fat whole food plant-based fare including legumes, whole grains (bread, pasta, oatmeal), dark green and color-rich vegetables, and a complete assortment of fruits, similar to the diet investigated by Dean Ornish, Caldwell Esselstyn, and Colin Campbell[14-16]. No milk, meat or fish were consumed, and high fat foods such as olives, avocado, and nuts were seldom eaten. No added oils were used to cook or flavor food. The approximate macronutrient content was 12% total fat (95% unsaturated and monounsaturated, 5% saturated), 75% carbohydrate and 13% protein, 0% cholesterol. The diet was well tolerated and maintained throughout the study. Pre-intervention diet was the Standard American Diet, SAD , which was typical of what most people eat in the United States with high dairy meat, salt and refined sugar consumption. Approximately 40% calories were derived from fat; 15% from protein and 45% from carbohydrates.


Results

This 55-year-old competitive road cyclist noticed a sharp decline of 14% in his cycling performance as quantified by a rear wheel hub power meter (PowerTap®) measuring power in watts. His reduced aerobic power occurred rapidly within a two-year window and persisted for three more years. The patient sought a medical evaluation because he felt that the decline was unusual, particularly after subsequently optimizing his cycling training for three years with no rebound or improvement in performance. For the previous several years, the patient had what is generally regarded to be normal total cholesterol of 180 (mg/dL), LDL-c of 120 (mg/dL), and HDL-c of 50 (mg/dL), and plasma glucose of 85 (mg/dL). (Table 1)

This elite older cyclist profoundly improved his exercise capacity putatively through a low fat whole food plant-based diet, niacin, evolocumab (add in the final year) and his regular high-intensity cycling training. (Table 1) Although no follow up angiogram was obtained, and the carotid artery ultrasound was inconclusive for atherosclerotic regression (although no progression was noted), it is possible to infer that the treatment protocol did reduce the hemodynamically significant stenoses in the culprit epicardial arteries and increased luminal diameter, thereby increasing exercise capacity[17]. It is important to note that an increase nitric oxide could be responsible for the increase in exercise capacity and the elimination of ischemia as demonstrated during stress testing since the low fat whole food plant-based diet purportedly leads to nitric oxide improvements, but this is unlikely since the patient undertook varying doses of isobromide dinitrate without an increase in exercise capacity[18]. The patient improved beyond his pre-diagnosis physical performance to win his first ever regional cycling championship along with a silver medal at a national championship.


Discussion

Aging athletes can possess extraordinarily high exercise capacity with concomitant ischemic cardiac pathology[4]. There are potentially millions of older athletic competitors that could be put at risk if physicians are not mindful of this fact. In this case, a national caliber athlete determined to train hard and perform at an elite level identified early but significant disease. The patient was stented and first prescribed a maximum statin dose but was found to be statin intolerant with muscle aches and fatigue. The notion of reducing this patient’s LDL-c through diet and medication to stabilize and possibly reverse plaque progression was derived from several studies that demonstrated that reversing atherosclerosis is possible[14, 19]. With the most recent study corroborating that there are no advantages for exercise tolerance with the use of stents, this patient achieved remarkable exercise capacity and elimination of cardiac ischemia through lifestyle changes and optimal medical therapy. Strictly whole food plant-based diets have demonstrated cholesterol lowering comparable to statins[20]. Decades of data on the efficacy of immediate-release niacin are robust and demonstrate reduced total cholesterol, increase HDL-c, and decrease LDL-c. Despite recent reports downplaying niacin efficacy, some studies used niacin either paired with a statin or with the prostaglandin inhibitor laropiprant which may have interfered with niacin’s mechanism of action[21, 22].

Current data do not support the use of stents for increased survival in patients with stable coronary artery disease, most likely because the underlying disease is not sufficiently treated[23]. That is to say, atherosclerotic disease is a lifestyle disease and should be treated as such. Statin therapy can be useful in reducing future acute coronary syndromes as compared to placebo but has limited efficacy particularly given many patients discontinue statin therapy after a year due to intolerance or other reasons[24].

With many aging athletes at risk atherosclerotic heart disease, perhaps it is necessary for physicians to rethink options for both identifying and treating this chronic disease synergistically with sustainable lifestyle modifications and effective medicines as supported by the body of medical evidence.

Conflict of interest: None

Financial support: self funded

Author contribution: Peter Megdal researched, wrote, assembled and proofed this manuscript


References

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[2] B.A. Taylor, A.L. Zaleski, J.A. Capizzi, K.D. Ballard, C. Troyanos, et al., Influence of chronic exercise on carotid atherosclerosis in marathon runners, BMJ Open 4(2) (2014) e004498.

[3] P.D. Thompson, B.A. Franklin, G.J. Balady, S.N. Blair, D. Corrado, et al., P.A. American Heart Association Council on Nutrition, Metabolism, C. American Heart Association Council on Clinical, M. American College of Sports, Exercise and acute cardiovascular events placing the risks into perspective: a scientific statement from the American Heart Association Council on Nutrition, Physical Activity, and Metabolism and the Council on Clinical Cardiology, Circulation 115(17) (2007) 2358-68.

[4] C.A. Rust, B. Knechtle, T. Rosemann, Exercise electrocardiogram testing in two brothers with different outcome – a case study exercise testing in master cyclists, Int J Gen Med 6 (2013) 495-501.

[5] S. Trappe, E. Hayes, A. Galpin, L. Kaminsky, et al., New records in aerobic power among octogenarian lifelong endurance athletes, J Appl Physiol (1985) 114(1) (2013) 3-10.

[6] A.S. Jackson, E.F. Beard, L.T. Wier, R.M. Ross, J.E. Stuteville, et al., Changes in aerobic power of men, ages 25-70 yr, Medicine and science in sports and exercise 27(1) (1995) 113-20.

[7] M.L. Pollock, L.J. Mengelkoch, J.E. Graves, D.T. Lowenthal, M.C. Limacher, et al., Twenty-year followup of aerobic power and body composition of older track athletes, J Appl Physiol (1985) 82(5) (1997) 1508-16.

[8] L. Fernandez-Friera, V. Fuster, B. Lopez-Melgar, B. Oliva, J.M. Garcia-Ruiz, et al., Normal LDLCholesterol Levels Are Associated With Subclinical Atherosclerosis in the Absence of Risk Factors, Journal of the American College of Cardiology 70(24) (2017) 2979-2991.

[9] N. Shah, C. Wong, N. Cox, A.M. Kelly, K. Soon, Prevalence of Asymptomatic Coronary Heart Disease in the Siblings of Young Myocardial Infarction Patients as Detected by Coronary Computer Tomography Angiography: A Pilot Study, Heart Lung Circ (2017).

[10] F.M. Quattrini, A. Pelliccia, R. Assorgi, F.M. DiPaolo, et al., Benign clinical significance of J-wave pattern (early repolarization) in highly trained athletes, Heart rhythm : the official journal of the Heart Rhythm Society 11(11) (2014) 1974-82.

[11] A. Pelliccia, B.J. Maron, F. Culasso, F.M. Di Paolo, A. Spataro, et al., Clinical significance of abnormal electrocardiographic patterns in trained athletes, Circulation 102(3) (2000) 278-84.

[12] F. Lothian, M.R. Farrally, A comparison of methods for estimating oxygen uptake during intermittent exercise, J Sports Sci 13(6) (1995) 491-7.

[13] A.S. Gardner, S. Stephens, D.T. Martin, E. Lawton, H. Lee, et al., Accuracy of SRM and power tap power monitoring systems for bicycling, Medicine and science in sports and exercise 36(7) (2004) 12528.

[14] D. Ornish, S.E. Brown, L.W. Scherwitz, J.H. Billings, W.T. Armstrong, et al., Can lifestyle changes reverse coronary heart disease? The Lifestyle Heart Trial, Lancet 336(8708) (1990) 129-33.

[15] T.C. Campbell, B. Parpia, J. Chen, Diet, lifestyle, and the etiology of coronary artery disease: the Cornell China study, The American journal of cardiology 82(10B) (1998) 18T-21T.

[16] C.B. Esselstyn, Jr., Updating a 12-year experience with arrest and reversal therapy for coronary heart disease (an overdue requiem for palliative cardiology), The American journal of cardiology 84(3) (1999) 339-41, A8.

[17] G. Schlierf, G. Schuler, R. Hambrecht, J. Niebauer, K. Hauer, et al., Treatment of coronary heart disease by diet and exercise, J Cardiovasc Pharmacol 25 Suppl 4 (1995) S32-4.

[18] P. Tuso, S.R. Stoll, W.W. Li, A plant-based diet, atherogenesis, and coronary artery disease prevention, Perm J 19(1) (2015) 62-7.

[19] D. Ornish, Intensive Lifestyle Changes for Reversal of Coronary Heart Disease, Jama 280(23) (1998) 2001.

[20] H.R. Ferdowsian, N.D. Barnard, Effects of plant-based diets on plasma lipids, The American journal of cardiology 104(7) (2009) 947-56.

[21] B.G. Brown, X.Q. Zhao, Nicotinic acid, alone and in combinations, for reduction of cardiovascular risk, The American journal of cardiology 101(8A) (2008) 58B-62B.

[22] C. Labos, J.M. Brophy, G. Thanassoulis, Placing HPS2-THRIVE in context using Bayesian analysis, International journal of cardiology 195 (2015) 203-4.

[23] R. Al-Lamee, D. Thompson, H.M. Dehbi, S. Sen, K. Tang, et al., Percutaneous coronary intervention in stable angina (ORBITA): a double-blind, randomised controlled trial, Lancet (2017).

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Key Words: Low fat whole-food plant based diet, maximal oxygen uptake, ST segment depression, stent, atherosclerosis, ischemia, cycle ergometry, athlete

Abbreviations: LDL-c, low-density lipoprotein; HDL-c, high-density lipoprotein; V02max, maximal oxygen uptake; Standard American Diet, SAD

Figure 1. Sequential electrocardiograms. These 5 electrocardiograms illustrate ST-segment depressions (red lines indicate slope) in the final minute (HR exceeding 170) of the maximal bicycle ergometer exercise test. Each one resolved after only 30 seconds of rest (not shown). Note that horizontal ST segments indicate possible cardiac ischemia due to stenosis. The September 2014, December 2014 and October 2016 had only two up-sloping depressed ST segment (lead V6-September 2014 and lead V4December 2014) indicating cardiac ischemia. The August 2015 and September 2017 had up-sloping ST segments (except lead V- August 2015) indicating no cardiac ischemia. The very late onset of the ST depression at near maximal exertion along with rapid resolution might indicate false positives. However, the angiographic studies clearly demonstrated that the patient had hemodynamically significant lesions inducing cardiac ischemia.

 

Figure 2. Cycling 20-minute power output curves. The patient reported this dramatic decline in cycling performance between the year 2009 and 2011. This 14% drop in power output far exceeds the expected 0.5% decline per year[6, 7].

Table 1. Patient characteristics. This 55-year-old patient’s weight fell throughout the study period with rising maximal oxygen uptake to 65.4 mL/kg/min. The 80(mg) pravastatin dose of was discontinued due to intolerance but resulted in a LDL-c of 104 (mg/dL). However, the patient found comparable LDL-c lowering effects following a low fat whole-food plant-based diet with add-on 1000mg instant release niacin, LDL-c of 91(mg/dL). Although cardiac ischemia was noted again in 2016, maximal oxygen uptake continued to rise, and no ischemia was recorded in 2017.